tag:blogger.com,1999:blog-34324548403555310362024-03-19T00:16:57.696-07:00MCQs preparation for Engineering & Top Interview Questions and AnswersPrepare Top Interview Questions and Answers for Civil Engineering Interview Questions, Mechanical Engineering Interview Questions, Electrical Engineering Interview Questions, Online preparation tests for Engineering Students.engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.comBlogger1100125tag:blogger.com,1999:blog-3432454840355531036.post-34162178801654638902019-05-02T04:08:00.003-07:002019-05-09T17:12:03.875-07:00Common EDC Lab Viva Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue;">Tricky ECE VIVA Questiions and Answers for Engineering students.</span></h3>
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<b><br /></b>
<b>1. What is Electronic?</b><br />
The study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles.<br />
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<b>2. What is communication?</b><br />
Communication means transferring a signal from the transmitter which passes through a medium then the output is obtained at the receiver. (or)communication says as transferring of message from one place to another place called communication.<br />
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<b>3. Different types of communications? Explain.</b><br />
Analog and digital communication.<br />
As a technology, analog is the process of taking an audio or video signal (the human voice) and translating it into electronic pulses. Digital on the other hand is breaking the signal into a binary format where the audio or video data is represented by a series of "1"s and "0"s.<br />
Digital signals are immune to noise, quality of transmission and reception is good, components used in digital communication can be produced with high precision and power consumption is also very less when compared with analog signals.<br />
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<b>4. What is sampling?</b><br />
The process of obtaining a set of samples from a continuous function of time x(t) is referred to as sampling.<br />
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<b>5. State sampling theorem?</b><br />
It states that, while taking the samples of a continuous signal, it has to be taken care that the sampling rate is equal to or greater than twice the cut off frequency and the minimum sampling rate is known as the Nyquist rate.<br />
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<b>6. What is cut-off frequency?</b><br />
The frequency at which the response is -3dB with respect to the maximum response.<br />
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<b>7. What is pass band?</b><br />
Passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.<br />
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<b>8. What is stop band?</b><br />
A stopband is a band of frequencies, between specified limits, in which a circuit, such as a filter or telephone circuit, does not let signals through, or the attenuation is above the required stopband attenuation level.<br />
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<b>9. Explain RF?</b><br />
Radio frequency (RF) is a frequency or rate of oscillation within the range of about 3 Hz to 300 GHz. This range corresponds to frequency of alternating current electrical signals used to produce and detect radio waves. Since most of this range is beyond the vibration rate that most mechanical systems can respond to, RF usually refers to oscillations in electrical circuits or electromagnetic radiation.<br />
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<b>10. What is modulation? And where it is utilized?</b><br />
Modulation is the process of varying some characteristic of a periodic wave with an external signals.<br />
Radio communication superimposes this information bearing signal onto a carrier signal.<br />
These high frequency carrier signals can be transmitted over the air easily and are capable of travelling long distances.<br />
The characteristics (amplitude, frequency, or phase) of the carrier signal are varied in accordance with the information bearing signal.<br />
Modulation is utilized to send an information bearing signal over long distances.<br />
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<b>11. What is demodulation?</b><br />
Demodulation is the act of removing the modulation from an analog signal to get the original baseband signal back. Demodulating is necessary because the receiver system receives a modulated signal with specific characteristics and it needs to turn it to base-band.<br />
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<b>12. Name the modulation techniques?</b><br />
For Analog modulation--AM, SSB, FM, PM and SM<br />
Digital modulation--OOK, FSK, ASK, Psk, QAM, MSK, CPM, PPM, TCM, OFDM<br />
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<b>13. Explain AM and FM?</b><br />
AM-Amplitude modulation is a type of modulation where the amplitude of the carrier signal is varied in accordance with the information bearing signal.<br />
FM-Frequency modulation is a type of modulation where the frequency of the carrier signal is varied in accordance with the information bearing signal.<br />
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<b>14. Where do we use AM and FM?</b><br />
AM is used for video signals for example TV. Ranges from 535 to 1705 kHz.<br />
FM is used for audio signals for example Radio. Ranges from 88 to 108 MHz.<br />
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<b>15. What is a base station?</b><br />
Base station is a radio receiver/transmitter that serves as the hub of the local wireless network, and may also be the gateway between a wired network and the wireless network.<br />
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16. How many satellites are required to cover the earth?<br />
3 satellites are required to cover the entire earth, which is placed at 120 degree to each other. The life span of the satellite is about 15 years.<br />
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<b>17. What is a repeater?</b><br />
A repeater is an electronic device that receives a signal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances without degradation.<br />
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<b>18. What is an Amplifier?</b><br />
An electronic device or electrical circuit that is used to boost (amplify) the power, voltage or current of an applied signal.<br />
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<b>19. Example for negative feedback and positive feedback?</b><br />
Example for –ve feedback is ---Amplifiers And for +ve feedback is – Oscillators.<br />
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<b>20. What is Oscillator?</b><br />
An oscillator is a circuit that creates a waveform output from a direct current input. The two main types of oscillator are harmonic and relaxation. The harmonic oscillators have smooth curved waveforms, while relaxation oscillators have waveforms with sharp changes.<br />
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<b>21. What is an Integrated Circuit?</b><br />
An integrated circuit (IC), also called a microchip, is an electronic circuit etched onto a silicon chip. Their main advantages are low cost, low power, high performance, and very small size.<br />
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<b>22. What is crosstalk?</b><br />
Crosstalk is a form of interference caused by signals in nearby conductors. The most common example is hearing an unwanted conversation on the telephone. Crosstalk can also occur in radios, televisions, networking equipment, and even electric guitars.<br />
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<b>23. What is resistor?</b><br />
A resistor is a two-terminal electronic component that opposes an electric current by producing a voltage drop between its terminals in proportion to the current, that is, in accordance with Ohm's law:<br />
V = IR.<br />
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<b>25. What is inductor?</b><br />
An inductor is a passive electrical device employed in electrical circuits for its property of inductance. An inductor can take many forms.<br />
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<b>26. What is conductor?</b><br />
A substance, body, or device that readily conducts heat, electricity, sound, etc. Copper is a good conductor of electricity.<br />
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<b>27. What is a semi conductor?</b><br />
A semiconductor is a solid material that has electrical conductivity in between that of a conductor and that of an insulator(An Insulator is a material that resists the flow of electric current. It is an object intended to support or separate electrical conductors without passing current through itself); it can vary over that wide range either permanently or dynamically.<br />
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<b>28. What is diode?</b><br />
In electronics, a diode is a two-terminal device. Diodes have two active electrodes between which the signal of interest may flow, and most are used for their unidirectional current property.<br />
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<b>29. What is transistor?</b><br />
In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. The transistor is the fundamental building block of computers, and all other modern electronic devices. Some transistors are packaged individually but most are found in integrated circuits.<br />
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<b>30. What is op-amp?</b><br />
An operational amplifier, often called an op-amp , is a DC-coupled high-gain electronic voltage amplifier with differential inputs[1] and, usually, a single output. Typically the output of the op-amp is controlled either by negative feedback, which largely determines the magnitude of its output voltage gain, or by positive feedback, which facilitates regenerative gain and oscillation.<br />
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<b>31. What is a feedback?</b><br />
Feedback is a process whereby some proportion of the output signal of a system is passed (fed back) to the input. This is often used to control the dynamic behaviour of the system.<br />
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<b>32. Advantages of negative feedback over positive feedback?</b><br />
Much attention has been given by researchers to negative feedback processes, because negative feedback processes lead systems towards equilibrium states. Positive feedback reinforces a given tendency of a system and can lead a system away from equilibrium states, possibly causing quite unexpected results.<br />
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<b>33. What is Barkhausen criteria?</b><br />
Barkhausen criteria, without which you will not know which conditions, are to be satisfied for oscillations.<br />
“Oscillations will not be sustained if, at the oscillator frequency, the magnitude of the product of the<br />
transfer gain of the amplifier and the magnitude of the feedback factor of the feedback network ( the magnitude of the loop gain ) are less than unity”.<br />
The condition of unity loop gain -Aβ = 1 is called the Barkhausen criterion. This condition implies that<br />
Aβ= 1and that the phase of - Aβ is zero.<br />
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<b>34. What is CDMA, TDMA, FDMA?</b><br />
Code division multiple access (CDMA) is a channel access method utilized by various radio communication technologies. CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. By contrast, time division multiple access (TDMA) divides access by time, while frequency-division multiple access (FDMA) divides it by frequency.<br />
An analogy to the problem of multiple access is a room (channel) in which people wish to communicate with each other. To avoid confusion, people could take turns speaking (time division), speak at different pitches (frequency division), or speak in different directions (spatial division). In CDMA, they would speak different languages. People speaking the same language can understand each other, but not other people. Similarly, in radio CDMA, each group of users is given a shared code. Many codes occupy the same channel, but only users associated with a particular code can understand each other.<br />
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<b>35. explain different types of feedback?</b><br />
Types of feedback:<br />
Negative feedback: This tends to reduce output (but in amplifiers, stabilizes and linearizes operation). Negative feedback feeds part of a system's output, inverted, into the system's input; generally with the result that fluctuations are attenuated.<br />
Positive feedback: This tends to increase output. Positive feedback, sometimes referred to as "cumulative causation", is a feedback loop system in which the system responds to perturbation (A perturbation means a system, is an alteration of function, induced by external or internal mechanisms) in the same direction as the perturbation. In contrast, a system that responds to the perturbation in the opposite direction is called a negative feedback system.<br />
Bipolar feedback: which can either increase or decrease output.<br />
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<b>36. What are the main divisions of power system?</b><br />
The generating system,transmission system,and distribution system.<br />
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<b>37. What is Instrumentation Amplifier (IA) and what are all the advantages?</b><br />
An instrumentation amplifier is a differential op-amp circuit providing high input impedances with ease of gain adjustment by varying a single resistor.<br />
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<b>38. What is meant by impedance diagram? </b><br />
The equivalent circuit of all the components of the power system are drawn and they are interconnected is called impedance diagram.<br />
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<b>39. What is the need for load flow study?</b><br />
The load flow study of a power system is essential to decide the best operation existing system and for planning the future expansion of the system. It is also essential for designing the power system.<br />
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<b>40. What is the need for base values? </b><br />
The components of power system may operate at different voltage and power levels. It will be convenient for analysis of power system if the voltage, power, current ratings of the components of the power system is expressed with referance to a common value called base value.<br />
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engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com27tag:blogger.com,1999:blog-3432454840355531036.post-59845255297364258102019-05-01T22:53:00.000-07:002019-05-09T17:12:22.662-07:00Hirred Embedded Systems based Viva Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue;">Frequently Asked Embedded Systems viva questions with answers:</span></h3>
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<b>Q1. What is an embedded system?</b><br />
Ans. An embedded system is a special purpose computer system which is completely encapsulated by device it control. It is a programmed hardware device in which the hardware chip is programmed with specific function. It is a combination of hardware and software.<br />
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<b>Q2. What are the characteristics of embedded system? </b><br />
Ans. The Characteristics of the embedded systems are as follows-<br />
1. Sophisticated functionality<br />
2. Real time behavior<br />
3. Low manufacturing cost<br />
4. Low power consumption<br />
5. User friendly<br />
6. Small size<br />
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<b>Q3. What are the types of embedded system? </b><br />
Ans. They are of 4 types<br />
1. General computing<br />
2. Control System<br />
3. Digital Signal Processing<br />
4. Communication and network<br />
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<b>Q4. What is digital signal controller ?</b><br />
Ans. DSC is 16 bit RISC machine that combines control advantages of micro-controller and digital signal processing to produce tightly coupled single chip-single instruction stream solution for embedded system design.<br />
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<b>Q5. What are the components of embedded system?</b><br />
Ans. Microcontroller, microprocessor, DSC, DSP, busses, system clock, Read only Memory(ROM), RAM, Real time clock these are the components of embedded system.<br />
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<b>Q6. Why we use embedded systems?</b><br />
Ans. Embedded systems avoid lots of electronic components and they have rich built in functionality. They reduces the cost and maintenance cost and the probability of failure of embedded system is less so embedded system are in very much use now a days.<br />
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<b>Q7. What are the languages used in embedded system?</b><br />
Ans. Assembly language and C are basically used for embedded system. Java and ADA are also preferred.<br />
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<b>Q8. How does combination of functions reduce memory requirement in embedded system?</b><br />
Ans. By using functions the amount of code that has to be dealt with is reduced thus redundancy is eliminated for everything common in function.<br />
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<b>Q9. What is the significance of watchdog timer in ES?</b><br />
Ans. It is a timing device which is set to predefined time interval and some task is to be performed at that time. It is used to reset original state when an inappropriate event take place.It is usually operated by counter device.<br />
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<b>Q10. What is the difference between mutexes and semaphores?</b><br />
Ans. Semaphores are the synchronization tool to overcome critical section problem.<br />
Mutex is also a tool that is used to provide deadlock free mutual exclusion. It protects access to every critical data item, if the data is locked and is in use,it either waits for the thread to finish or awakened to release the lock from its inactive state.<br />
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<b>Q11. What is the difference between FIFO and the memory?</b><br />
FIFO (first in first out) is a memory structure where data’s can be stored and retrieved. This is a queue where memory is a storage device which can hold data’s dynamically or at any desired locations and can be retrieved in any order.<br />
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<b>Q12. What is an anti-aliasing filter?</b><br />
Anti-aliasing filter reduces errors due to aliasing.<br />
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<b>Q13. How to implement a fourth order Butter worth LP filter at 1 KHz if sampling frequency is 8 KHz?</b><br />
A fourth order butter worth filter can be made as cascade of two second order LP filters with zeta of 0.924 and 0.383. One can use a bilinear transformation approach for realising second order LP filters. Using this technique described well in many texts, one can make second order LP filters and cascade them<br />
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<b>Q14. Is 8085 an embedded system?</b><br />
It’s not an embedded system. B’coz it will be a part of an embedded system and it does not work on any software.<br />
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<b> Q15.What is the role of segment register?</b><br />
In the 8086 processor architecture, memory addresses are specified in two parts called the segment and the offset. Segment values are stored in the segment registers. There are four or more segment registers: Code Segment (CS) contains segment of the current instruction (IP is the offset), Stack segment (SS) contain stack of the segment (SP is the offset), DS is the segment used by default for most data operations; ES is an extra segment register.<br />
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<b>Q16.What type of registers contains an INTEL CPU?</b><br />
Special function registers like accumulator, program controller (PC), data pointer (DPTR), TMOD and TCON (timing registers), 3 register banks with r0 to r7, Bit addressable registers like B.<br />
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<b> Q17. What is the difference between microprocessor and micro controller?</b><br />
Microprocessor is managers of the resources (I/O, memory) which lie out-side of its architecture.<br />
Micro controllers have I/O, memory etc. built into it and specifically designed for control.<br />
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<b>Q18. DMA deals with which address (physical/virtual addresses)?</b><br />
DMA deals with physical addresses. DMA controller is a device which directly drives the data and address bus during data transfer. So it is purely physical address.<br />
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<b> Q19. What is the difference between testing and verification?</b><br />
Verification is a front end process and testing is a post silicon process. Verification is to verify the functionality of the design during the design cycle. Testing is find manufacturing faults.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com11tag:blogger.com,1999:blog-3432454840355531036.post-89636982744262732282019-05-01T22:26:00.001-07:002019-05-09T17:12:43.930-07:00Recently Asked Microprocessors and Microcontroller Lab viva Questions with Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue;">Most Recently Asked MPMC Viva Questions with Answers:</span></h3>
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<b>1.What is a Microprocessor?</b><br />
Microprocessor is a CPU fabricated on a single chip, program-controlled device, which fetches the instructions from memory, decodes and executes the instructions.<br />
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<b>2. What is Instruction Set?</b><br />
It is the set of the instructions that the Microprocessor can execute.<br />
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<b>3. What is Bandwidth ?</b><br />
The number of bits processed by the processor in a single instruction.<br />
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<b>4. What is Clock Speed ?</b><br />
Clock speed is measured in the MHz and it determines that how many instructions a processor can processed.The speed of the microprocessor is measured in the MHz or GHz.<br />
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<b>5. What are the features of Intel 8086 ?</b><br />
Features:<br />
· Released by Intel in 1978<br />
· Produced from 1978 to 1990s<br />
· A 16-bit microprocessor chip.<br />
· Max. CPU clock rate:5 MHz to 10 MHz<br />
· Instruction set: x86-16<br />
· Package: 40 pin DIP<br />
· 16-bit Arithmetic Logic Unit<br />
· 16-bit data bus (8088 has 8-bit data bus)<br />
· 20-bit address bus - 220 = 1,048,576 = 1 meg<br />
· The address refers to a byte in memory.<br />
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<b>6.What are the flags in 8086?</b><br />
In 8086 Carry flag, Parity flag, Auxiliary carry flag, Zero flag, Overflow flag, Trace flag, Interrupt flag, Direction flag, and Sign flag.<br />
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<b>7.Why crystal is a preferred clock source?</b><br />
Because of high stability, large Q (Quality Factor) & the frequency that doesn’t drift with aging. Crystal is used as a clock source most of the times.<br />
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<b>8.What is Tri-state logic?</b><br />
Three Logic Levels are used and they are High, Low, High impedance state. The high and low are normal logic levels & high impedance state is electrical open circuit conditions. Tri-state logic has a third line called enable line.<br />
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<b>9.What happens when HLT instruction is executed in processor?</b><br />
The Micro Processor enters into Halt-State and the buses are tri-stated.<br />
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<b>10.What is Program counter?</b><br />
Program counter holds the address of either the first byte of the next instruction to be fetched for execution or the address of the next byte of a multi byte instruction, which has not been completely fetched. In both the cases it gets incremented automatically one by one as the instruction bytes get fetched. Also Program register keeps the address of the next instruction.<br />
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<b>11.What is 1st / 2nd / 3rd / 4th generation processor?</b><br />
The processor made of PMOS / NMOS / HMOS / HCMOS technology is called 1st / 2nd / 3rd / 4th generation processor, and it is made up of 4 / 8 / 16 / 32 bits.<br />
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<b>12.What is the Maximum clock frequency in 8086?</b><br />
5 Mhz is the Maximum clock frequency in 8086.<br />
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<b>13.What is meant by Maskable interrupts?</b><br />
An interrupt that can be turned off by the programmer is known as Maskable interrupt.<br />
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<b>14.What is Non-Maskable interrupts?</b><br />
An interrupt which can be never be turned off (ie. disabled) is known as Non-Maskable interrupt<br />
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<b>15.What are the different functional units in 8086?</b><br />
Bus Interface Unit and Execution unit, are the two different functional units in 8086.<br />
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<b>16.What are the various segment registers in 8086?</b><br />
Code, Data, Stack, Extra Segment registers in 8086.<br />
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<b>17.What does EU do?</b><br />
Execution Unit receives program instruction codes and data from BIU, executes these instructions and store the result in general registers.<br />
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<b>18.Which Stack is used in 8086? k is used in 8086?</b><br />
FIFO (First In First Out) stack is used in 8086.In this type of Stack the first stored information is retrieved first.<br />
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<b>19.What are the flags in 8086?</b><br />
In 8086 Carry flag, Parity flag, Auxiliary carry flag, Zero flag, Overflow flag, Trace flag, Interrupt flag, Direction flag, and Sign flag.<br />
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<b>20.What is SIM and RIM instructions?</b><br />
SIM is Set Interrupt Mask. Used to mask the hardware interrupts.<br />
RIM is Read Interrupt Mask. Used to check whether the interrupt is Masked or not.<br />
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<b>21.What are Flag registers?</b><br />
A:-Divided into 2 parts:-Condition code or status flags and machine control flags.<br />
S-Sign Flag:-Is to set when the result of any computation is negative.<br />
Z-Zero Flag:-Is to set if the result of the computation or comparison performed by the previous instruction is zero.<br />
C-Carry Flag:-Is set when there is carry out of MSB in case of addition or a borrow in case of subtraction.<br />
T-Trap Flag:-Is set,the processor enters the single step execution mode.<br />
I-Interrupt Flag:-Is set,the maskable interrupts are recognized by the CPU.<br />
D-Direction Flag:-Is set for autoincrementing or autodecrementing mode in string manipulation instructions.<br />
AC-Auxiliary Carry Flag:-Is set if there is a carry from the lowest nibble during addition or borrow for the lowest nibble.<br />
O-Overflow Flag:-Is setif the result of a signed operation is large enough to be accommodated in a destination register.<br />
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<b>22.Write the flags of 8086?</b><br />
The 8086 has nine flags and they are<br />
1. Carry Flag (CF) 6. Overflow Flag (OF)<br />
2. Parity Flag (PF) 7. Trace Flag (TF)<br />
3. Auxiliary carry Flag (AF) 8. Interrupt Flag (IF)<br />
4. Zero Flag (ZF) 9. Direction Flag (DF)<br />
5. Sign Flag (SF)<br />
<br />
<b>23. What are the interrupts of 8086?</b><br />
The interrupts of 8085 are INTR and NMI. The INTR is general maskable interrupt and NMI is non-maskable interrupt.<br />
<br />
<b>24. How clock signal is generated in 8086? What is the maximum internal clock frequency of 8086?</b><br />
The 8086 does not have on-chip clock generation circuit. Hence the clock generator chip, 8284 is connected to the CLK pin of8086. The clock signal supplied by 8284 is divided by three for internal use. The maximum internal clock frequency of8086 is 5MHz.<br />
<br />
<b>25. Write the special functions carried by the general purpose registers of 8086?</b><br />
The special functions carried by the registers of 8086 are the following.<br />
Register Special function<br />
1. AX 16-bit Accumulator<br />
2. AL 8-bit Accumulator<br />
3. BX Base Register 4. CX Count Register 5. DX .Data Register<br />
<br />
<b>26.What is the need for Port?</b><br />
The I/O devices are generally slow devices and their timing characteristics do not match with processor timings. Hence the I/O devices are connected to system bus through the ports.<br />
<br />
<b>27.What is a port?</b><br />
The port is a buffered I/O, which is used to hold the data transmitted from the microprocessor to I/O device or vice-versa.<br />
<b><br /></b>
<b>28.What is processor cycle (Machine cycle)?</b><br />
The processor cycle or machine cycle is the basic operation performed by the processor. To execute an instruction, the processor will run one or more machine cycles in a particular order.<br />
<br />
<b>29.What is Instruction cycle?</b><br />
The sequence of operations that a processor has to carry out while executing the instruction is called Instruction cycle. Each instruction cycle of a processor indium consists of a number of machine cycles.<br />
<br />
<b>30.What is fetch and execute cycle?</b><br />
In general, the instruction cycle of an instruction can be divided into fetch and execute cycles. The fetch cycle is executed to fetch the opcode from memory. The execute cycle is executed to decode theinstruction and to perform the work instructed by the instruction.<br />
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engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com6tag:blogger.com,1999:blog-3432454840355531036.post-37324810982343489372019-04-28T22:31:00.001-07:002019-04-28T22:31:31.807-07:00Top 10 MICROWAVE ENGINEERING LAB VIVA QUESTIONS AND ANSWERS<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue;">Latest Microwave Engineering VIVA Questions and Answers:</span></h3>
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<b>1. What is Microwave Engineering?</b><br />
Ans. Microwave engineering is the study and design of microwave circuits , components , and systems. Fundamental principles are applied to analysis , design and measurement techniin this field.The short wavelengths involved distinguish this discipline from electronic engineering . This is because there are different interactions with circuits, transmissions and propagation characteristics at microwave frequencies.a<br />
<br />
<b>2. Define s-matrix and its properties?</b><br />
Ans. In a microwave junction there is an interaction of three or more components.There will be an output port, in addition there may be reflection from the junction of other ports. Totally there may be many combination, these are represented easily using a matrix called S matrix.<br />
Properties of s- matrix<br />
1. it possess symmetric properties sij=sji<br />
2. it possess unitary property<br />
3. [s][s]*=[i]<br />
<br />
<b>3. Write the applications of microwave engineering?</b><br />
Ans. Following are the applications of microwave engineering-<br />
1. Antenna gain is proportional to the electrical size of the antenna. At higher frequencies, more antenna gain is therefore possible for a given physical antenna size, which has important consequences for implementing miniaturized microwave systems.<br />
2. More bandwidth can be realized at higher frequencies. Bandwidth is critically important because available frequency bands in the electromagnetic spectrum are being rapidly depleted.<br />
3. Microwave signals travel by line of sight are not bent by the ionosphere as are lower frequency<br />
signals and thus satellite and terrestrial communication links with very high capacities are possible.<br />
<br />
<b>4. Why is s-matrix used in MW analysis?</b><br />
Ans. Matrix is used in MW analysis to overcome the problem which occurs when H,Y & Z parameter are used in high frequencies.<br />
<br />
<b>5. What are the advantages of ABCD matrix?</b><br />
Ans. The advantages of ABCD matrix are as follows-<br />
1. They are used in power transmission lines<br />
2. They are helpful in case of cascade networks.<br />
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<b>6. What are junctions ? Give some example</b><br />
Ans. A microwave circuit consists of several microwave devices connected in some way to achieve the desired transmission of MW signal. The interconnection of two or more microwave may be regarded as MW junction.<br />
E.g.: TEE, HYBRID RING<br />
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<b>7. What are non-reciprocal devices ?Give two examples?</b><br />
Ans. The devices which are having the properties that the forward characteristics are not equal to the reverse characteristics are called non-reciprocal devices.<br />
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<b>8. What are the applications of reflex klystron?</b><br />
Ans. The main applications of a reflex klystron are as follows-<br />
1. Signal source in MW generator<br />
2. Local oscillators in receivers<br />
3. It is used in FM oscillator in low power MW links.<br />
4. In parametric amplifier as pump source.<br />
<br />
<b>9. What is the purpose of slow wave structures used in TWT amplifiers?</b><br />
Ans. Slow wave structures are special circuits that are used in microwave tubes to reduce wave velocity in a certain direction so that the electron beam and the signal wave can interact. In TWT, since the beam can be accelerated only to velocities that are about a fraction of the velocity of light, slow wave structures are used.<br />
<br />
<b>10.Give two examples for two port junctions?</b><br />
Ans. Following are the two examples of two port junctions-<br />
1. The junction of two rectangular guides of unequal height<br />
2. A symmetrical junction consisting of two similar rectangular guides joined by an Intermediate guide of greater width.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com6tag:blogger.com,1999:blog-3432454840355531036.post-39223237574702347272019-04-28T22:19:00.000-07:002019-04-28T22:19:01.469-07:00Recently Asked Digital image processing Viva Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<b><span style="color: blue;">Latest Digital image processing Viva Questions and Answers :</span></b></h3>
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<b><br /></b>
<b>1. Define Image?</b><br />
An image may be defined as two dimensional light intensity function f(x, y) where x and y denote spatial co-ordinate and the amplitude or value of f at any point (x, y) is called intensity or gray scale or brightness of the image at that point.<br />
<b><br /></b>
<b>2. What is Dynamic Range?</b><br />
The range of values spanned by the gray scale is called dynamic range of an image. Image will have high contrast, if the dynamic range is high and image will have dull washed out gray look if the dynamic range is low.<br />
<br />
<b>3. Define Brightness?</b><br />
Brightness of an object is the perceived luminance of the surround. Two objects with different surroundings would have identical luminance but different brightness.<br />
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<b>4. What do you meant by Gray level?</b><br />
Gray level refers to a scalar measure of intensity that ranges from black to grays and finally to white.<br />
<b><br /></b>
<b>5. What do you meant by Color model?</b><br />
A Color model is a specification of 3D-coordinates system and a subspace within that system where each color is represented by a single point.<br />
<br />
<b>6. List the hardware oriented color models?</b><br />
1. RGB model<br />
2. CMY model<br />
3. YIQ model<br />
4. HSI model<br />
<br />
<b>7. What is Hue and saturation?</b><br />
Hue is a color attribute that describes a pure color where saturation gives a measure of the degree to which a pure color is diluted by white light.<br />
<br />
<b>8. List the applications of color models?</b><br />
1. RGB model--- used for color monitors & color video camera<br />
2. CMY model---used for color printing<br />
3. HIS model----used for color image processing<br />
4. YIQ model---used for color picture transmission<br />
<br />
<b>9. What is Chromatic Adoption?</b><br />
The hue of a perceived color depends on the adoption of the viewer. For example,the American Flag will not immediately appear red, white, and blue of the viewer has been subjected to high intensity red light before viewing the flag. The color of the flag will appear to shift in hue toward the red component cyan.<br />
<br />
<b>10. Define Resolutions? </b><br />
Resolution is defined as the smallest number of discernible detail in an image.Spatial resolution is the smallest discernible detail in an image and gray level resolution refers to the smallest discernible change is gray level.<br />
<br />
<b>11. What is meant by pixel?</b><br />
A digital image is composed of a finite number of elements each of which has a particular location or value. These elements are referred to as pixels or image elements or picture elements or pixls elements.<br />
<br />
<b>12. Define Digital image? </b><br />
When x, y and the amplitude values of f all are finite discrete quantities , we call the image digital image.<br />
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<b>13. What are the steps involved in DIP?</b><br />
1. Image Acquisition<br />
2. Preprocessing<br />
3. Segmentation<br />
4. Representation and Description<br />
5. Recognition and Interpretation<br />
<br />
<b>14. What is recognition and Interpretation?</b><br />
Recognition means is a process that assigns a label to an object based on the information provided by its descriptors.Interpretation means assigning meaning to a recognized object.<br />
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<b>15. Specify the elements of DIP system?</b><br />
1. Image Acquisition<br />
2. Storage<br />
3. Processing<br />
4. Display<br />
<br />
<b>16. List the categories of digital storage?</b><br />
1. Short term storage for use during processing.<br />
2. Online storage for relatively fast recall.<br />
3. Archival storage for infrequent access.<br />
<br />
<b>17. What are the types of light receptors?</b><br />
The two types of light receptors are<br />
• Cones and<br />
• Rods<br />
<br />
<b>18. Differentiate photopic and scotopic vision ?</b><br />
Photopic vision Scotopic vision<br />
1. The human being can resolve the fine details with these cones because each one is connected to its own nerve end.<br />
2. This is also known as bright light vision.<br />
<b><br /></b>
<b>19. How cones and rods are distributed in retina?</b><br />
In each eye, cones are in the range 6-7 million and rods are in the range 75-150 million.<br />
<br />
<b>20. Define subjective brightness and brightness adaptation?</b><br />
Subjective brightness means intensity as preserved by the human visual system.Brightness adaptation means the human visual system can operate only from scotopic to glare limit. It cannot operate over the range simultaneously. It accomplishes this large variation by changes in its overall intensity.<br />
<br />
<b>21. Define weber ratio?</b><br />
The ratio of increment of illumination to background of illumination is called as web er ratio.(ie) Δi/i<br />
If the ratio (Δi/i) is small, then small percentage of change in intensity is needed (ie) good brightness adaptation.<br />
If the ratio (Δi/i) is large , then large percentage of change in intensity is needed (ie) poor brightness adaptation.<br />
<br />
<b>22. What is meant by mach band effect?</b><br />
Mach band effect means the intensity of the stripes is constant. Therefore it preserves the brightness pattern near the boundaries, these bands are called as mach band effect.<br />
<br />
<b>23. What is simultaneous contrast?</b><br />
The region reserved brightness not depend on its intensity but also on its background. All centre square have same intensity. However they appear to the eye to become darker as the background becomes lighter.<br />
<b><br /></b>
<b>24. What is meant by illumination and reflectance?</b><br />
Illumination is the amount of source light incident on the scene. It is represented as i(x, y).<br />
Reflectance is the amount of light reflected by the object in the scene. It is represented by r(x, y).<br />
<br />
<b>26. Define sampling and quantization?</b><br />
Sampling means digitizing the co-ordinate value (x, y).Quantization means digitizing the amplitude value. Several rods are connected to one nerve end. So it gives the overall picture of the image.This is also known as thin lightvision.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com2tag:blogger.com,1999:blog-3432454840355531036.post-39536139314492720822019-04-28T22:10:00.000-07:002019-04-28T22:10:40.020-07:00Top 30 C LANGUAGE VIVA QUESTIONS AND ANSWERS<div dir="ltr" style="text-align: left;" trbidi="on">
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<b><span style="color: blue;">Tricky C Language VIVA Questions with Answers:</span></b></h3>
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<br />
<b>1)Who invented C Language?</b><br />
Dennis Ritchie in 1972 developed a new language by inheriting the features of both BCPL and B and adding additional features. He named the language as just C.<br />
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<b>2) Who invented B Language?</b><br />
Ken Thomson at AT&T Bell Labs developed a language and named it B. Even the B language was found to have some short comings to support development of both business applications and system software.<br />
<b><br /></b><b>3) Who invented BCPL Language?</b><br />
Basic Combined Programming Language(BCPL) was developed by Martin Richards, Cambridge university.<br />
<br />
<b>4) Why C Language?</b><br />
C is one of the high level languages. It is a general purpose language, which means it can be used to write programs of any sort.<br />
<br />
<b>5) What are the features of C Langauges?</b><br />
In C one can write programs like that of high level languages as in COBOL, BASIC, FORTRAN etc. as well as it permits very close interaction with the inner workings of the computer.<br />
It is a general purpose programming language. It is usually called system programming language but equally suited to writing a variety of applications.<br />
It supports various data types.<br />
It follows the programming style based on fundamental control flow constructions for structured programming.<br />
Functions may be pre–defined or user defined and they may return values of basic types, structures, unions or pointers.<br />
<br />
<b> 6)What are the advantages of c language?</b><br />
Easy to write<br />
Rich set of operators and functions that are built–in<br />
Support for bit–wise operation<br />
Flexible use of pointers<br />
Direct control over the hardware<br />
Ability to access BIOS/DOS routines<br />
Interacting using Interrupts<br />
Ability to write TSR programs<br />
Ability to create .COM files<br />
Ability to create library files (.LIB)<br />
Ability to write interface programs<br />
Incorporating assembly language in C program<br />
<br />
<b>7) What are the disadvantages of c langauge?</b><br />
C is considered difficult to learn<br />
Because of its conciseness, the code can be difficult to follow<br />
It is not suited to applications that require a lot of report formatting and data file manipulation.<br />
<br />
<b> 8) What are the salient features of c languages?</b><br />
The following are the salient features of C language are :<br />
C is called a middle level language<br />
C supports structured design approach<br />
C is extensible<br />
C is rich in data types and operators<br />
C is portable<br />
<br />
<b> 9) What is a header file?</b><br />
Header files provide the definitions and declarations for the library functions. Thus, each header file contains the library functions along with the necessary definitions and declarations. For example, stdio.h, math.h, stdlib.h, string.h etc.<br />
<br />
<b>10) What is character set?</b><br />
Character set is the set of characters allowed and supported in the programming language. Generally a program is a collection of instructions, which contain groups of characters. Only a limited set of characters is allowed to write instructions in the program.<br />
<br />
<b>11) What is C token?</b><br />
The smallest individual units of a C program are known as tokens.<br />
<br />
<b>12) List the different types of C tokens?</b><br />
Constants<br />
Identifiers<br />
Keywords<br />
Operators<br />
Special symbols<br />
Strings<br />
<b><br /></b><b>13) What is a string?</b><br />
A string is a sequence of characters ending with NUL. It can be treated as a one–dimensional array of characters terminated by a NUL character.<br />
<br />
<b>14) What are qualifiers?</b><br />
Qualifiers or modifiers are identifiers that may precede the scalar data types (except float) to specify the number of bits used for representing the respective type of data in memory. The qualifiers in C are short, long, signed, and unsigned.<br />
<br />
<b>15) What is a function?</b><br />
A function is a set of statements to perform a specific task.<br />
<br />
<b>16) What is a constant?</b><br />
A constant is a value that does not change during the program execution. A constant used in C does not occupy memory.<br />
<br />
<b>17) What are the different types of constants?</b><br />
There are five types of constants. They are :<br />
Integer constants<br />
Floating point constants<br />
Character constants<br />
String literals<br />
Enumeration constants<br />
<br />
<b>18) What is variable?</b><br />
An identifier is used to identify and store some value. If the value of the identifier is changed during the execution of the program, then the identifier is known as variable.<br />
<br />
<b>19) What are the rules for the identifier?</b><br />
The first character must be an alphabet or underscore (_)<br />
Digits may be included in the variable<br />
The maximum number of characters in a word are 32 (It may vary depending upon the platform)<br />
No other special characters are allowed.<br />
<br />
<b> 20) What are global variables?</b><br />
Global Variables are those, which are required to be acccessed by all the functions defined after their declaration. So, the variables declared before the main {) can be acccessed by all the functions, which follow their declaration.<br />
<br />
<b>21) What is a keyword?</b><br />
Keywords are those words of C which have predefined meaning assigned by the C language. They form a part of the database required by the C compiler.<br />
<br />
<b>22) What are the different types of c instructions?</b><br />
There are basically three types of instructions in C are :<br />
Type Declaration Instruction<br />
Arithmetic Instruction<br />
Control Instruction<br />
<br />
<b> 23) What is an expression?</b><br />
Expression is defined as a combination of operands and operators to obtain some computation. Operands represent variables or values and The operator tells is what operation to be performed.<br />
<br />
<b>24) What are the types of data files?</b><br />
There are two types of data files :<br />
stream oriented or standard data files<br />
system oriented or low level data files<br />
<b><br /></b><b> 25) Why C is called a middle level language?</b><br />
C combines the features of both Assembly Level Languages (Low Level Languages) and Higher Level Languages. For this reason, C is referred to as a Middle Level Language. The feature of ALLs is that of enabling us to develop system level programs and the features of HLLs are those of higher degree of readability and machine independence.<br />
<br />
<b>26) How can variables be characterized?</b><br />
The variables can be categorized by storage class as well as by data type. The storage class specifies the portion of the program within which the variables are recognized.<br />
<br />
<b>27) Give the rules for variable declaration?</b><br />
The rules for variable declaration in C are given below :<br />
A variable name consists of alphabets, digits and the underscore (_) character<br />
The length of variable should be kept upto 8 characters though your system may allow upto 40 characters<br />
They must begin with an alphabet<br />
Some systems also recognize an underscore as the first character<br />
White space and commas are not allowed<br />
Any reserved word (keyword) cannot be used as a variable name.<br />
<br />
<b>28) What is the purpose of type declarations?</b><br />
The type declaration allow to create a synonym for other data types. Its syntax is type def type identifier; The declaration type def unsigned long int INTEGER<br />
<br />
<b>29) What is recursion?</b><br />
C language a function may call another function. When a function calls itself, it is referred to as recursive call and the process is known as recursion. C provides very good facilities for recursion.<br />
<br />
<b>30) What is data types?</b><br />
Data types refer to the classes of data that can be manipulated by C programs. The three fundamental data types supported by C are character, integer and real type.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com5tag:blogger.com,1999:blog-3432454840355531036.post-27676569676233012522019-04-27T05:52:00.001-07:002019-04-27T05:55:45.646-07:00Commonly Asked Java Programming VIVA Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue; font-size: 18px;">Top 30 Viva Questions & Answers for Java Developers:</span></h3>
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<b><br /></b>
<b>1.What is JVM?</b><br />
The Java interpreter along with the run time environment required to run the Java application in called as Java virtual machine(JVM)<br />
<br />
<b> 2. What is the most important feature of Java?</b><br />
Java is a platform independent language.<br />
<br />
<b>3. What do you mean by platform independence?</b><br />
Platform independence means that we can write and compile the java code in one platform (eg Windows) and can execute the class in any other supported platform eg (Linux,Solaris,etc).<br />
<br />
<b> 4. What is the difference between a JDK and a JVM?</b><br />
JDK is Java Development Kit which is for development purpose and it includes execution environment also. But JVM is purely a run time environment and hence you will not be able to compile your source files using a JVM.<br />
<br />
<b>5. What is the base class of all classes?</b><br />
java.lang.Object<br />
<b><br /></b>
<b> 6. What are the access modifiers in Java?</b><br />
There are 3 access modifiers. Public, protected and private, and the default one if no identifier is specified is called friendly, but programmer cannot specify the friendly identifier explicitly.<br />
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<b> 7. What is are packages?</b><br />
A package is a collection of related classes and interfaces providing access protection and namespace management.<br />
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<b> 8. What is meant by Inheritance and what are its advantages?</b><br />
Inheritance is the process of inheriting all the features from a class. The advantages of inheritance are reusability of code and accessibility of variables and methods of the super class by sub classes.<br />
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<b> 9. What is the difference between superclass and subclass?</b><br />
A super class is a class that is inherited whereas sub class is a class that does the inheriting.<br />
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<b> 10. What is an abstract class?</b><br />
An abstract class is a class designed with implementation gaps for sub classes to fill in and is deliberately incomplete.<br />
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<b> 11. What are the states associated in the thread?</b><br />
Thread contains ready, running, waiting and dead states.<br />
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<b> 12. What is synchronization?</b><br />
Synchronization is the mechanism that ensures that only one thread is accessed the resources at a time.<br />
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<b> 13. What is deadlock?</b><br />
When two threads are waiting each other and can’t precede the program is said to be deadlock.<br />
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<b> 14. What is an applet?</b><br />
Applet is a dynamic and interactive program that runs inside a web page displayed by a java capable browser<br />
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<b> 15. What is the lifecycle of an applet?</b><br />
init() method - Can be called when an applet is first loaded<br />
start() method - Can be called each time an applet is started.<br />
paint() method - Can be called when the applet is minimized or maximized.<br />
stop() method - Can be used when the browser moves off the applet’s page.<br />
destroy() method - Can be called when the browser is finished with the applet.<br />
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<b> 16. How do you set security in applets?</b><br />
using setSecurity Manager() method<br />
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<b> 17. What is a layout manager and what are different types of layout managers available in java AWT?</b><br />
A layout manager is an object that is used to organize components in a container. The different layouts are available are FlowLayout, BorderLayout, CardLayout, GridLayout and GridBagLayout<br />
<br />
<b> 18. What is JDBC?</b><br />
JDBC is a set of Java API for executing SQL statements. This API consists of a set of classes and interfaces to enable programs to write pure Java Database applications.<br />
<br />
<b> 19. What are drivers available?</b><br />
a) JDBC-ODBC Bridge driver b) Native API Partly-Java driver<br />
c) JDBC-Net Pure Java driver d) Native-Protocol Pure Java driver<br />
<br />
<b>20. What is stored procedure?</b><br />
Stored procedure is a group of SQL statements that forms a logical unit and performs a particular task. Stored Procedures are used to encapsulate a set of operations or queries to execute on database. Stored procedures can be compiled and executed with different parameters and results and may have any combination of input/output parameters.<br />
<b><br /></b>
<b> 21. What is the Java API?</b><br />
The Java API is a large collection of ready-made software components that provide many useful capabilities, such as graphical user interface (GUI) widgets.<br />
<br />
<b> 22. Why there are no global variables in Java?</b><br />
Global variables are globally accessible. Java does not support globally accessible variables due to following reasons:<br />
1)The global variables breaks the referential transparency<br />
2)Global variables creates collisions in namespace.<br />
<br />
<b> 23. What are Encapsulation, Inheritance and Polymorphism?</b><br />
Encapsulation is the mechanism that binds together code and data it manipulates and keeps both safe from outside interference and misuse. Inheritance is the process by which one object acquires the properties of another object. Polymorphism is the feature that allows one interface to be used for general class actions.<br />
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<b> 24. What is the use of bin and lib in JDK?</b><br />
Bin contains all tools such as javac, appletviewer, awt tool, etc., whereas lib contains API and all packages.<br />
<br />
<b> 25. What is method overloading and method overriding?</b><br />
Method overloading: When a method in a class having the same method name with different arguments is said to be method overloading. Method overriding : When a method in a class having the same method name with same arguments is said to be method overriding.<br />
<br />
<b> 26. What is the difference between this() and super()?</b><br />
this() can be used to invoke a constructor of the same class whereas super() can be used to invoke a super class constructor.<br />
<br />
<b> 27. What is Domain Naming Service(DNS)?</b><br />
It is very difficult to remember a set of numbers(IP address) to connect to the Internet. The Domain Naming Service(DNS) is used to overcome this problem. It maps one particular IP address to a string of characters. For example, www. mascom. com implies com is the domain name reserved for US commercial sites, moscom is the name of the company and www is the name of the specific computer, which is mascom’s server.<br />
<br />
<b> 28. What is URL?</b><br />
URL stands for Uniform Resource Locator and it points to resource files on the Internet. URL has four components: http://www. address. com:80/index.html, where http - protocol name, address - IP address or host name, 80 - port number and index.html - file path.<br />
<br />
<b> 29. What is RMI and steps involved in developing an RMI object?</b><br />
Remote Method Invocation (RMI) allows java object that executes on one machine and to invoke the method of a Java object to execute on another machine. The steps involved in developing an RMI object are: a) Define the interfaces b) Implementing these interfaces c) Compile the interfaces and their implementations with the java compiler d) Compile the server implementation with RMI compiler e) Run the RMI registry f) Run the application.<br />
<b><br /></b>
<b>30. What is RMI architecture?</b><br />
RMI architecture consists of four layers and each layer performs specific functions: a) Application layer - contains the actual object definition. b) Proxy layer - consists of stub and skeleton. c) Remote Reference layer - gets the stream of bytes from the transport layer and sends it to the proxy layer. d) Transportation layer - responsible for handling the actual machine-to-machine communication.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com61tag:blogger.com,1999:blog-3432454840355531036.post-70878581651884103802019-04-27T00:01:00.000-07:002019-04-27T00:01:11.999-07:00Viva questions and answers for data structure<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue;">Recently Asked Data Structures Viva Questions and Answers:</span></h3>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhfGg9PBwywDCzVBWM24I_8bqd1e0cbgnTfz9cHaWmeybn5qw1YeCOZrHhM4g4Mlbh_ijShcFvyy8imH6qHjbFWRHD8OJKa6AeWsP2l3qJ2xlSuojhhZxQIzzyZQ_MxDmWZLmuAiDzQ5IBz/s1600/data+structure.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="56" data-original-width="303" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhfGg9PBwywDCzVBWM24I_8bqd1e0cbgnTfz9cHaWmeybn5qw1YeCOZrHhM4g4Mlbh_ijShcFvyy8imH6qHjbFWRHD8OJKa6AeWsP2l3qJ2xlSuojhhZxQIzzyZQ_MxDmWZLmuAiDzQ5IBz/s1600/data+structure.PNG" /></a></div>
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<br />
<b>1. What is data structure?</b><br />
The logical and mathematical model of a particular organization of data is called data structure. There are two types of data structure<br />
1.Linear<br />
2.Nonlinear<br />
<br />
<b>2. What are the goals of Data Structure?</b><br />
It must rich enough in structure to reflect the actual relationship of data in real world.<br />
The structure should be simple enough for efficient processing of data.<br />
<br />
<b>3. What does abstract Data Type Mean?</b><br />
Data type is a collection of values and a set of operations on these values. Abstract data type refer to the mathematical concept that define the data type.It is a useful tool for specifying the logical properties of a data type.ADT consists of two parts<br />
1.Values definition<br />
2.Operation definition<br />
<br />
<b>4. What is the difference between a Stack and an Array?</b><br />
Stack is a ordered collection of items<br />
Stack is a dynamic object whose size is constantly changing as items are pushed and popped .<br />
Stack may contain different data types<br />
Stack is declared as a structure containing an array to hold the element of the stack, and an integer to indicate the current stack top within the array.<br />
<br />
<b>ARRAY</b><br />
Array is an ordered collection of items<br />
Array is a static object i.e. no of item is fixed and is assigned by the declaration of the array<br />
It contains same data types.<br />
Array can be home of a stack i.e. array can be declared large enough for maximum size of the stack.<br />
<br />
<b>5. What do you mean by recursive definition?</b><br />
The definition which defines an object in terms of simpler cases of itself is called recursive definition.<br />
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<b>6. What is sequential search?</b><br />
In sequential search each item in the array is compared with the item being searched until a match occurs. It is applicable to a table organized either as an array or as a linked list.<br />
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<b>7. What actions are performed when a function is called?</b><br />
When a function is called<br />
i) arguments are passed<br />
ii) local variables are allocated and initialized<br />
ii) transferring control to the function<br />
<br />
<b>8. What actions are performed when a function returns?</b><br />
i) Return address is retrieved<br />
ii) Function’s data area is freed<br />
iii) Branch is taken to the return address<br />
<br />
<b>9. What is a linked list?</b><br />
A linked list is a linear collection of data elements, called nodes, where the linear order is given by pointers. Each node has two parts first part contain the information of the element second part contains the address of the next node in the list.<br />
<br />
<b>10. What are the advantages of linked list over array (static data structure)?</b><br />
The disadvantages of array are<br />
unlike linked list it is expensive to insert and delete elements in the array<br />
One can’t double or triple the size of array as it occupies block of memory space.<br />
<br />
In linked list<br />
each element in list contains a field, called a link or pointer which contains the address of the next element<br />
Successive element’s need not occupy adjacent space in memory.<br />
<br />
<b>11. Can we apply binary search algorithm to a sorted linked list, why?</b><br />
No we cannot apply binary search algorithm to a sorted linked list, since there is no way of indexing the middle element in the list. This is the drawback in using linked list as a data structure.<br />
<br />
<b>12. What do you mean by free pool?</b><br />
Pool is a list consisting of unused memory cells which has its own pointer.<br />
<br />
<b>13. What do you mean by garbage collection?</b><br />
It is a technique in which the operating system periodically collects all the deleted space onto the free storage list.It takes place when there is minimum amount of space left in storage list or when "CPU" is ideal.The alternate method to this is to immediately reinsert the space into free storage list which is time consuming.<br />
<br />
<b>14. What do you mean by overflow and underflow?1</b><br />
When new data is to be inserted into the data structure but there is no available space i.e. free storage list is empty this situation is called overflow.<br />
When we want to delete data from a data structure that is empty this situation is called underflow.<br />
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<b>15. What are the disadvantages array implementations of linked list?</b><br />
1.The no of nodes needed can’t be predicted when the program is written.<br />
2.The no of nodes declared must remain allocated throughout its execution<br />
<br />
<b>16. What is a queue?1</b><br />
A queue is an ordered collection of items from which items may be deleted at one end (front end) and items inserted at the other end (rear end).It obeys FIFO rule there is no limit to the number of elements a queue contains.<br />
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<b>17. What is a priority queue?</b><br />
The priority queue is a data structure in which the intrinsic ordering of the elements (numeric or alphabetic)<br />
Determines the result of its basic operation. It is of two types<br />
i) Ascending priority queue- Here smallest item can be removed (insertion is arbitrary)<br />
ii) Descending priority queue- Here largest item can be removed (insertion is arbitrary)<br />
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<b>18. What are the disadvantages of sequential storage?</b><br />
1.Fixed amount of storage remains allocated to the data structure even if it contains less element.<br />
2.No more than fixed amount of storage is allocated causing overflow<br />
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<b>19. What are the disadvantages of representing a stack or queue by a linked list?</b><br />
i) A node in a linked list (info and next field) occupies more storage than a corresponding element in an array.<br />
ii) Additional time spent in managing the available list.<br />
<br />
<b>20. What is dangling pointer and how to avoid it?</b><br />
After a call to free(p) makes a subsequent reference to *p illegal, i.e. though the storage to p is freed but the value of p(address) remain unchanged .so the object at that address may be used as the value of *p (i.e. there is no way to detect the illegality).Here p is called dangling pointer.<br />
To avoid this it is better to set p to NULL after executing free(p).The null pointer value doesn’t reference a storage location it is a pointer that doesn’t point to anything.<br />
<br />
<b>21. What are the disadvantages of linear list?</b><br />
i) We cannot reach any of the nodes that precede node (p)<br />
ii) If a list is traversed, the external pointer to the list must be persevered in order to reference the list again<br />
<br />
<b>22. Define circular list?</b><br />
In linear list the next field of the last node contain a null pointer, when a next field in the last node contain a pointer back to the first node it is called circular list.<br />
Advantages – From any point in the list it is possible to reach at any other point<br />
<b><br /></b><b>23. What are the disadvantages of circular list?</b><br />
i) We can’t traverse the list backward<br />
ii) If a pointer to a node is given we cannot delete the node<br />
<br />
<b>24. Define double linked list?</b><br />
It is a collection of data elements called nodes, where each node is divided into three parts<br />
i) An info field that contains the information stored in the node<br />
ii) Left field that contain pointer to node on left side<br />
iii) Right field that contain pointer to node on right side<br />
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<b>25. Is it necessary to sort a file before searching a particular item ?</b><br />
If less work is involved in searching a element than to sort and then extract, then we don’t go for sort<br />
If frequent use of the file is required for the purpose of retrieving specific element, it is more efficient to sort the file.Thus it depends on situation.<br />
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<b>26. What are the issues that hamper the efficiency in sorting a file?</b><br />
The issues are<br />
i) Length of time required by the programmer in coding a particular sorting program<br />
ii) Amount of machine time necessary for running the particular program<br />
iii)The amount of space necessary for the particular program .<br />
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<b>27. Calculate the efficiency of sequential search?</b><br />
The number of comparisons depends on where the record with the argument key appears in the table<br />
If it appears at first position then one comparison<br />
If it appears at last position then n comparisons<br />
Average=(n+1)/2 comparisons<br />
Unsuccessful search n comparisons<br />
Number of comparisons in any case is O (n).<br />
<br />
<b>28. Is any implicit arguments are passed to a function when it is called?</b><br />
Yes there is a set of implicit arguments that contain information necessary for the function to execute and return correctly. One of them is return address which is stored within the function’s data area, at the time of returning to calling program the address is retrieved and the function branches to that location.<br />
<br />
<b>29. Parenthesis is never required in Postfix or Prefix expressions, why?</b><br />
Parenthesis is not required because the order of the operators in the postfix /prefix expressions determines the actual order of operations in evaluating the expression<br />
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<b>30. List out the areas in which data structures are applied extensively?</b><br />
Compiler Design,<br />
Operating System,<br />
Database Management System,<br />
Statistical analysis package,<br />
Numerical Analysis,<br />
Graphics,<br />
Artificial Intelligence,<br />
Simulation<br />
<br />
<b>31. What are the major data structures used in the following areas : network data model & Hierarchical data model?</b><br />
RDBMS – Array (i.e. Array of structures)<br />
Network data model – Graph<br />
Hierarchical data model – Trees<br />
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<b>32. If you are using C language to implement the heterogeneous linked list, what pointer type will you use?</b><br />
The heterogeneous linked list contains different data types in its nodes and we need a link, pointer to connect them. It is not possible to use ordinary pointers for this. So we go for void pointer. Void pointer is capable of storing pointer to any type as it is a generic pointer type.<br />
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<b>33. Minimum number of queues needed to implement the priority queue?</b><br />
Two. One queue is used for actual storing of data and another for storing priorities.<br />
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<b>34. What is the data structures used to perform recursion?</b><br />
Stack. Because of its LIFO (Last In First Out) property it remembers its ‘caller’ so knows whom to return when the function has to return. Recursion makes use of system stack for storing the return addresses of the function calls.<br />
Every recursive function has its equivalent iterative (non-recursive) function. Even when such equivalent iterative procedures are written, explicit stack is to be used.<br />
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<b>35. What are the notations used in Evaluation of Arithmetic Expressions using prefix and postfix forms?</b><br />
Polish and Reverse Polish notations.<br />
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<b>36. Convert the expression ((A + B) * C – (D – E) ^ (F + G)) to equivalent Prefix and Postfix notations?</b><br />
1.Prefix Notation:<br />
^ – * +ABC – DE + FG<br />
2.Postfix Notation:<br />
AB + C * DE – – FG + ^<br />
<br />
<b>37. Sorting is not possible by using which of the following methods?</b><br />
(a) Insertion<br />
(b) Selection<br />
(c) Exchange<br />
(d) Deletion<br />
(d) Deletion.<br />
Using insertion we can perform insertion sort, using selection we can perform selection sort, using exchange we can perform the bubble sort (and other similar sorting methods). But no sorting method can be done just using deletion.<br />
<br />
<b>38. List out few of the Application of tree data-structure?</b><br />
The manipulation of Arithmetic expression,<br />
Symbol Table construction,<br />
Syntax analysis.<br />
<br />
<b>39. List out few of the applications that make use of Multilinked Structures?</b><br />
Sparse matrix, Index generation.<br />
<br />
<b>40. in tree construction which is the suitable efficient data structure?</b><br />
(A) Array (b) Linked list (c) Stack (d) Queue (e) none<br />
(b) Linked list<br />
<br />
<b>41. What is the type of the algorithm used in solving the 8 Queens problem?</b><br />
Backtracking<br />
<br />
<b>42. In an AVL tree, at what condition the balancing is to be done?</b><br />
If the ‘pivotal value’ (or the ‘Height factor’) is greater than 1 or less than –1.<br />
<br />
<b>43. In RDBMS, what is the efficient data structure used in the internal storage representation?</b><br />
B+ tree. Because in B+ tree, all the data is stored only in leaf nodes, that makes searching easier. This corresponds to the records that shall be stored in leaf nodes.<br />
<br />
<b>45. One of the following tree structures, which is, efficient considering space and time complexities?</b><br />
a) Incomplete Binary Tree.<br />
b) Complete Binary Tree.<br />
c) Full Binary Tree.<br />
b) Complete Binary Tree.<br />
By the method of elimination:<br />
Full binary tree loses its nature when operations of insertions and deletions are done. For incomplete binary trees,<br />
extra property of complete binary tree is maintained even after operations like additions and deletions are done on it.<br />
<br />
<b>46. What is a spanning Tree?</b><br />
A spanning tree is a tree associated with a network. All the nodes of the graph appear on the tree once. A minimum spanning tree is a spanning tree organized so that the total edge weight between nodes is minimized.<br />
<br />
<b>47. Does the minimum spanning tree of a graph give the shortest distance between any 2 specified nodes?</b><br />
No.Minimal spanning tree assures that the total weight of the tree is kept at its minimum. But it doesn’t mean that the distance between any two nodes involved in the minimum-spanning tree is minimum.<br />
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<b>48. Whether Linked List is linear or Non-linear data structure?</b><br />
According to Storage Linked List is a Non-linear one.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-73545503716226123092019-04-26T23:10:00.000-07:002019-04-26T23:10:44.872-07:00Commonly Asked OOPS VIVA Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<b><span style="color: blue;">Hired Oops VIVA Questions and Answers:</span></b></h3>
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<b>1. What is OOPS?</b><br />
OOPS is abbreviated as Object Oriented Programming system in which programs are considered as a collection of objects. Each object is nothing but an instance of a class.<br />
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<b>2. Write basic concepts of OOPS?</b><br />
Following are the concepts of OOPS and are as follows:.<br />
<br />
Abstraction.<br />
Encapsulation.<br />
Inheritance.<br />
Polymorphism.<br />
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<b>3. What is a class?</b><br />
A class is simply a representation of a type of object. It is the blueprint/ plan/ template that describe the details of an object.<br />
<br />
<b>4. What is an object?</b><br />
Object is termed as an instance of a class, and it has its own state, behavior and identity.<br />
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<b>5. What is Encapsulation?</b><br />
Encapsulation is an attribute of an object, and it contains all data which is hidden. That hidden data can be restricted to the members of that class.<br />
<b><br /></b>
<b>6. What is Polymorphism?</b><br />
Polymorphism is nothing butassigning behavior or value in a subclass to something that was already declared in the main class. Simply, polymorphism takes more than one form.<br />
<br />
<b>7. What is Inheritance?</b><br />
Inheritance is a concept where one class shares the structure and behavior defined in another class. Ifinheritance applied on one class is called Single Inheritance, and if it depends on multiple classes, then it is called multiple Inheritance.<br />
<br />
<b>8. What are manipulators?</b><br />
Manipulators are the functions which can be used in conjunction with the insertion (<<) and extraction (>>) operators on an object. Examples are endl and setw.<br />
<br />
<b>9. Define a constructor?</b><br />
Constructor is a method used to initialize the state of an object, and it gets invoked at the time of object creation.<br />
<br />
<b>10. Define Destructor?</b><br />
Destructor is a method which is automatically called when the object ismade ofscope or destroyed. Destructor name is also same asclass name but with the tilde symbol before the name.<br />
<br />
<b>11. What is Inline function?</b><br />
Inline function is a technique used by the compilers and instructs to insert complete body of the function wherever that function is used in the program source code.<br />
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12. What is avirtual function?<br />
Virtual function is a member function ofclass and its functionality can be overridden in its derived class. This function can be implemented by using a keyword called virtual, and it can be given during function declaration.Virtual function can be achieved in C++, and it can be achieved in C Language by using function pointers or pointers to function.<br />
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<b>13. What isfriend function?</b><br />
Friend function is a friend of a class that is allowed to access to Public, private or protected data in that same class. If the function is defined outside the class cannot access such information.<br />
Friend can be declared anywhere in the class declaration, and it cannot be affected by access control keywords like private, public or protected.<br />
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<b>14. What is function overloading?</b><br />
Function overloading is defined as a normal function, but it has the ability to perform different tasks. It allows creation of several methods with the same name which differ from each other by type of input and output of the function.<br />
Example:<br />
void add(int& a, int& b);<br />
void add(double& a, double& b);<br />
void add(struct bob& a, struct bob& b);<br />
<br />
<b>15. What is operator overloading?</b><br />
Operator overloading is a function where different operators are applied and depends on the arguments. Operator,-,* can be used to pass through the function , and it has their own precedence to execute.<br />
<br />
Example:<br />
class complex {<br />
double real, imag;<br />
<br />
public:<br />
complex(double r, double i) :<br />
real(r), imag(i) {}<br />
complex operator+(complex a, complex b);<br />
complex operator*(complex a, complex b);<br />
complex& operator=(complex a, complex b);<br />
}<br />
<br />
a=1.2, b=6<br />
<br />
<b>16. What is an abstract class?</b><br />
An abstract class is a class which cannot be instantiated. Creation of an object is not possible withabstract class , but it can be inherited. An abstract class can be contain members, methods and also Abstract method.<br />
<br />
A method that is declared as abstract and does not have implementation is known as abstract method.<br />
<br />
Syntax:<br />
abstract void show(); //no body and abstract keyword<br />
<br />
<b>17. What is a ternary operator?</b><br />
Ternary operator is said to be an operator which takes three arguments. Arguments and results are of different data types , and it is depends on the function. Ternary operator is also called asconditional operator.<br />
<br />
<b>18. What is the use of finalize method?</b><br />
Finalize method helps to perform cleanup operations on the resources which are not currently used. Finalize method is protected , and it is accessible only through this class or by a derived class.<br />
<br />
<b>19. What are different types of arguments?</b><br />
A parameter is a variable used during the declaration of the function or subroutine and arguments are passed to the function , and it should match with the parameter defined. There are two types of Arguments.<br />
Call by Value – Value passed will get modified only inside the function , and it returns the same value whatever it is passed it into the function.<br />
Call by Reference – Value passed will get modified in both inside and outside the functions and it returns the same or different value.<br />
<br />
<b>20. What is super keyword?</b><br />
Super keyword is used to invoke overridden method which overrides one of its superclass methods. This keyword allows to access overridden methods and also to access hidden members of the super class.It also forwards a call from a constructor to a constructor in the super class.<br />
<br />
<b>21. What is method overriding?</b><br />
Method overriding is a feature that allows sub class to provide implementation of a method that is already defined in the main class. This will overrides the implementation in the superclass by providing the same method name, same parameter and same return type.<br />
<br />
<b>22. What is an interface?</b><br />
An interface is a collection of abstract method. If the class implements an inheritance, and then thereby inherits all the abstract methods of an interface.<br />
<br />
<b>23. What is exception handling?</b><br />
Exception is an event that occurs during the execution of a program. Exceptions can be of any type – Run time exception, Error exceptions. Those exceptions are handled properly through exception handling mechanism like try, catch and throw keywords.<br />
<br />
<b>24. What are tokens?</b><br />
Token is recognized by a compiler and it cannot be broken down into component elements. Keywords, identifiers, constants, string literals and operators are examples of tokens.<br />
Even punctuation characters are also considered as tokens – Brackets, Commas, Braces and Parentheses.<br />
<br />
<b>25. Difference between overloading and overriding?</b><br />
<br />
Overloading is static binding whereas Overriding is dynamic binding. Overloading is nothing but the same method with different arguments , and it may or may not return the same value in the same class itself.<br />
Overriding is the same method names with same arguments and return types associates with the class and its child class.<br />
<br />
<b>26. Difference between class and an object?</b><br />
An object is an instance of a class. Objects hold any information , but classes don’t have any information. Definition of properties and functions can be done at class and can be used by the object.<br />
Class can have sub-classes, and an object doesn’t have sub-objects.<br />
<br />
<b>27. What is an abstraction?</b><br />
Abstraction is a good feature of OOPS , and it shows only the necessary details to the client of an object. Means, it shows only necessary details for an object, not the inner details of an object. Example – When you want to switch On television, it not necessary to show all the functions of TV. Whatever is required to switch on TV will be showed by using abstract class.<br />
<br />
<b>28. What are access modifiers?</b><br />
Access modifiers determine the scope of the method or variables that can be accessed from other various objects or classes. There are 5 types of access modifiers , and they are as follows:.<br />
<br />
Private.<br />
Protected.<br />
Public.<br />
Friend.<br />
Protected Friend.<br />
<br />
<b>29. What is sealed modifiers?</b><br />
Sealed modifiers are the access modifiers where it cannot be inherited by the methods. Sealed modifiers can also be applied to properties, events and methods. This modifier cannot be applied to static members.<br />
<br />
<b>30. How can we call the base method without creating an instance?</b><br />
Yes, it is possible to call the base method without creating an instance. And that method should be,.Static method.Doing inheritance from that class.-Use Base Keyword from derived class.<br />
<br />
<b>31. What is the difference between new and override?</b><br />
The new modifier instructs the compiler to use the new implementation instead of the base class function. Whereas, Override modifier helps to override the base class function.<br />
<br />
<b>32. What are the various types of constructors?</b><br />
There are three various types of constructors , and they are as follows:.<br />
<br />
- Default Constructor – With no parameters.<br />
- Parametric Constructor – With Parameters. Create a new instance of a class and also passing arguments simultaneously.<br />
- Copy Constructor – Which creates a new object as a copy of an existing object.<br />
<br />
<b>33. What is early and late binding?</b><br />
Early binding refers to assignment of values to variables during design time whereas late binding refers to assignment of values to variables during run time.<br />
<br />
<b>34. What is ‘this’ pointer?</b><br />
THIS pointer refers to the current object of a class. THIS keyword is used as a pointer which differentiates between the current object with the global object. Basically, it refers to the current object.<br />
<br />
<b>35. What is the difference between structure and a class?</b><br />
Structure default access type is public , but class access type is private. A structure is used for grouping data whereas class can be used for grouping data and methods.<br />
Structures are exclusively used for dataand it doesn’t require strict validation , but classes are used to encapsulates and inherit data which requires strict validation.<br />
<br />
<b>36. What is the default access modifier in a class?</b><br />
The default access modifier of a class is Private by default.<br />
<br />
<b>37. What is pure virtual function?</b><br />
A pure virtual function is a function which can be overridden in the derived classbut cannot be defined. A virtual function can be declared as Pure by using the operator =0.<br />
<br />
Example -.<br />
Virtual void function1() // Virtual, Not pure<br />
Virtual void function2() = 0 //Pure virtual<br />
<br />
<b>38. What are all the operators that cannot be overloaded?</b><br />
Following are the operators that cannot be overloaded -.<br />
<br />
Scope Resolution (:: )<br />
Member Selection (.)<br />
Member selection through a pointer to function (.*)<br />
<br />
<b>39. What is dynamic or run time polymorphism?</b><br />
Dynamic or Run time polymorphism is also known as method overriding in which call to an overridden function is resolved during run time, not at the compile time. It means having two or more methods with the same name,same signature but with different implementation.<br />
<br />
<b>40. Do we require parameter for constructors?</b><br />
No, we do not require parameter for constructors.<br />
<br />
<b>41. What is a copy constructor?</b><br />
This is a special constructor for creating a new object as a copy of an existing object. There will be always only on copy constructor that can be either defined by the user or the system.<br />
<br />
<b>42. What does the keyword virtual represented in the method definition?</b><br />
It means, we can override the method.<br />
<br />
<b>43. Whether static method can use non static members?</b><br />
False.<br />
<br />
<b>44. What arebase class, sub class and super class?</b><br />
Base class is the most generalized class , and it is said to be a root class.<br />
Sub class is a class that inherits from one or more base classes.<br />
Super class is the parent class from which another class inherits.<br />
<br />
<b>45. What is static and dynamic binding?</b><br />
Binding is nothing but the association of a name with the class. Static binding is a binding in which name can be associated with the class during compilation time , and it is also called as early Binding.<br />
Dynamic binding is a binding in which name can be associated with the class during execution time , and it is also called as Late Binding.<br />
<br />
<b>46. How many instances can be created for an abstract class?</b><br />
Zero instances will be created for an abstract class.<br />
<br />
<b>47. Which keyword can be used for overloading?</b><br />
Operator keyword is used for overloading.<br />
<br />
<b>48. What is the default access specifier in a class definition?</b><br />
Private access specifier is used in a class definition.<br />
<b><br /></b>
<b>49. Which OOPS concept is used as reuse mechanism?</b><br />
Inheritance is the OOPS concept that can be used as reuse mechanism.<br />
<br />
<b>50. Which OOPS concept exposes only necessary information to the calling functions?</b><br />
Data Hiding / Abstraction</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-2107461341541472022019-04-26T22:27:00.000-07:002019-04-26T22:27:07.091-07:0015 TOP Real Time UML Lab Viva Questions Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue;">Recently Asked UML VIVA Questions and Answers:</span></h3>
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<br />
<b>1.What is UML?</b><br />
UML stands for the Unified Modeling Language.<br />
It is a graphical language for 1) visualizing, 2) constructing, and 3) documenting the artifacts of a system.<br />
It allows you to create a blue print of all the aspects of the system, before actually physically implementing the system.<br />
<b><br /></b>
<b>2.What are the advantages of creating a model?</b><br />
Modeling is a proven and well-accepted engineering technique which helps build a model.<br />
Model is a simplification of reality; it is a blueprint of the actual system that needs to be built.<br />
Model helps to visualize the system.<br />
Model helps to specify the structural and behavior of the system.<br />
Model helps make templates for constructing the system.<br />
Model helps document the system.<br />
<b><br /></b>
<b>3.What are the different views that are considered when building an object-oriented software system? </b><br />
Normally there are 5 views.<br />
Use Case view - This view exposes the requirements of a system.<br />
Design View - Capturing the vocabulary.<br />
Process View - modeling the distribution of the systems processes and threads.<br />
Implementation view - addressing the physical implementation of the system.<br />
Deployment view - focus on the modeling the components required for deploying the system.<br />
<br />
<b>4.What are the major three types of modeling used?</b><br />
The 3 Major types of modeling are<br />
architectural,<br />
behavioral, and<br />
structural.<br />
5.Name 9 modeling diagrams that are frequently used?<br />
9 Modeling diagrams that are commonly used are<br />
Use case diagram<br />
Class Diagram<br />
Object Diagram<br />
Sequence Diagram<br />
statechart Diagram<br />
Collaboration Diagram<br />
Activity Diagram<br />
Component diagram<br />
Deployment Diagram.<br />
<br />
<b>6.How would you define Architecture?</b><br />
Architecture is not only taking care of the structural and behavioral aspect of a software system but also taking into account the software usage, functionality, performance, reuse, economic and technology constraints.<br />
<br />
<b>7.What is SDLC (Software Development Life Cycle)?</b><br />
SDLC is a system including processes that are<br />
Use case driven,<br />
Architecture centric,<br />
Iterative, and<br />
Incremental.<br />
<b><br /></b>
<b>8.What is the Life Cycle divided into?</b><br />
This Life cycle is divided into phases.<br />
Each Phase is a time span between two milestones.<br />
The milestones are<br />
Inception,<br />
Elaboration,<br />
Construction, and<br />
Transition.<br />
<br />
<b>9.What are the Process Workflows that evolve through these phases?</b><br />
The Process Workflows that evolve through these phases are<br />
Business Modeling,<br />
Requirement gathering,<br />
Analysis and Design,<br />
Implementation,<br />
Testing,<br />
Deployment.<br />
Supporting Workflows are Configuration, change management, and Project management.<br />
<br />
<b>10.What are Relationships?</b><br />
There are different kinds of relationships:<br />
Dependencies,<br />
Generalization, and<br />
Association.<br />
Dependencies are relationships between two entities.<br />
A change in specification of one thing may affect another thing.<br />
Most commonly it is used to show that one class uses another class as an argument in the signature of the operation.<br />
<br />
Generalization is relationships specified in the class subclass scenario, it is shown when one entity inherits from other.<br />
Associations are structural relationships that are:<br />
a room has walls,<br />
Person works for a company.<br />
<br />
Aggregation is a type of association where there is a has a relationship.<br />
As in the following examples: A room has walls, or if there are two classes room and walls then the relation ship is called a association and further defined as an aggregation.<br />
<br />
<b>11.How are the diagrams divided? </b><br />
The nine diagrams are divided into static diagrams and dynamic diagrams.<br />
<br />
<b> 12.Static Diagrams (Also called Structural Diagram): </b><br />
The following diagrams are static diagrams.<br />
Class diagram,<br />
Object diagram,<br />
Component Diagram,<br />
Deployment diagram.<br />
<br />
<b>13.Dynamic Diagrams (Also called Behavioral Diagrams):</b><br />
The following diagrams are dynamic diagrams.<br />
Use Case Diagram,<br />
Sequence Diagram,<br />
Collaboration Diagram,<br />
Activity diagram,<br />
Statechart diagram.<br />
<br />
<b>14.What are Messages?</b><br />
A message is the specification of a communication, when a message is passed that results in action that is in turn an executable statement.<br />
<br />
<b>15.What is an Use Case?</b><br />
A use case specifies the behavior of a system or a part of a system.<br />
Use cases are used to capture the behavior that need to be developed.<br />
It involves the interaction of actors and the system.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com1tag:blogger.com,1999:blog-3432454840355531036.post-38452930805824231332019-04-22T23:55:00.001-07:002019-04-23T00:07:36.739-07:00Top 40 Network Analysis Lab Viva Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="font-size: 18px;"><span style="color: blue;">Model Viva Questions ForName Of The Lab: Network Analysis:</span></span></h3>
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<br />
<b>1.What is resistance?</b><br />
the resistance is the property of a material to oppose the flow of current in a material.its unit is ohm.<br />
<br />
<b>2.What are the material used for resistor?</b><br />
the material used are maganin (alloy of copper magnese and nickel),constantan(alloy of nickel and<br />
copper).<br />
<br />
<b>3.what is inductance?</b><br />
It is the property of a material by virtue of which it opposes any change of magnitude and direction of<br />
current passing through the conductor.<br />
<br />
<b>4.what happens to voltage when current through the inductor is constant?</b><br />
The voltage across inductor is zero.<br />
<br />
<b>5.how will you define capacitance?</b><br />
It is the ability to store electric charge within it.Capacitance is a measure of charge per unit voltage<br />
that can be stored in an element.<br />
<br />
<b>6.What happens to voltage when current is zero?</b><br />
the voltage is constant.<br />
<br />
<b>7.When we use 3 terminal resistor?</b><br />
It is used when resistance is less than 1 ohm.<br />
<br />
<b>8.what is the unit of charge and current?</b><br />
the units are coulomb and ampere.<br />
<br />
<b>9.What are the properties of a resistor?</b><br />
the properties are high resistivity ,resistance to oxidation, corrosion and moisture.<br />
<br />
<b>10.what is Q factor?</b><br />
the Q factor is ratio of inductive reactance to resistance of a coil.<br />
<br />
<b>11.What are the material used for inductance coil?</b><br />
the materials used are marble because it is unaffected by atmospheric conditions.<br />
<br />
<b>12.Which capacitor is preferred for high voltage and frequency?</b><br />
The vaccum and gas filled capacitor are used for high voltage and frequency applications.<br />
<br />
<b>13.State Kirchoff current law?</b><br />
The algebraic sum of currents at any node of a circuit is zero. The sum of incoming current is equal<br />
to sum of outgoing current.<br />
<br />
<b>14.What are dependent sources?</b><br />
When strength of voltage or current changes in the source for any change in the connected network<br />
they are called dependent sources.<br />
<br />
<b>15.List examples of voltage source?</b><br />
The examples of voltage source are battery and generator.<br />
<br />
<b>16.List examples of current sources?</b><br />
semiconductor devices like transistor and diode are treated as current sources.<br />
<br />
<b>17.state Kirchoff voltage law?</b><br />
Kirchoff voltage law states that the algebraic sum of all branch voltages around any closed loop of a<br />
network is zero at all instant of time.<br />
<br />
<b>18.State TheveninTheorem?</b><br />
This theorem states that any linear network with output terminal AB can be replaced by a single<br />
voltage source V in series with a single impedance.<br />
<br />
<b>19.How equivalent impedance is calculated in TheveninTheorem?</b><br />
All independent voltage sources are short circuited and all independent current sources are open<br />
circuited.<br />
<br />
<b>20.What is the limitation of Kirchoffs law?</b><br />
It fails in distributed parameter network.<br />
<br />
<b>21.State Nortons theorem?</b><br />
This theorem states that any linear bilateral network with active network with output terminals AB<br />
Can be replaced by a single current source in parallel with a single impedance Z..<br />
<b><br /></b>
<b>22.Is the theorem applicable to ac sources?</b><br />
No it is applicable to dc circuits with and without controlled sources.<br />
<br />
<b>23.Define Norton equivalent circuit?</b><br />
The Norton equivalent circuit is a current generator which is placed in parallel to internal resistance.<br />
<br />
<b>24.State Superposition theorem?</b><br />
If a number of voltages or current sources are acting simultaneously in a linear network the resultant<br />
current in any branch is the algebraic sum of current that would be produced in it when each source acts alone replacing all other independent sources by their internal resistances.<br />
<b><br /></b>
<b>25.Sate Maximum power transfer theorem?</b><br />
A resistance load being connected to a dc network receives maximum power when load resistance is<br />
equal to internal resistance.<br />
<br />
<b>26.What is the efficiency during maximum power transfer?</b><br />
50%.<br />
<br />
<b>27.Define branch?</b><br />
It is a part of a network which lies between two junction points.<br />
<br />
<b>28.Define active and passive network?</b><br />
The network which has no current or voltage source is called passive network.<br />
The network which either has current or voltage source is called active network.<br />
<br />
<b>29.State Ohm’s Law?</b><br />
The current through any conductor is directly proportional to the applied potential difference across it<br />
keeping physical condition unchanged.<br />
<br />
<b>30.Define unilateral circuit?</b><br />
A10 The circuit whose properties are not same in either direction is known as unilateral circuit.<br />
<br />
<b>31.Define filter?</b><br />
A filter is an electrical network that can transmit signals within a specified frequency range.<br />
<br />
<b>32.List the characteristics of filter?</b><br />
An ideal filter would transmit signals under the passband frequencies without attenuation and<br />
completely suppress the signal with attenuation band of frequencies with a sharp cutt off profile.<br />
<br />
<b>33.Define characteristics impedance?</b><br />
The characteristics impedance of a filter matches with circuit to which it is connected throughout the<br />
pass band.<br />
<br />
<b>34.What is the unit of attenuation?</b><br />
The unit is decibel and neper.<br />
<br />
<b>35.What are the application of filter?</b><br />
the Filter is used in voice frequency telegraphy,multi channel communication, TV broadcasting and telephony.<br />
<br />
<b>36.Define active filter?</b><br />
The active filter contains components like operational amplifier that introduce some gain in the signal.<br />
<br />
<b>37.List advantges of active filter over passive filter?</b><br />
Active filter eliminate bulky components.It offer gain.It can drive low impedance loads.It is easy to<br />
tune.<br />
<br />
<b>38.List the disadvantages of constant K filters?</b><br />
The attenuation does not increase rapidly beyond cutt off frequency.<br />
characteristics impedance varies widely in the pass band from desired value.<br />
<br />
<b>39.Define cuttoff frequency?</b><br />
The frequency that seperates the pass and attenuation band is known as cutt off frequency.<br />
<br />
<b>40. How a band pass filter is constructed?</b><br />
This filter is a combination of two parallel tuned circuit.This is a special type of LC filter alongwith a<br />
particular BW frequency to be allowed through it. </div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-28527657744756277972019-04-22T03:32:00.001-07:002019-04-22T03:32:12.533-07:00Hired Operating System Viva Questions And Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<br />
<b>1.What is an operating system?</b><br />
An operating system is a program that acts as an intermediary between the user and the computer hardware. The purpose of an OS is to provide a convenient environment in which user can execute programs in a convenient and efficient manner.It is a resource allocator responsible for allocating system resources and a control program which controls the operation of the computer h/w.<br />
<br />
<b>2.What are the various components of a computer system?</b><br />
1. The hardware<br />
2. The operating system<br />
3. The application programs<br />
4. The users.<br />
<br />
<b>3.What is purpose of different operating systems?</b><br />
The machine Purpose Workstation individual usability &Resources utilization Mainframe Optimize utilization of hardware PC Support complex games, business application Hand held PCs Easy interface & min. power consumption<br />
<b><br /></b><b>4.What are the different operating systems?</b><br />
1. Batched operating systems<br />
2. Multi-programmed operating systems<br />
3. timesharing operating systems<br />
4. Distributed operating systems<br />
5. Real-time operating systems<br />
<br />
<b>6.What is a boot-strap program?</b><br />
Bootstrapping is a technique by which a simple computer program activates a more complicated system of programs. It comes from an old expression "to pull oneself up by one's bootstraps."<br />
<br />
<b>7.What is BIOS?</b><br />
A BIOS is software that is put on computers. This allows the user to configure the input and output of a computer. A BIOS is also known as firmware.<br />
<br />
<b>8.Explain the concept of the batched operating systems?</b><br />
In batched operating system the users gives their jobs to the operator who sorts the programs according to their requirements and executes them. This is time consuming but makes the CPU busy all the time.<br />
<br />
<b>9.Explain the concept of the multi-programmed operating systems?</b><br />
A multi-programmed operating systems can execute a number of programs concurrently. The operating system fetches a group of programs from the job-pool in the secondary storage which contains all the programs to be executed, and places them in the main memory. This process is called job scheduling. Then it chooses a program from the ready queue and gives them to CPU to execute. When a executing program needs some I/O operation then the operating system fetches another program and hands it to the CPU for execution, thus keeping the CPU busy all the time.<br />
<br />
<b>10.Explain the concept of the time sharing operating systems?</b><br />
It is a logical extension of the multi-programmed OS where user can interact with the program. The CPU executes multiple jobs by switching among them, but the switches occur so frequently that the user feels as if the operating system is running only his program.<br />
<br />
<b>11.Explain the concept of the multi-processor systems or parallel systems?</b><br />
They contain a no. of processors to increase the speed of execution, and reliability, and economy. They are of two types:<br />
1. Symmetric multiprocessing<br />
2. Asymmetric multiprocessing<br />
In Symmetric multi processing each processor run an identical copy of the OS, and these copies communicate with each other as and when needed.But in Asymmetric multiprocessing each processor is assigned a specific task.<br />
<br />
<b>12.Explain the concept of the Distributed systems?</b><br />
Distributed systems work in a network. They can share the network resources,communicate with each other<br />
<br />
<b>13.Explain the concept of Real-time operating systems?</b><br />
A real time operating system is used when rigid time requirement have been placed on the operation of a processor or the flow of the data; thus, it is often used as a control device in a dedicated application. Here the sensors bring data to the computer. The computer must analyze the data and possibly adjust controls to<br />
modify the sensor input.<br />
They are of two types:<br />
1. Hard real time OS<br />
2. Soft real time OS<br />
Hard-real-time OS has well-defined fixed time constraints. But soft real time operating systems have less stringent timing constraints.<br />
<br />
<b>14.Define MULTICS?</b><br />
MULTICS (Multiplexed information and computing services) operating system was developed from 1965-1970 at Massachusetts institute of technology as a computing utility. Many of the ideas used in MULTICS were subsequently used in UNIX.<br />
<br />
<b>15.What is SCSI?</b><br />
Small computer systems interface.<br />
<br />
<b>16.What is a sector?</b><br />
Smallest addressable portion of a disk.<br />
<br />
<b>17.What is cache-coherency?</b><br />
In a multiprocessor system there exist several caches each may containing a copy of same variable A. Then a change in one cache should immediately be reflected in all other caches this process of maintaining the same value of a data in all the caches s called cache-coherency.<br />
<br />
<b>18.What are residence monitors?</b><br />
Early operating systems were called residence monitors.<br />
<br />
<b>19.What is dual-mode operation?</b><br />
In order to protect the operating systems and the system programs from the malfunctioning programs the two mode operations were evolved:<br />
1. System mode.<br />
2. User mode.<br />
Here the user programs cannot directly interact with the system resources, instead they request the operating system which checks the request and does the required task for the user programs-DOS was written for / intel 8088 and has no dual-mode. Pentium provides dual-mode operation.<br />
<b><br /></b><b>20.What are the operating system components?</b><br />
1. Process management<br />
2. Main memory management<br />
3. File management<br />
4. I/O system management<br />
5. Secondary storage management<br />
6. Networking<br />
7. Protection system<br />
8. Command interpreter system<br />
<br />
<b>21.What are operating system services?</b><br />
1. Program execution<br />
2. I/O operations<br />
3. File system manipulation<br />
4. Communication<br />
5. Error detection<br />
6. Resource allocation<br />
7. Accounting<br />
8. Protection<br />
<br />
<b>22.What are system calls?</b><br />
System calls provide the interface between a process and the operating system. System calls for modern Microsoft windows platforms are part of the win32 API, which is available for all the compilers written for Microsoft windows.<br />
<br />
<b>23.What is a layered approach and what is its advantage?</b><br />
Layered approach is a step towards modularizing of the system, in which the operating system is broken up into a number of layers (or levels), each built on top of lower layer. The bottom layer is the hard ware and the top most is the user interface.The main advantage of the layered approach is modularity. The layers are<br />
selected such that each uses the functions (operations) and services of only lower layer. This approach simplifies the debugging and system verification.<br />
<br />
<b>24.What is micro kernel approach and site its advantages?</b><br />
Micro kernel approach is a step towards modularizing the operating system where all nonessential components from the kernel are removed and implemented as system and user level program, making the kernel smaller.The benefits of the micro kernel approach include the ease of extending the operating system. All new services are added to the user space and consequently do not require modification of the kernel. And as kernel is smaller it is easier to upgrade it. Also this approach provides more security and reliability since most services are running as user processes rather than kernel’s keeping the kernel intact.<br />
<br />
<b>25.What are a virtual machines and site their advantages?</b><br />
<br />
It is the concept by which an operating system can create an illusion that a process has its own processor with its own (virtual) memory.<br />
The operating system implements virtual machine concept by using CPU scheduling and virtual memory.<br />
<br />
1. The basic advantage is it provides robust level of security as each virtual machine is isolated from all other VM. Hence the system resources are completely protected.<br />
2. Another advantage is that system development can be done without disrupting normal operation. System programmers are given their own virtual machine, and as system development is done on the virtual machine instead of on the actual<br />
physical machine.<br />
3. Another advantage of the virtual machine is it solves the compatibility problem.<br />
EX: Java supplied by Sun micro system provides a specification for java virtual machine.<br />
<br />
<b>26.What is a process?</b><br />
A program in execution is called a process. Or it may also be called a unit of work. A process needs some system resources as CPU time, memory, files, and i/o devices to accomplish the task. Each process is represented in the operating system by a process control block or task control block (PCB).Processes are of two types:<br />
1. Operating system processes<br />
2. User processes<br />
<br />
<b>27.What are the states of a process?</b><br />
1. New<br />
2. Running<br />
3. Waiting<br />
4. Ready<br />
5. Terminated<br />
<br />
<b>28.What are various scheduling queues?</b><br />
1. Job queue<br />
2. Ready queue<br />
3. Device queue<br />
<b><br /></b><b>29.What is a job queue?</b><br />
When a process enters the system it is placed in the job queue.<br />
<br />
<b>30.What is a ready queue?</b><br />
The processes that are residing in the main memory and are ready and waiting to execute are kept on a list called the ready queue.<br />
<br />
<b>31.What is a device queue?</b><br />
A list of processes waiting for a particular I/O device is called device queue.<br />
<br />
<b>32.What is a long term scheduler & short term schedulers?</b><br />
Long term schedulers are the job schedulers that select processes from the job queue and load them into memory for execution. The short term schedulers are the CPU schedulers that select a process form the ready queue and allocate the CPU to one of them.<br />
<br />
<b>33.What is context switching?</b><br />
Transferring the control from one process to other process requires saving the state of the old process and loading the saved state for new process. This task is known as context switching.<br />
<br />
<b>34.What are the disadvantages of context switching?</b><br />
Time taken for switching from one process to other is pure over head. Because the system does no useful work while switching. So one of the solutions is to go for threading when ever possible.<br />
<br />
<b>35.What are co-operating processes?</b><br />
The processes which share system resources as data among each other. Also the processes can communicate with each other via interprocess communication facility generally used in distributed systems. The best example is chat program used on the www.<br />
<br />
<b>36.What is a thread?</b><br />
A thread is a program line under execution. Thread sometimes called a light-weight process, is a basic unit of CPU utilization; it comprises a thread id, a program counter, a register set, and a stack.<br />
<br />
<b>37.What are the benefits of multithreaded programming?</b><br />
1. Responsiveness (needn’t to wait for a lengthy process)<br />
2. Resources sharing<br />
3. Economy (Context switching between threads is easy)<br />
4. Utilization of multiprocessor architectures (perfect utilization of the multiple processors).<br />
<br />
<b>38.What are types of threads?</b><br />
1. User thread<br />
2. Kernel thread<br />
User threads are easy to create and use but the disadvantage is that if they perform a blocking system calls the kernel is engaged completely to the single user thread blocking other processes. They are created in user space.Kernel threads are supported directly by the operating system. They are slower to create and manage. Most of the OS like Windows NT, Windows 2000, Solaris2, BeOS, and Tru64 Unix support kernel threading.<br />
<br />
<b>39.Which category the java thread do fall in?</b><br />
Java threads are created and managed by the java virtual machine, they do not easily fall under the category of either user or kernel thread……<br />
<br />
<b>40.What are multithreading models?</b><br />
Many OS provide both kernel threading and user threading. They are called multithreading models. They are of three types:<br />
1. Many-to-one model (many user level thread and one kernel thread).<br />
2. One-to-one model<br />
3. Many-to –many<br />
In the first model only one user can access the kernel thread by not allowing multi-processing. Example: Green threads of Solaris.The second model allows multiple threads to run on parallel processing systems. Creating user thread needs to create corresponding kernel thread (disadvantage).Example: Windows NT, Windows 2000, OS/2.The third model allows the user to create as many threads as necessary and the corresponding kernel threads can run in parallel on a multiprocessor.<br />
Example: Solaris2, IRIX, HP-UX, and Tru64 Unix.<br />
<b><br /></b><b>41.What is a P-thread?</b><br />
P-thread refers to the POSIX standard (IEEE 1003.1c) defining an API for thread creation and synchronization. This is a specification for thread behavior, not an implementation. The windows OS have generally not supported the P-threads.<br />
<br />
<b>42.What are java threads?</b><br />
Java is one of the small number of languages that support at the language level for the creation and management of threads. However, because threads are managed by the java virtual machine (JVM), not by a user-level library or kernel, it is difficult to classify Java threads as either user- or kernel-level.<br />
<br />
<b>43.What is process synchronization?</b><br />
A situation, where several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which the access takes place, is called race condition. To guard against the race condition we need to ensure that only one process at a time can be manipulating<br />
the same data. The technique we use for this is called process synchronization.<br />
<br />
<b>44.What is critical section problem?</b><br />
Critical section is the code segment of a process in which the process may be changing common variables, updating tables, writing a file and so on. Only one process is allowed to go into critical section at any given time (mutually exclusive).The critical section problem is to design a protocol that the processes can use to<br />
co-operate. The three basic requirements of critical section are:<br />
1. Mutual exclusion<br />
2. Progress<br />
3. bounded waiting<br />
Bakery algorithm is one of the solutions to CS problem.<br />
<br />
<b>45.What is a semaphore?</b><br />
It is a synchronization tool used to solve complex critical section problems. A semaphore is an integer variable that, apart from initialization, is accessed only through two standard atomic operations: Wait and Signal.<br />
<br />
<b>46.What is bounded-buffer problem?</b><br />
Here we assume that a pool consists of n buffers, each capable of holding one item. The semaphore provides mutual exclusion for accesses to the buffer pool and is initialized to the value 1.The empty and full semaphores count the number of empty and full buffers, respectively. Empty is initialized to n, and full is initialized to 0.<br />
<br />
<b>47.What is readers-writers problem?</b><br />
Here we divide the processes into two types:<br />
1. Readers (Who want to retrieve the data only)<br />
2. Writers (Who want to retrieve as well as manipulate)<br />
We can provide permission to a number of readers to read same data at same time.But a writer must be exclusively allowed to access. There are two solutions to this problem:<br />
1. No reader will be kept waiting unless a writer has already obtained permission to use the shared object. In other words, no reader should wait for other readers to complete simply because a writer is waiting.<br />
2. Once a writer is ready, that writer performs its write as soon as possible. In other words, if a writer is waiting to access the object, no new may start reading.<br />
<br />
<b>48.What is dining philosophers’ problem?</b><br />
Consider 5 philosophers who spend their lives thinking and eating. The philosophers share a common circular table surrounded by 5 chairs, each belonging to one philosopher. In the center of the table is a bowl of rice, and the table is laid with five single chop sticks. When a philosopher thinks, she doesn’t interact with her colleagues.<br />
From time to time, a philosopher gets hungry and tries to pick up two chop sticks that are closest to her .A philosopher may pick up only one chop stick at a time. Obviously she can’t pick the stick in some others hand. When a hungry philosopher has both her chopsticks at the same time, she eats without releasing her chopsticks. When she is finished eating, she puts down both of her chopsticks and start thinking again.<br />
<br />
<b>49.What is a deadlock?</b><br />
Suppose a process request resources; if the resources are not available at that time the process enters into a wait state. A waiting process may never again change state, because the resources they have requested are held by some other waiting processes. This situation is called deadlock.<br />
<b><br /></b><b>50.What are necessary conditions for dead lock?</b><br />
1. Mutual exclusion (where at least one resource is non-sharable)<br />
2. Hold and wait (where a process hold one resource and waits for other resource)<br />
3. No preemption (where the resources can’t be preempted)<br />
4. circular wait (where p[i] is waiting for p[j] to release a resource. i= 1,2,…n<br />
j=if (i!=n) then i+1<br />
else 1 )</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-21330789958258526152019-04-22T02:53:00.000-07:002019-04-22T02:53:42.655-07:0011 Top Control Systems Lab Viva Questions And Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue; font-size: 18px;">Common Control Systems Comprehensive Viva Questions with Answers:</span></h3>
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<br />
<b>1.What is Order of the system?</b><br />
Order of the system is defined as the order of the differential equation governing the system. Order of the system can be determined from the transfer function of the system. Also the order of the system helps in understanding the number of poles of the transfer function. For nth order system for a particular transfer function contains 'n' number of poles.<br />
<br />
<b>2.What is Time response of the control system?</b><br />
Time response of the control system is defined as the output of the closed loop system as a function of time. Time response of the system can be obtained by solving the differential equations governing the system or time response of the system can also be obtained by transfer function of the system.<br />
<br />
<b>3.How Time response of the system is divided?</b><br />
Answer:Time response of the system consists of two parts: 1.Transient state response 2. Steady state response. Transient response of the system explains about the response of the system when the input changes from one state to the other. Steady state response of the system shows the response as the time t, approaches infinity<br />
<br />
<b>4.What are Test signals and their significance?</b><br />
The knowledge of the input signal is required to predict the response of the system. In most of the systems input signals are not known ahead of the time and it is also difficult to express the input signals mathematically by simple equations. In such cases determining the performance of the system is not possible.Test signals helps in predicting the performance of the system as the input signals which we give are known hence we can see the output response of the system for a given input and can understand the behavior of the control system. The commonly used test signals are impulse, ramp, step signals and sinusoidal signals.<br />
<br />
<b>5.What is Pole of the system?</b><br />
Pole of a function F(s) is the value at which the function F(s) becomes infinite, where F(s) is a function of the complex variable s.<br />
<br />
<b>6.What is Zero of the system?</b><br />
Zero of a function F(s) is a value at which the function F(s) becomes zero, where F(s) is a function of complex variable s.<br />
<br />
<b>7.Electrical Question: What is Signal Flow Graph? </b><br />
A Signal Flow Graph is a diagram that represents a set of simultaneous linear algebraic equations. By taking Laplace transform the time domain differential equations governing a control system can be transferred to a set of algebraic equations in s-domain. The signal Flow graph of the system can be constructed using these equations.<br />
<br />
<b>8.Electrical Question: What is S-domain and its significance?</b><br />
By taking Laplace transform for differential equation in the time domain equations in S-domain can be obtained. L{F(t)}=F(s)<br />
S domain is used for solving the time domain differential equations easily by applying the Laplace for the differential equations.<br />
<br />
<b>9.Electrical Question: What are the basic properties of Signal Flow Graph?</b><br />
The basic properties of the signal flow graph are:<br />
Signal Flow Graphs are applicable to linear systems<br />
It consists of nodes and branches. A node is a point representing a variable or signal. A branch indicates the functional dependence of one signal on another<br />
A node adds the signals of all incoming branches and transmits this sum to all outgoing branches<br />
Signals travel along branches only in a marked direction and is multiplied by the gain of the branch<br />
The algebraic equations must be in the form of cause and effect relationship<br />
<br />
<br />
<b>10.Electrical Question: What is mathematical model of a control system?</b><br />
Control system is a collection of physical elements connected together to serve an objective. The output and input relations of various physical system are governed by differential equations. Mathematical model of a control system constitutes set of differential equations. The response of the output of the system can be studied by solving the differential equations for various input conditions.<br />
<br />
<b>11.Electrical Question: Explain Mechanical Translational System?</b><br />
Model of mechanical translational system can be obtained by using three basic elements Mass, Spring and Dash-pot.<br />
Weight the mechanical system is represented by mass and is assumed to be concentrated at the center of body<br />
The elastic deformation of the body can be represented by the spring<br />
Friction existing in a mechanical system can be represented by dash-pot.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-1119886829027945682019-04-20T05:03:00.002-07:002019-04-20T05:03:42.851-07:00Top Most 75 CAO LAB VIVA Questions And Answers pdf<div dir="ltr" style="text-align: left;" trbidi="on">
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<b>1. What are the types of computer?</b><br />
Personal computer, notebook computer, workstations, enterprise or mainframes.<br />
<br />
<b>2. What are the functional units of a computer?</b><br />
Input unit, memory unit, arithmetic and logic unit, output unit and control unit.<br />
<br />
<b>3. What is a program?</b><br />
A list of instructions that performs a task is called a program. Usually the program is stored in memory.<br />
<br />
<b>4. What is object program?</b><br />
Compiling a high-level language source program in to a list of machine instructions constituting a machine language program is called an object program. It is the assembled machine language program.<br />
<br />
<b>5. What do you mean by bits?</b><br />
Each number, character, or instruction is encoded as a string of binary digits called as bits, each having one of two possible values, 0 or 1.<br />
<br />
<b>6. Define RAM.</b><br />
Memory in which any location can be reached in a short fixed time after specifying its address is called random-access memory (RAM).<br />
<br />
<b>7. Define word length.</b><br />
The number of bits in each word is often referred to as the word length of the computer. Typical word lengths range from 16 to 64 bits.<br />
<br />
<b>8. Define memory access time?</b><br />
The time required to access one word is called as memory access time. This time is fixed and independent of the location of the word being accessed. It typically ranges from a few nanoseconds (ns) to about 100 ns for modern RAM units.<br />
<b><br /></b><b>9. What is memory hierarchy?</b><br />
The memory of a computer is normally implemented as a memory hierarchy of three or four levels of semiconductor RAM units with different speeds and sizes. The small, fast RAM units are called caches. The large and slowest unit is referred to as main memory.<br />
<br />
<b>10. What is primary storage and secondary storage?</b><br />
Primary memory is a fast memory that operates at electronic speeds. It is expensive. Secondary memory is used when large amounts of data and many programs have to be stored, particularly for information that is accessed infrequently.<br />
<br />
<b>11. What are registers?</b><br />
Registers are high speed storage elements. Each register can store one word of data. Access time to registers is faster than access time to the fastest cache memory.<br />
<br />
<b>12. What are timing signals?</b><br />
Timing signals are generated by the control circuits. These are signals that determine when a given action should take place. Data transfers between the processor and memory are also controlled by the control unit through the timing signals.<br />
<br />
<b>13. Explain briefly the operation of Add LOCA, R0.</b><br />
This instruction adds the operand at memory location LOCA to the operand in a register in the processor, R0, and places the sum in to register R0. The original contents of location LOCA are preserved, whereas those of R0 are overwritten.<br />
<br />
<b>14. What is instruction register?</b><br />
The instruction register (IR) holds the instruction that is currently being executed. Its output is available to the control circuits which generate the timing signals that control the various processing elements involved in executing the instruction.<br />
<br />
<b>15. What is program counter?</b><br />
The program counter (PC) keeps track of the execution of a program. It contains the memory address of the next instruction to be fetched and executed.<br />
<br />
<b>16. What is MAR and MDR?</b><br />
The memory address register (MAR) holds the address of the location to be accessed. The memory data register (MDR) contains the data to be written into or read out of the addressed location.<br />
<br />
<b>17. What is an interrupt?</b><br />
An interrupt is a request from an I/O device for service by the processor. The processor provides the requested service by executing an appropriate interrupt-service routine.<br />
<br />
<b>18. Define bus.</b><br />
A group of lines that serves as a connecting path for several devices is called a bus. In addition to the lines that carry data, the bus must have lines for address and control purposes.<br />
<br />
<b>19. What is a compiler?</b><br />
It is a system software program that translates the high-level language program into a suitable machine language program.<br />
<br />
<b>20. What is a text editor?</b><br />
It is a system program used for entering and editing application programs.<br />
<br />
<b>21. What is a file?</b><br />
A file is simply a sequence of alphanumeric characters or binary data that is stored in memory or in secondary storage. A file can be referred by a name chosen by the user.<br />
<br />
<b>22. Define OS.</b><br />
Operating system (OS) is a large program, or a collection of routines, that is used to control the sharing of and interaction among various computer units as they execute application programs.<br />
<br />
<b>23. What is multiprogramming or multitasking?</b><br />
The operating system manages the concurrent execution of several application programs to make the best possible use of computer resources. This pattern of concurrent execution is called multiprogramming or multitasking.<br />
<br />
<b>24. What is elapsed time?</b><br />
It is a measure of performance of the entire computer system. It is affected by the speed of the processor, the disk and the printer.<br />
<br />
<b>25. What is processor time?</b><br />
The sum of the periods during which the processor is active is called the processor time.<br />
<br />
<b>26. What are clock and clock cycles?</b><br />
The timing signals that control the processor circuits are called as clocks. The clock defines regular time intervals called clock cycles.<br />
<br />
<b>27. Give the basic performance equation.</b><br />
T = (N * S)/R<br />
Where, T – performance parameter<br />
N – actual number of instruction executions<br />
S – average number of basic steps needed to execute one machine instruction<br />
R – clock rate in cycles per second.<br />
<br />
<b>28. What is pipelining?</b><br />
The technique of overlapping the execution of successive instruction for substantial improvement in performance is called pipelining.<br />
<br />
<b>29. What is superscalar execution?</b><br />
In this type of execution, multiple functional units are used to create parallel paths through which different instructions can be executed in parallel. so it is possible to start the execution of several instructions in every clock cycle. This mode of operation is called superscalar execution.<br />
<br />
<b>30. What is RISC and CISC?</b><br />
The processors with simple instructions are called as Reduced Instruction Set Computers(RISC). The processors with more complex instructions are called as Complex Instruction Set Computers (CISC).<br />
<b><br /></b><b>31. Define SPEC rating.</b><br />
Running time on the reference computer<br />
SPEC rating = Running time on the computer under test<br />
<br />
<b>32. Define byte addressable memory.</b><br />
Byte locations have addresses 0,1,2….Thus if the word length of the machine is 32 bits, successive words are located at addresses 0,4,8….with each word consisting of 4 bytes. This is called byte addressable memory.<br />
<br />
<b>33. What is big-endian and little-endian?</b><br />
The name big-endian is used when lower byte addresses are used for the more significant bytes (the leftmost bytes) of the word. The name little-endian is used when lower byte addresses are used for the less significant bytes (the rightmost bytes) of the word.<br />
<br />
<b>34. What is aligned address?</b><br />
Words are said to be aligned in memory if they begin at a byte address that is a multiple of the number of bytes in a word.<br />
<br />
<b>35. Explain briefly the operation of ‘load’.</b><br />
The load operation transfers a copy of the contents of a specific memory location to the processor. The memory contents remain unchanged. To start a load operation, the processor sends the address of the<br />
desired location to the memory and requests that its contents be read. The memory reads the data stored at that address and sends them to the processor.<br />
<br />
<b>36. Explain briefly the operation of ‘store’.</b><br />
The store operation transfers an item of information from the processor to a specific memory location, destroying the former contents of that location. The processor sends the address of the desired location to the memory, together with the data to be written into that memory location.<br />
<br />
<b>37. What is register transfer notation?</b><br />
R3 <- [R1] + [R2]<br />
This type of notation is known as register transfer instruction (RTN). The right-hand side of an RTN expression always denotes a value, and the left-hand side is the name of a location where the value is to be placed, overwriting the old contents of that location.<br />
<br />
<b>38. What is a one address instruction?</b><br />
The instruction that contains the memory address of only one operand is called one address instruction.<br />
Eg. Load A, Store A.<br />
<br />
<b>39. What is a two address instruction?</b><br />
The instruction that contains the memory address of two operands is called two byte address instruction.<br />
Eg. Add A,B , Move B,C.<br />
<br />
<b>40. What is a three address instruction?</b><br />
The instruction that contains the memory address of three operands is called three byte address instruction.<br />
Eg. Add A,B,C.<br />
<br />
<b>41. What is a zero address instruction?</b><br />
Instructions in which the locations of all operands are defined implicitly is called zero address instruction. Such instructions are found in machines that store operands in a structure called push down stack.<br />
<br />
<b>42. What is straight line sequencing?</b><br />
To begin executing a program, the address of its first instruction must be placed into PC. Then the processor control circuits use the information in the PC to fetch and execute instructions, one at a time, in the order of increasing addresses. This is called straight line sequencing.<br />
<br />
<b>43. Define conditional branch.</b><br />
A conditional branch instruction causes a branch only if a specified condition is satisfied. If the condition is not satisfied, the PC is incremented in the normal way and next instruction in the sequential address is<br />
fetched and executed.<br />
<br />
<b>44. Define conditional code flags.</b><br />
The processor keeps track of information about the results of various operations for use by subsequent conditional branch instructions. This is done by recording the required information in individual bits called as conditional code flags.<br />
<br />
<b>45. Define conditional code register (OR) status register.</b><br />
The conditional code flags are usually grouped together in a special processor register called conditional code registers or status registers.<br />
<br />
<b>46. What are the four commonly used flags?</b><br />
N (negative) – set to 1 if the result is negative; otherwise, cleared to 0<br />
Z (zero)- set to 1 if the result is 0; otherwise, cleared to 0<br />
V (overflow) – set to 1 if arithmetic overflow occurs; otherwise, cleared to 0<br />
C (carry)- set to 1 if the carry-out results from the operation; otherwise, cleared to 0<br />
<br />
<b>47. What is addressing modes?</b><br />
The different ways in which the location of a operand is specified in an instruction is referred to as addressing modes.<br />
<br />
<b>48. What are the various addressing modes?</b><br />
Register mode, absolute mode, immediate mode, indirect mode, index mode, relative mode, auto increment mode, auto decrement mode.<br />
<br />
<b>49. Define register mode addressing.</b><br />
In register mode addressing the operand is the contents of a process register. The name of the register is given in the instruction.<br />
<br />
<b>50. Define absolute mode addressing.</b><br />
In absolute mode addressing the operand is in a memory location. The address of this location is given explicitly in the instruction. This is also called direct mode addressing.<br />
<br />
<b>51. Define immediate mode addressing.</b><br />
In immediate mode addressing, the operand is given explicitly in the instruction.<br />
Eg. Move #200,R0.<br />
<br />
<b>52. Define indirect mode addressing.</b><br />
In indirect mode addressing the effective address of the operands is the content of a register or memory location whose address appears in the instruction.<br />
Eg: Add (R2),R0.<br />
<b><br /></b><b>53. What is a pointer?</b><br />
The register or memory location that contains the address of an operand is called a pointer.<br />
Eg: A= *B. Here B is a pointer variable.<br />
<br />
<b>54. Define index mode addressing.</b><br />
In index mode addressing, the effective address of the operand is generated by adding a constant value to the register.<br />
EA= X + [Ri].<br />
<br />
<b>55. Define relative mode addressing.</b><br />
In relative mode addressing the effective address is determined by the index mode using the program counter in the place of the general purpose register Ri.<br />
<br />
<b>56. Define Auto increment mode.</b><br />
In this mode the effective address of the operand is the contents of a register specified in the instruction. After accessing the operand, the contents of this register are automatically incremented to point to the next item in a list. It can be written as (Ri)+.<br />
<br />
<b>57. Define Auto decrement mode.</b><br />
In this mode the contents of a register specified in the instruction are first automatically decremented and then used as the effective address of the operand. . It can be written as -(Ri).<br />
<br />
<b>58. What are mnemonics?</b><br />
When writing programs for a specific computer, words such as Move, Add, Increment and Branch are replaced by acronyms such as MOV, ADD, INC and BR. This is called mnemonics.<br />
<br />
<b>59. What is an assembler?</b><br />
Programs written in assembly language can be automatically translated in to a sequence of machine instructions by a program called an assembler.<br />
<br />
<b>60. What is a source program?</b><br />
The user program in its original alphanumeric text format is called a source program.<br />
<br />
<b>61. What are assembler directives?</b><br />
Consider the example SUM EQU 200. This statement does not denote an instruction that will be executed when the object program is run. This will not even appear in the object program. It simply informs the assembler that the name SUM should be replaced by the value 200 wherever it appears in<br />
the program. Such statements are called assembler directives.<br />
<br />
<b>62. What is symbol table?</b><br />
As the assembler scans through a source program, it keeps track of all names and the numeric values that correspond to them in a table called symbol table. Thus, when a name appears a second time, it is replaced with its value from the table.<br />
<br />
<b>63. What is a two pass assembler?</b><br />
During the first pass of the assembler it creates a complete symbol table. At the end of this pass, all the names will be assigned numeric values. The assembler then goes through the source program second time and substitutes values for all names from the symbol table. Such an assembler is called a two-pass assembler.<br />
<br />
<b>64. What is a loader?</b><br />
The assembler stores the object program on a magnetic disk. The object program must be loaded into the memory of the computer before it is executed. For this to happen, another utility program must already be loaded in the memory. This program is called a loader.<br />
<br />
<b>65. What is the use of debugger program?</b><br />
The debugger program enables the user to stop execution of the object program at some points of interest and to examine the contents of various processor registers and memory locations.<br />
<br />
<b>66. What are device interface?</b><br />
The buffer registers DATAIN and DATAOUT and the status flags SIN and SOUT are part of circuitry and they are commonly known as device interface.<br />
<b><br /></b><b>67. Define memory mapped I/O.</b><br />
Many computers use an arrangement called memory mapped I/O in which some memory address values are used to refer to peripheral device buffer registers, such as DATAIN and DATAOUT. This no special instructions are needed to access the contents of these registers.<br />
<br />
<b>68. What is a stack?</b><br />
A stack is a list of data elements, usually words or bytes , with the accessing restriction that elements can be added or removed at one end of the list only. This end is called the top of the stack, and the other end is called the bottom of the stack.<br />
<br />
<b>69. Why is stack called as last-in-first-out?</b><br />
Stack is called as last-in-first-out (LIFO), because the last data item placed on the stack is the first one removed when retrieval begins. The term push is used to describe placing a new item on the stack and pop is used to describe removing the top item from the stack.<br />
<b><br /></b><b>70. What is a stack pointer?</b><br />
Stack pointer (SP) is a processor register that is used to keep track of the address of the element of the stack that is at the top at any given time. It could be one of the general purpose registers or a register dedicated to this function.<br />
<b><br /></b><b>71. What is a queue?</b><br />
Queue is a data structure similar to the stack. Here new data are added at the back (high address end) and retrieved from the front (low address end) of the queue. Queue is also called as first-in-first-out (FIFO).</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-22249876409973366432019-04-20T04:52:00.005-07:002019-04-20T04:52:57.751-07:00Hired Electrical Measurements Lab Viva Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="color: blue;">electrical measurements viva questions with Answers</span></h3>
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<br />
<b>1 what is measurement? </b><br />
The process of determining the amount, degree, or capacity by comparison (direct or indirect) with the accepted standards of the system units being used.<br />
<br />
<b>2 what is accuracy of a measurement? </b><br />
The degree of exactness (closeness) of a measurement compared to the expected (desired) value.<br />
<br />
<b>3 what is Resolution of a measurement? </b><br />
The smallest change in a measured variable to which an instrument will respond.<br />
<br />
<b>4 what is precision of a measurement? </b><br />
A measure of the consistency or repeatability of measurement, i.e. successive reading do not differ.<br />
<br />
<b>5 what is Sensitivity of a measurement? </b><br />
The ratio of the change in output (response) of the instrument to a change of input or measured<br />
variable.<br />
<br />
<b>6 what is Error of a measurement?</b><br />
The deviation of the change in output (response) of the instrument to a change of input or measured<br />
variable.<br />
<br />
<b>7 what are the three major categories of error? </b><br />
Error may arise from different sources and are usually classified as<br />
1 Gross error 2. Systematic error 3. Random error<br />
<br />
<b>8 what is gross error? </b><br />
These errors are mainly due to human mistakes in reading or in using instruments or error in recording observations. This error also occurs due to incorrect adjustment of instruments and computational mistakes these errors can not treat mathematically.<br />
<br />
<b>9 what is Systematic error? </b><br />
These error occur due1. Instrumental error 2. Environmental error 3. Observational error<br />
<br />
<b>10 what is instrumental error? </b><br />
The instrumental errors arise due to three main reasons:<br />
1. Due to inherent shortcoming in the instrument<br />
2. Due to misuse of the instruments<br />
3. Due to loading effect of instrument<br />
<br />
<b>11.what is Cathode ray oscilloscope (CRO)? </b><br />
Cathode ray oscilloscope is a instrument used for display, measurement and analysis of<br />
waveforms and other phenomenon in electrical and electronic circuit<br />
<br />
12.what are the basic component of a CRO?<br />
CRO Circuit consists of following components:<br />
1. Vertical deflection system 2. Horizontal deflection system 3.Synchronization circuit<br />
4. Blanking circuit 5 Intensity modulation 6position control<br />
7. Focus control 8. Cathode ray tube 9. Calibration circuit<br />
<br />
<b>13.what is the function of probe in CRO? </b><br />
The probe performs the very important function of connecting the test circuit to oscilloscope<br />
without altering, loading or otherwise disturbing the test circuit.<br />
<br />
<b>14 how many types of probe used in CRO? </b><br />
There are three types of probe used in CRO:<br />
1 Direct probe 2. Isolation probe 3. Detector probe<br />
<br />
<b>15.what are the functions of different probes used in CRO?</b><br />
Direct Probe: direct probe avoids stay-pick up which may create problems when low level signals<br />
are being measured. It is used for low freuency or low impedance circuit.<br />
Isolation probe: Isolation probe is used in order to avoid the undesirable circuit loading effects of the shielded probe.<br />
Detector probe: when analyzing the response to modulated signals used in Communications equipment like AM, FM and TV receivers, the detector probe functions to separate the low frequency modulation component from the high freuency carrier.<br />
<br />
<b>16.what is the function of Attenuator in CRO? </b><br />
The voltage in input terminal of the vertical amplifier causes the beam to deflect off the CRT<br />
screen, is unite low in amplitude. So that high amplitude signals may be displayed, an attenuator<br />
network is placed between the vertical input terminals of the vertical amplifier. The main function of the attenuator is to reduce the amplitude of the vertical input signal before applying it to vertical amplifier.<br />
<br />
<b>17.which device is used for the source of emission of electrons in a CRT? </b><br />
A barium and strontium oxide coated cathode is used for the source of emission of electrons in a<br />
CRT.<br />
<br />
<b>18.what is the function of Auadag in a CRO? </b><br />
Ans: An Audage is used in a CRO to collect secondary emission electrons.<br />
<br />
<b>19.what is the function of electron gun assembly used in CRT? </b><br />
The electron gun assembly produces a sharply focused beam of electrons which are accelerated .<br />
to high velocity .this focused beam of electrons strikes the fluorescent screen with sufficient energy to cause a luminous spot on the screen.<br />
<br />
<b>20 what is the function of electron gun used in CRT? </b><br />
The source of focused and accelerated electrons beam is the electron gun. The electron gun<br />
emits electrons and forms them into a beam consist of a heater, a cathode, a grid, a pre-accelerating anode, a focusing anode and an accelerating anode.<br />
<br />
<b>21.What do you mean by an instrument transformer?</b><br />
transformer which is used with measuring instrument is called instrument transformers.<br />
Instrument transformer is used as a protection circuit of power system for the operation of over current, under voltage, Earth fault etc.<br />
<br />
<b>22.what are the types of instrument transformer?</b><br />
there are two types of instrument transformer:<br />
1. Current transformer 2. Voltage transformer<br />
<br />
<b>23.What do you mean by a Current transformer? </b><br />
The transformers which are used for measurement of current is called current transformer.<br />
<br />
<b>24.what do you mean by a Voltage transformer? </b><br />
The transformers used for voltage measurement are called voltage or potential transformer.<br />
<br />
<b>25.what are the Advantages of instrument transformer? </b><br />
Advantages of instrument transformer are:<br />
1. Instrument transformers are moderate in size and used for 5A current and 100 to 200 V<br />
measurement.<br />
2. Instruments using instrument transformer are low cost.<br />
3. Replacement of damage parts is Easy.<br />
4. The metering circuit is isolated the high voltage power circuit hence insulation and safty is<br />
assured for operation.<br />
5. There is low power consumption in metering circuit.<br />
<br />
<b>26.what do you mean by a phase Angel of instrument transformer? </b><br />
The angle between secondary current and primary current of a current transformer is called phase angle of instrument transformer.<br />
<b><br /></b><b>27.what do you mean by transformation ratio of instrument transformer? </b><br />
It is the ratio of primary winding current to the secondary winding current of an instrument<br />
transformer.<br />
<br />
<b>28.what do you mean by Nominal ratio of instrument transformer?</b><br />
It is the ratio of rated primary winding current to the rated secondary winding current of an<br />
instrument transformer.<br />
<br />
<b>29.what do you mean by Turns ratio of instrument transformer? </b><br />
It is the ratio of number of turns in secondary winding to the number of turns in primary winding of an instrument transformer.<br />
<br />
<b>30.what do you mean by ratio correction factor of instrument transformer?</b><br />
It is the ratio of the transformation ratio to the nominal ratio of an instrument transformer </div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-72625763093798771222019-04-19T03:27:00.000-07:002019-04-19T03:38:30.278-07:00TOP 20+ CAD LAB VIVA QUESTIONS AND ANSWERS<div dir="ltr" style="text-align: left;" trbidi="on">
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<b><span style="color: blue;">Computer Aided Design and drafting VIVA Questions and Answers:</span></b></h3>
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<br />
<b>1. What is meant by AutoCAD?</b><br />
AutoCAD is one of the cad system software introduced in dec1982 by Autodesk ltd in Sausallia,<br />
California of USA. It has hit the technical world like shock wave revolutionizing the manner of<br />
drawing preparation.<br />
<br />
<b>2. What is the diff between CAD & CADD?</b><br />
CAD-computer aided design<br />
CADD-computer aided design and drafting<br />
<b><br /></b>
<b>3. What are the applications of CAD? </b><br />
<br />
Product Drawings<br />
Drawings of Operation Cards<br />
Solid Modelling<br />
Design of Forging and Trimming Dies<br />
Design of Tooling, Equipment and Gages.<br />
<br />
<b>4. Define absolute co-ordinates? </b><br />
Design of machine elements, CNC machine tools, robotics etc<br />
Panel design and circuit layout<br />
Mapping ,building plans, contour plotting and structural drawing<br />
Interior design and modeling<br />
from rejinpaul.com<br />
Values locating a point in space that describe its displacement from origin (0,0,0)point of the<br />
drawing.<br />
<br />
<b>5. Define polar co ordinates.</b><br />
Values are locating a point in space that describes its location relative to the last point picked as defined by an angle and s distance.<br />
<br />
<b>6. Define angular dimension? </b><br />
A dimension that measures the angle between two lines or the angle inscribed by an arc segment.<br />
<br />
<b>7. Define aligned dimension? </b><br />
A linear dimension measuring the distance between two points. The dimension line for an aligned dimension is parallel to a line between points.<br />
<br />
<b>8. What is Bylayer? </b><br />
A value that can be assigned to colours and line types so that objects receive their colour and line type properties according to the layer they are on.<br />
<br />
<b>9. What is command line?</b><br />
A text window at the bottom of the screen that’s displays command: prompt. This is where you see what you are entering through the keyboard. Also called the command window.<br />
<br />
<b>10. What is command: prompt: </b><br />
A prompt at the command line, when no commands are currently running.<br />
<br />
<b>11. What is cross hair cursor?</b><br />
A form of the cursor that consists of a horizontal line and a vertical line intersecting at their midpoints, resembling the crosshair in a sighting device.<br />
<br />
<b>12. Define current UCS? </b><br />
A group of settings and values that control the appreance of dimensions.<br />
from rejinpaul.com<br />
The user co-ordinate system that is active in a drawing. It determines the positive X,Y and Z<br />
direction.<br />
<br />
<b>13. What is. dwg? </b><br />
The file extension and format for the standard AUTOcad drawing.<br />
<br />
<b>14. Define graphics window? </b><br />
The appearance of your screen when AUTOcad is running. It consists of the drawing area and surrounding toolbars, menu bars the command window and the status bar.<br />
<b><br /></b>
<b>15. Define line type? </b><br />
The style of appearance of a line. AUTOcad styles include continues, dashed, dash dot. And so on.<br />
<br />
<b>16. What is a hatch patterns? </b><br />
A pattern of lines dots and other shapes that fills in a closed area.<br />
<br />
<b>17. Define MIRROR? </b><br />
A command that makes a copy of selected objects and flips the copy around a specified line to produce a reciprocal image of those objects.<br />
<br />
<b>18. What is an ortho mode? </b><br />
An on/off setting that, when on forces lines to be drawn and objects to be moved in a horizontal or vertical direction only.<br />
<br />
<b>19. What are the advantages of CAD?</b><br />
Greater productivity of the designer, improvement of design quality Easier design, calculation and analysis, quicker rate producing drawings, more accuracy of drawings, colour graphics is possible<br />
<br />
<b>20. What is an object snap mode? </b><br />
Any of a set of tools precisely picking strategic points on an object, including end point, midpoint, center, and so on. It is casually called osnap.<br />
<br />
<b>21. Define block?</b><br />
The description of an association of Auto "CAD" objects that is stored with the drawing file and include a name, an insertion point, and a listening of objects in the association.<br />
<b><br /></b>
<b>22. Define relative co-ordinates? </b><br />
Values are locating a point in space that describes its displacement from last point picked in the drawing rather than from the origin.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-64567178116949084292019-04-19T03:20:00.002-07:002019-04-19T03:47:07.617-07:00Top 45 Computer graphics lab viva questions with answers pdf<div dir="ltr" style="text-align: left;" trbidi="on">
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COMPUTER GRAPHICS: Some Important viva Questions and Answers</h3>
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<b>1. What is scan conversion?</b><br />
A major task of the display processor is digitizing a picture definition given in an application program into a set of pixel-intensity values for storage in the frame buffer. This digitization process is called scan conversion.<br />
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<b>2. Write the properties of video display devices?</b><br />
Properties of video display devices are persistence,resolution, and aspect ratio.<br />
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<b>3. What is rasterization?</b><br />
The process of determining the appropriate pixels for representing picture or graphics object is known as rasterization.<br />
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<b>4. Define Computer graphics.</b><br />
Computer graphics remains one of the most existing andrapidly growing computer fields. Computer graphics maybe defined as a pictorial representation or graphicalrepresentation of objects in a computer.<br />
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<b>5. Name any four input devices?</b><br />
Four input devices are keyboard, mouse, image scanners,and trackball.<br />
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<b>6. Write the two techniques for producing color displays with a CRT?</b><br />
Beam penetration method, shadow mask method.<br />
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<b>7. What is vertical retrace of the electron beam?</b><br />
In raster scan display, at the end of one frame, the electron beam returns to the left top corner of the screen to start the next frame.<br />
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<b>8. Short notes on video controller?</b><br />
Video controller is used to control the operation of the display device. A fixed area of the system is reserved for the frame buffer, and the video controller is given direct access to the frame buffer memory.<br />
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<b>9. What is bitmap?</b><br />
Some system has only one bit per pixel; the frame buffer is often referred to as bitmap.<br />
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<b>10. Differentiate plasma panel display and thin film electro luminescent display?</b><br />
In plasma panel display, the region between two glass plates is filled with neon gas. In thin film electro luminescent display, the region between two glasses plates are filled with phosphor, such as zinc sulphide doped with manganese.<br />
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<b>11. What is resolution?</b><br />
The maximum number of points that can be displayed without overlap on a CRT is referred to as the resolution.<br />
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<b>12. What is horizontal retrace of the electron beam?</b><br />
In raster scan display, the electron beam return to the left of the screen after refreshing each scan line, is called horizontal retrace of the electron beam.<br />
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<b>13. What is filament?</b><br />
In the CRT, heat is applied to the cathode by directing a current through a coil of wire, is called filament.<br />
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<b>14. What is pixel map?</b><br />
Some system has multiple bits per pixel, the frame buffer is often referred to as pixel map.<br />
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<b>15. Write the types of clipping?</b><br />
Point clipping, line clipping, area clipping, text clipping and curve clipping.<br />
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<b>16. What is meant by scan code?</b><br />
When a key is pressed on the keyboard, the keyboard controller places a code carry to the key pressed into a part of the memory called as the keyboard buffer. This code is called as the scan code.<br />
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<b>17. List out the merits and demerits of Penetration techniques?</b><br />
The merits and demerits of the Penetration techniques areas follows. It is an inexpensive technique. It has only four colors. The quality of the picture is not good when it is compared to other techniques. It can display color scans in monitors. Poor limitation etc.<br />
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<b>18. List out the merits and demerits of DVST?</b><br />
The merits and demerits of direct view storage tubes[DVST] are as follows. It has a flat screen. Refreshing of screen is not required. Selective or part erasing of screen is not possible. It has poor contrast Performance is inferior to the refresh CRT.<br />
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<b>19. What do you mean by emissive and non-emissivedisplays?</b><br />
The emissive display converts electrical energy into lightenergy. The plasma panels, thin film electro-luminescent displays are the examples.The Non-emissive are optical effects to convert the sunlightor light from any other source to graphic form. Liquid crystal display is an example<br />
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<b>20. List out the merits and demerits of Plasma paneldisplay?</b><br />
Merits. Refreshing is not required. Produce a very steady image free of Flicker. Less bulky than a CRT.Demerits. Poor resolution of up to 60 d.p.i. It requires complex addressing and wiring. It is costlier than CRT.<br />
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<b>21. What is persistence?</b><br />
The time it takes the emitted light from the screen to decay one tenth of its original intensity is called as persistence.<br />
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<b>22. What is Aspect ratio?</b><br />
The ratio of vertical points to the horizontal points necessary to produce length of lines in both directions of the screen is called the Aspect ratio. Usually the aspect ratio is ¾.<br />
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<b>23. What is the difference between impact and non-impactprinters?</b><br />
Impact printer press formed character faces against an inked ribbon on to the paper. A line printer and dot-matrix printer are examples.Non-impact printer and plotters use Laser techniques,inkjet sprays, Xerographic process, electrostatic method sand electrothermal methods to get images onto the papers. Examples are: Inkjet/Laser printers.<br />
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<b>24. Define pixel?</b><br />
Pixel is shortened forms of picture element. Each screen point is referred to as pixel or pixel.<br />
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<b>25. What is frame buffer?</b><br />
Picture definition is stored in a memory area called frame buffer or refresh buffer.<br />
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<b>26. Where the video controller is used?</b><br />
A special purpose processor, which is used to control the operation of the display device, is known as video controller or display controller.<br />
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<b>27. What is run length encoding?</b><br />
Run length encoding is a compression technique used to store the intensity values in the frame buffer, which store search scan line as a set of integer pairs. One number each pair indicates an intensity value, and second number specifies the number of adjacent pixels on the scan line that are to have that intensity value.<br />
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<b>28. What is point in the computer graphics system?</b><br />
The point is a most basic graphical element & is completely defined by a pair of user coordinates (x, y).<br />
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<b>29. Write short notes on lines?</b><br />
A line is of infinite extent can be defined by an angle of slope q and one point on the line P=P(x,y). This can also be defined as y=mx+C where C is the Y intercept.<br />
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<b>30. Define Circle?</b><br />
Circle is defined by its center xc, yc and its radius in user coordinate units. The equation of the circle is (x-xc) + (yyc)= r2.<br />
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<b>31. What are the various attributes of a line?</b><br />
The line type, width and color are the attributes of the line.The line type include solid line, dashed lines, and dotted lines.<br />
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<b>32. What is anti aliasing?</b><br />
The process of adjusting intensities of the pixels along the line to minimize the effect of aliasing is called anti aliasing.<br />
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<b>33. What is Transformation?</b><br />
Transformation is the process of introducing changes in the shape size and orientation of the object using scaling rotation reflection shearing & translation etc.<br />
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<b>34. What is translation?</b><br />
Translation is the process of changing the position of an object in a straight-line path from one coordinate location to another. Every point (x , y) in the object must under go a displacement to (x|,y|). the transformation is:x| = x + tx ; y| = y+ty<br />
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<b>35. What is rotation?</b><br />
A 2-D rotation is done by re positioning the coordinates along a circular path, in the x-y plane by making an angle with the axes. The transformation is given by:X| = r cos (q + f) and Y| = r sin (q + f).<br />
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<b>36. What is scaling?</b><br />
A 2-D rotation is done by re positioning the coordinates along a circular path, in the x-y plane by making an angle with the axes. The transformation is given by:X| = r cos (q + f) and Y| = r sin (q + f).<br />
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<b>37. What is shearing?</b><br />
The shearing transformation actually slants the object along the X direction or the Y direction as required. ie; this transformation slants the shape of an object along a required plane.<br />
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<b>38. What is reflection?</b><br />
The reflection is actually the transformation that produces a mirror image of an object. For this use some angles and lines of reflection.<br />
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<b>39. What are the two classifications of shear transformation?</b><br />
X shear, y shear<br />
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<b>40. A point (4,3) is rotated counterclockwise by an angle of 45°. Find the rotation matrix and the resultant </b><br />
point<br />
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<b>41. Name any three font editing tools.</b><br />
ResEdit, FONTo grapher<br />
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<b>42. Differentiate serif and sans serif fonts.</b><br />
Give one example Serif fonts has a little decoration at the end of the letter,but serif font has not. Times, new century schoolbook is the examples of serif fonts. Arial, optima are examples for sanserif fonts.<br />
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<b>43. Distinguish between window port & view port?</b><br />
A portion of a picture that is to be displayed by a window is known as window port. The display area of the part selected or the form in which the selected part is viewed is known as view port.<br />
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<b>44. Define clipping?</b><br />
Clipping is the method of cutting a graphics display to neatly fit a predefined graphics region or the view port.<br />
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<b>45. What is the need of homogeneous coordinates?</b><br />
To perform more than one transformation at a time, use homogeneous coordinates or matrixes. They reduce unwanted calculations intermediate steps saves time and memory and produce a sequence of transformations.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com1tag:blogger.com,1999:blog-3432454840355531036.post-39519762937442277382019-04-18T01:59:00.000-07:002019-04-18T01:59:14.263-07:00The 2 Best Answers for “Tell Me About Yourself” (Interview Question)<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="background-color: white; font-family: "arial" , sans-serif; font-size: 16px;"><b><span style="color: blue;">How do you introduce yourself in an interview?</span></b></span></h3>
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1.Good morning to every one present this hall, I have a great pleasure to introduce myself.<br />
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I am Deepak arora, I belongs to Uttrakhand.<br />
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Currently I am pursuing CCNA from network bulls from Gurgaon. I have completed my BCA from INSTITUTE OF MANAGEMENT AND TECHNOLOGY in the year of 2013 with 65%, I had done my 10th and 12th career from Udai raj hindu inter college.<br />
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Now I willing introduce my wonderful family which is presented by god blesses. My family consist of 4 members, My father is business person, my mother is domestic worker and my elder sister got married.<br />
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My quick destination is to be placed in good company like yours. And my final destination is to be carry through a good position.<br />
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My strength is positive attitude and weakness is whenever I didn't complete my work with in time then I am not feeling comfortable. I also like to take new challenges in life, and I strongly believe that these continuous.<br />
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Efforts will make me to produce better results. And I am not so fluent in English but I am working on it. I love to listen music.<br />
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That's all about me.<br />
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Thanking you for wonderful opportunity.<br />
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2.Thank you for giving me a chance to introduce myself,<br />
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I am Dawn, an independent and self supporting person, I am a working student since high school until I finished my College years. I came from a broken family, I grew up with my grandparents, I have 2 sisters the younger one and the elder one, they are also self supporting like me, we are hoping that sooner or later we both become successful and professionals.<br />
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My hobby is listening music and browsing net, I like to browse and reading everything that can help to enhance my knowledge and skills, I also like to study by myself through the net, I am not that fluent in English but I am working on it.<br />
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My strength is when I did simple things and appreciated much by someone. (very heart warming). I am also punctual, I hate absences, I also hate late's, and my weakness is my failure, I don't want to be failed, although everyone knows nobody is perfect but still I don't want to be failed, I don't want anyone getting mad or disappointed because of my failure, another weakness is I can't say no to anyone I easily trust anyone but still I am controlling myself. My aim is to get placed at the reputed company like this.<br />
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That's all thank you :).</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-85217782082064372602019-04-18T01:35:00.001-07:002019-04-18T01:35:38.030-07:00How To Answer "What Are Your Strengths And Weaknesses?<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="background-color: white; font-family: Georgia, Times, "Times New Roman", "Hiragino Kaku Gothic Pro", Meiryo, serif; font-size: 23px;"><span style="color: blue;">What are your strengths and weaknesses? While HR asking interview question?</span></span></h3>
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<b><br /></b><b>1.Shijin said: </b><br />
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Strengths:<br />
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1) Hard work.<br />
2) Positive attitude and thinking.<br />
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Weakness:<br />
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1) Tension.<br />
2) Self confident.<br />
<b><br /></b><b>2.Kristen said: </b><br />
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STRENGTHS:<br />
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1. I am a self motivator.<br />
2. Ambitious.<br />
3. Loyal.<br />
4. Structured.<br />
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WEAKNESSES:<br />
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1. Inability to say no.<br />
2. Over emotional.<br />
3. Over trusting.<br />
4. And, although my strength is that I am structured, I can be too structured and therefore not enough laid back.<br />
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<b>3.Sekhar said: </b><br />
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Strength:<br />
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1. I have a good communication skills and leadership qualities. I got my confidence from my experiences like I was able to manage the 1000 members with different mind sets in my tech fest as an organizer.<br />
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2. I can handle my self in difficult situations, can motivate the others.<br />
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3. I am punctual and very enthusiastic to learn new things.<br />
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4. I have a good quality of being positive, I can enjoy the comments (on me) and can make my surroundings happy with my sense of humour.<br />
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Weaknesses:<br />
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1. I don't like the people, who are telling only good qualities about me.<br />
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2. I can't say no to anyone.<br />
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3. Taking over responsibilities.<br />
<b><br /></b><b>4. Shilpa said: </b><br />
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Strengths:<br />
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First of all, I am a hard worker.<br />
I Can take good decision at any type of situations.<br />
Time manager.<br />
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Weakness:<br />
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I am straight forward. Some time some people don't like this behavior.<br />
I am not comfortable without finish my work.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com3tag:blogger.com,1999:blog-3432454840355531036.post-71392028126397474632019-04-17T02:09:00.000-07:002019-04-17T02:09:52.271-07:00Top 14 Fluid Mechanics VIVA Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<b><span style="color: blue;">Latest Fluid Mechanics VIVA Questions and Answers:</span></b></h3>
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<b>1. How Cavitation can be eliminated in a Pump?</b><br />
Cavitation means bubbles are forming in the liquid.<br />
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To avoid Cavitation, we have to increase the Pump size to One or Two Inch;<br />
To increase the pressure of the Suction Head, or<br />
Decrease the Pump Speed.<br />
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<b>2. Which pump is more efficient Centrifugal pump or Reciprocating pump?</b><br />
Centrifugal pump.<br />
Because flow rate is higher compared to reciprocating pump. Flow is smooth and it requires less space to install. Lower initial cost and lower maintenance cost.<br />
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<b>3. Why Centrifugal Pump is not called as a Positive Displacement Type of Pump?</b><br />
The centrifugal has varying flow depending on pressure or head, whereas the Positive Displacement pump has more or less constant flow regardless of pressure.<br />
Likewise viscosity is constant for positive displacement pump where centrifugal pump have up and down value because the higher viscosity liquids fill the clearances of the pump causing a higher volumetric efficiency. When there is a viscosity change in supply there is also greater loss in the system. This means change in pump flow affected by the pressure change.<br />
One more example is, positive displacement pump has more or less constant efficiency, where centrifugal pump has varying efficiency rate.<br />
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<b>4. Why the centrifugal pump is called high discharge pump?</b><br />
Centrifugal pump is a kinetic device. The centrifugal pump uses the centrifugal force to push out the fluid. So the liquid entering the pump receives kinetic energy from the rotating impeller. The centrifugal action of the impeller accelerates the liquid to a high velocity, transferring mechanical (rotational) energy to the liquid. So it discharges the liquid in high rate. It is given in the following formulae:<br />
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Centrifugal force F= (M*V2)/R.<br />
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Where,<br />
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M-Mass<br />
V-Velocity<br />
R-Radius<br />
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<b>5. Why cavitation will occur in Centrifugal Pumps and not in Displacement pumps?</b><br />
The formation of cavities (or bubbles) is induced by flow separation, or non-uniform flow velocities, inside a pump casing. In centrifugal pumps the eye of the pump impeller is smaller than the flow area of pipe. This decrease in flow area of pump results in increase in flow rate. So pressure drop happened between pump suction and the vanes of the impeller. Here air bubbles or cavities are formed because of liquid vapour due to increase in temperature in impeller. This air bubbles are transmitted to pump which forms cavitation.<br />
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<b>6.What is a radial-flow turbine?</b><br />
In a radial-flow turbine, steam flows outward from the shaft to the casing. The unit is usually a reaction unit, having both fixed and moving blades.<br />
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<b>7.What are four types of turbine seals?</b><br />
Carbon rings fitted in segments around the shaft and held together by garter or retainer springs.<br />
Labyrinth mated with shaft serration’s or shaft seal strips.<br />
Water seals where a shaft runner acts as a pump to create a ring of water around the shaft. Use only treated water to avoid shaft pitting.<br />
Stuffing box using woven or soft packing rings that are compressed with a gland to prevent leakage along the shaft.<br />
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<b>8.What is the function of a thrust bearing?</b><br />
Thrust bearings keep the rotor in its correct axial position.<br />
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<b>9.What are some conditions that may prevent a turbine from developing full power?</b><br />
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The machine is overloaded.<br />
The initial steam pressure and temperature are not up to design conditions.<br />
The exhaust pressure is too high.<br />
The governor is set too low.<br />
The steam strainer is clogged.<br />
Turbine nozzles are clogged with deposits.<br />
Internal wear on nozzles and blades.<br />
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<b>10.What is a stage in a steam turbine?</b><br />
In an impulse turbine, the stage is a set of moving blades behind the nozzle. In a reaction turbine, each row of blades is called a "stage". A single Curtis stage may consist of two or more rows of moving blades.<br />
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<b>11.What is a diaphragm?</b><br />
Partitions between pressure stages in a turbine’s casing are called diaphragms. They hold the vane-shaped nozzles and seals between the stages. Usually labyrinth-type seals are used. One-half of the diaphragm is fitted into the top of the casing, the other half into the bottom.<br />
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<b>12.What are the two basic types of steam turbines?</b><br />
1.Impulse type.<br />
2.Reaction type.<br />
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<b>13.What are topping and superposed turbines?</b><br />
Topping and superposed turbines arc high-pressure, non-condensing units that can be added to an older, moderate-pressure plant. Topping turbines receive high-pressure steam from new high-pressure boilers. The exhaust steam of the new turbine has the same pressure as the old boilers and is used to supply the old turbines.<br />
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<b>14.What is a combination thrust and radial bearing?</b><br />
This unit has the ends of the Babbitt bearing extended radically over the end of the shell. Collars on the rotor face these thrust pads, and the journal is supported in the bearing between the thrust collars.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-36818177823703394632019-04-17T01:56:00.001-07:002019-04-17T02:07:07.176-07:00Basic Thermal engineering VIVA questions and answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<b><span style="color: blue;">Hired Thermal engineering VIVA questions and answers:</span></b></h3>
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<br />
<b>1. Define heat transfer?</b><br />
Heat transfer can be defined as the transmission of energy from one region to another due to temperature difference.<br />
<br />
<b>2. What are the modes of heat transfer?</b><br />
1. Conduction<br />
2. Convection<br />
3. Radiation.<br />
<br />
<b>3. What is conduction?</b><br />
Heat conduction is a mechanism of heat transfer from a region of high temperature to a region of low temperature within a medium [solid, liquid or gases] or different medium in direct physical contact.<br />
<br />
<b>4. State Fourier’s law of conduction.</b><br />
The rate of heat conduction is proportional to the area measured normal to the direction of heat flow and to the temperature gradient in that direction.<br />
Q α – A dT / dx<br />
Q = -kA dT /dx<br />
Where, A – Area in m2<br />
.<br />
dT / dx – Temperature gradient, K/m<br />
k – Thermal conductivity, W/mK.<br />
<br />
<b>5. Define Thermal conductivity.</b><br />
Thermal conductivity is defined as the ability of a substance to conduct heat.<br />
<br />
<b>6. Write down the equation for conduction of heat through a slab or plane wall.</b><br />
Heat transfer, Q = ∆ Toverall / R<br />
Where, ∆ T = T1 – T2<br />
R = L / kA – Thermal resistance of slab<br />
L – Thickness of slab<br />
K – Thermal conductivity of slab<br />
A – Area<br />
<br />
<b>7. What are the factors affecting the thermal conductivity?</b><br />
a. Moisture b. Density of material c. Pressure<br />
d. Temperature e. Structure of material.<br />
<br />
<b>8. What is meant by free or natural convection?</b><br />
It is fluid motion is produced due to change in density resulting from temperature gradients, the mode of heat transfer is said to be free or natural convection.<br />
<br />
<b>9. Define Grashof number [Gr].</b><br />
It is defined as the ratio of product of inertia force and buoyancy force to the<br />
square of viscous force. Gr = Inertia force x Buoyancy force / [Viscous force]2<br />
<br />
<b>10. Define Stanton number [St].</b><br />
It is the ratio of Nusselt number to the product of Reynolds number and<br />
Prandtl number. St = Nu / Re x Pr.<br />
<br />
<b>11. What is meant by Newtonion and non-newtonion fluids?</b><br />
The fluids which obey the Newton’s law of viscosity are called Newtonion fluids and those which do not obey are called no-newtonion fluids.<br />
<br />
<b>12. What is meant by laminar flow ?</b><br />
Laminar flow: Laminar flow is sometimes called stream line flow. In this type of flow, the fluid moves in layers and each fluid particle follows a smooth continuous path. The fluid particles in each layer remain in an orderly sequence without mixing with each other.<br />
<b><br /></b>
<b>13. Define Convection.</b><br />
Convection is a process of heat transfer that will occur between a solid surface and a fluid medium when they are at different temperatures.<br />
<br />
<b>14. Define Reynolds number [Re].</b><br />
It is defined as the ratio of inertia force to viscous force.<br />
Re = Inertia force / Viscous force<br />
<br />
<b>15. Define Prandtl number [Pr].</b><br />
It is the ratio of the momentum diffusivity to the thermal diffusivity.<br />
Pr = Momentum diffusivity / Thermal diffusivity<br />
<br />
<b>16. Define Nusselt Number [Nu].</b><br />
It is defined as the ratio of the heat flow by convection process under an unit temperature gradient to the heat flow rate by conduction under an unit temperature gradient through a stationary thickness [L] of metre.<br />
<br />
Nusselt Number [Nu] = qconv /qcond<br />
<br />
<b>17. State Newton’s law of convection.</b><br />
Heat transfer from the moving fluid to solid surface is given by the equation.<br />
Q = h A = [Tw - T∞]<br />
This equation is referred to as Newton’s law of cooling.<br />
Where h = Local heat transfer coefficient in W/m2K.<br />
A = Surface area in m2<br />
.<br />
Tw = Surface [or] Wall temperature in K.<br />
T∞ = Temperature of fluid in K.<br />
<br />
<b>18. What is forced convection?</b><br />
If the fluid motion is artificially created by means of an external force like a blower or fan, that type of heat transfer is known as forced convection.<br />
<br />
<b>19. What are the dimensionless parameters used in forced convection?</b><br />
1. Reynolds number [Re].<br />
2. Nusselt number [Nu].<br />
3. Prandtl number [Pr].<br />
<br />
<b>20. Mention Stefan boltzman contant.</b><br />
σ = Stefan Boltzman constant = 5.6697 x 10-8 W/ (m² K4)<br />
<b><br /></b>
<b>21. Define Stefan boltzman contant.</b><br />
Stefan Boltzman law states that the total emissive power of a perfect black body is proportional to<br />
fourth power of the absolute temperature of black body surface<br />
Eb = σT<br />
4<br />
σ = Stefan Boltzman constant = 5.6697 x 10-8 W/ (m² K4)<br />
<br />
<b>22. Define Emissive power [Eb].</b><br />
The emissive power is defined as the total amount of radiation emitted by a body per unit time and unit area. It is expressed in W/m2<br />
<br />
<b>23. Define monochromatic emissive power. [Ebλ]</b><br />
The energy emitted by the surface at a given length per unit time per unit area in all directions is known as monochromatic emissive power.<br />
<br />
<b>24. What is meant by absorptivity?</b><br />
Absorptivity is defined as the ratio between radiation absorbed and incident radiation. Absorptivity, α = Radiation absorbed / Incident radiation.<br />
<br />
<b>25. Define Radiation.</b><br />
The heat transfer from one body to another without any transmitting medium is known as radiation. It is an electromagnetic wave phenomenon.<br />
<br />
<b>26. Define Emissivity.</b><br />
It is defined as the ability of the surface of a body to radiate heat. It is also defined as the ratio of emissive power of any body to the emissive power of a black body of equal temperature.<br />
<br />
Emissivity, ε = E / Eb.<br />
<br />
<b>27. Define Emissive power [Eb].</b><br />
The emissive power is defined as the total amount of radiation emitted by a body per unit time and unit area. It is expressed in W/m2.<br />
<br />
<b>28. Define monochromatic emissive power. [Ebλ]</b><br />
The energy emitted by the surface at a given length per unit time per unit area in all directions is known as monochromatic emissive power.<br />
<br />
<b>29. What is meant by absorptivity?</b><br />
Absorptivity is defined as the ratio between radiation absorbed and incident radiation.<br />
Absorptivity, α = Radiation absorbed / Incident radiation.<br />
<br />
<b>30. What is meant by reflectivity?</b><br />
Reflectivity is defined as the ratio of radiation reflected to the incident radiation.<br />
Reflectivity, ρ = Radiation reflected / Incident radiation.<br />
<br />
<b>31. What is meant by transmissivity?</b><br />
Transmissivity is defined as the ratio of radiation transmitted to the incident radiation.<br />
Transmissivity, τ = Radiation transmitted / Incident radiation.<br />
<br />
<b>32. What is black body?</b><br />
Black body is an ideal surface having the following properties.<br />
1. A black body absorbs all incident radiation, regardless of wav e length and direction.<br />
2. For a prescribed temperature and wave length, no surface can emit more energy than black body.<br />
<br />
<b>33. What is meant by gray body?</b><br />
If a body absorbs a definite percentage of incident radiation irrespective of their wave length, the body is known as gray body. The emissive power of a gray body is always less than that of the black body.<br />
<br />
<b>34. What is heat exchanger?</b><br />
A heat exchanger is defined as an equipment which transfers the heat from a hot fluid to a cold fluid.<br />
<br />
<b>35. What is meant by Direct heat exchanger [or] open heat exchanger?</b><br />
In direct contact heat exchanger, the heat exchange takes place by direct mixing of hot and cold fluids.<br />
<br />
<b>36. What is meant by Indirect contact heat exchanger?</b><br />
In this type of heat exchangers, the transfer of heat between two fluids could be carried out by transmission through a wall which separates the two fluids.<br />
<br />
<b>37. What is meant by parallel flow heat exchanger?</b><br />
In this type of heat exchanger, hot and cold fluids move in the same direction.<br />
<br />
<b>38. What is meant by counter flow heat exchanger?</b><br />
In this type of heat exchanger, hot and cold fluids move in parallel but opposite directions.<br />
<br />
<b>39. What is meant by cross flow heat exchanger?</b><br />
In this type of heat exchanger, hot and cold fluids move at right angles to each other.<br />
<br />
<b>40. What is meant by Shell and tube heat exchanger?</b><br />
In this type of heat exchanger, one of the fluids moves through a bundle of tubes enclosed by a shell. The other fluid is forced through the shell and it movesover the outside surface of the tubes.<br />
<br />
<b>41. What is meant by LMTD?</b><br />
We know that the temperature difference between the hot and cold fluids in the heat exchanger varies from point to point. In addition various modes of heat transfer are involved. Therefore based on concept of appropriate mean temperature difference, also called logarithmic mean temperature difference, the total heat transfer rate in the heat exchanger is expressed as<br />
<br />
Q = U A [∆T]m Where, U=Overall heat transfer co-efficient [W/m2K], A=Area, m2<br />
[∆T]m = Logarithmic mean temperature difference.<br />
<br />
<b>42. What is meant by Effectiveness?</b><br />
The heat exchanger effectiveness is defined as the ratio of actual heat transferto the maximum possible heat transfer.<br />
Effectiveness ε = Actual heat transfer / Maximum possible heat transfer = Q / Qmax<br />
<br />
<b>43. Power requirement of a refrigerator is___________.</b><br />
Inversely proportional to COP.<br />
<br />
<b>44. In SI units, one ton of refrigeration is equal to _________.</b><br />
210 kJ/min.<br />
<br />
<b>45. Define tons of refrigeration and COP.</b><br />
A tonne of refrigeration is defined as the quantity of heat required to beremoved from one tonne of water [1000 kg] at 00C to convert that into ice at 00C in24 hours. In actual practice,1 tonne of refrigeration = 210kJ/min = 3.5kW.<br />
<br />
<b>46. The capacity of a domestic refrigerator is in the range of ___________.</b><br />
1 to 3 tonne.<br />
<br />
<b>47. Name four important properties of a good refrigerant.</b><br />
1. Low boiling point.<br />
2. High critical temperature & pressure.<br />
3. Low specific heat of liquid.<br />
<br />
<b>48. What is the difference between air conditioning and refrigeration?</b><br />
Refrigeration is the process of providing and maintaining the temperature in space below atmospheric temperature. Air conditioning is the process of supplying sufficient volume of clean aircontaining a specific amount of water vapour and maintaining the predeterminedatmospheric condition with in a selected enclosure.<br />
<br />
<b>49. Name any four commonly used refrigerants.</b><br />
1. Ammonia [NH3].<br />
2. Carbon dioxide [CO2].<br />
3. Sulphur di oxide [SO2].<br />
4. Freon – 12. Dr. N.N.C.E MECH/ VI Sem TE LAB II - LM52<br />
<br />
<b>50. What are the advantages and disadvantages of air refrigeration system?</b><br />
Advantages:<br />
1. The refrigerant used namely air is cheap and easily available.<br />
2. There is no danger of fire or toxic effects due to leakages.<br />
3. The weight to tonne of refrigeration ratio is less as compared to other systems.<br />
Disadvantages:<br />
1. The quantity of refrigerant used per tonne of refrigeration is high as compared to other system.<br />
2. The COP of the system is very low. Therefore running cost is high.<br />
3. The danger of frosting at the expander valves is more as the air contains moisture content.<br />
<br />
<b>51. What is net refrigerating effect of the refrigerant?</b><br />
Refrigerating effect is the total heat removed from the refrigerant in the evaporator.<br />
COP = Refrigeration effect / Work done.<br />
Refrigeration effect = COP x Work done.<br />
<br />
<b>52. Define refrigerant.</b><br />
Any substance capable of absorbing heat from another required substance canbe used as refrigerant. </div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-38487559187622011832019-04-15T22:07:00.000-07:002019-04-15T22:07:00.953-07:0050 Most Common Mobile Application (Android) VIVA Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<b>Basic Mobile Application (Android) VIVA Questions and Answers:</b></h3>
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<br />
<b>1) What is Android?</b><br />
It is an open-sourced operating system that is used primarily on mobile devices, such as cell phones and tablets. It is a Linux kernel-based system that’s been equipped with rich components that allows developers to create and run apps that can perform both basic and advanced functions.<br />
<br />
<b>2) What Is the Google Android SDK?</b><br />
The Google Android SDK is a toolset that developers need in order to write apps on Android enabled devices. It contains a graphical interface that emulates an Android driven handheld environment, allowing them to test and debug their codes.<br />
<br />
<b>3) What is the Android Architecture?</b><br />
Android Architecture is made up of 4 key components:<br />
- Linux Kernel<br />
- Libraries<br />
- Android Framework<br />
- Android Applications<br />
<br />
<b>4) Describe the Android Framework.</b><br />
The Android Framework is an important aspect of the Android Architecture. Here you can find all the classes and methods that developers would need in order to write applications on the Android environment.<br />
<br />
<b>5) What is AAPT?</b><br />
AAPT is short for Android Asset Packaging Tool. This tool provides developers with the ability to deal with zip-compatible archives, which includes creating, extracting as well as viewing its contents.<br />
<br />
<b><br /></b><b>6) What is the importance of having an emulator within the Android environment?</b><br />
The emulator lets developers “play” around an interface that acts as if it were an actual mobile device. They can write and test codes, and even debug. Emulators are a safe place for testing codes especially if it is in the early design phase.<br />
<br />
<b>7) What is the use of an activityCreator?</b><br />
An activity Creator is the first step towards the creation of a new Android project. It is made up of a shell script that will be used to create new file system structure necessary for writing codes within the Android IDE.<br />
<br />
<b>8 ) Describe Activities.</b><br />
Activities are what you refer to as the window to a user interface. Just as you create windows in order to display output or to ask for an input in the form of dialog boxes, activities play the same role, though it may not always be in the form of a user interface.<br />
<br />
<b>9) What are Intents?</b><br />
Intents displays notification messages to the user from within the Android enabled device. It can be used to alert the user of a particular state that occurred. Users can be made to respond to intents.<br />
<br />
<b>10) Differentiate Activities from Services.</b><br />
Activities can be closed, or terminated anytime the user wishes. On the other hand, services are designed to run behind the scenes, and can act independently. Most services run continuously, regardless of whether there are certain or no activities being executed.<br />
<br />
<b>11) What items are important in every Android project?</b><br />
These are the essential items that are present each time an Android project is created:<br />
- Android Manifest.xml<br />
- build.xml<br />
- bin/<br />
- src/<br />
- res/<br />
- assets/<br />
<br />
<b>12) What is the importance of XML-based layouts?</b><br />
The use of XML-based layouts provides a consistent and somewhat standard means of setting GUI definition format. In common practice, layout details are placed in XML files while other items are placed in source files.<br />
<b><br /></b><b>13) What are containers?</b><br />
Containers, as the name itself implies, holds objects and widgets together, depending on which specific items are needed and in what particular arrangement that is wanted. Containers may hold labels, fields, buttons, or even child containers, as examples.<br />
<br />
<b>14) What is Orientation?</b><br />
Orientation, which can be set using set Orientation(), dictates if the Linear Layout is represented as a row or as a column. Values are set as either HORIZONTAL or VERTICAL.<br />
<br />
<b>15) What is the importance of Android in the mobile market?</b><br />
Developers can write and register apps that will specifically run under the Android environment. This means that every mobile device that is Android enabled will be able to support and run these apps. With the growing popularity of Android mobile devices, developers can take advantage of this trend by creating and uploading their apps on the Android Market for distribution to anyone who wants to download it.<br />
<br />
<b>16) What do you think are some disadvantages of Android?</b><br />
Given that Android is an open-source platform, and the fact that different Android operating systems have been released on different mobile devices, there’s no clear cut policy to how applications can adapt with various OS versions and upgrades.<br />
--> One app that runs on this particular version of Android OS may or may not run on another version.<br />
--> Another disadvantage is that since mobile devices such as phones and tabs come in different sizes and forms, it poses a challenge for developers to create apps that can adjust correctly to the right screen size and other varying features and specs.<br />
<br />
<b>17) What is adb?</b><br />
Adb is short for "Android Debug Bridge". It allows developers the power to execute remote shell commands. Its basic function is to allow and control communication towards and from the emulator port.<br />
<br />
<b>18) What are the four essential states of an activity?</b><br />
- Active – if the activity is at the foreground<br />
- Paused – if the activity is at the background and still visible<br />
- Stopped – if the activity is not visible and therefore is hidden or obscured by another activity<br />
- Destroyed – when the activity process is killed or completed terminated<br />
<br />
<b>19) What is ANR?</b><br />
ANR is short for Application Not Responding. This is actually a dialog that appears to the user whenever an application have been unresponsive for a long period of time.<br />
<br />
<b>20) Which elements can occur only once and must be present?</b><br />
Among the different elements, the and elements must be present and can occur only once. The rest are optional, and can occur as many times as needed.<br />
<br />
Also Read: 48 TOP BEST Data Structures VIVA Questions and Answers<br />
<br />
<b>21) How are escape characters used as attribute?</b><br />
Escape characters are preceded by double backslashes. For example, a newline character is created using ‘\\n’<br />
<br />
<b>22) What is the importance of settings permissions in app development?</b><br />
Permissions allow certain restrictions to be imposed primarily to protect data and code. Without these, codes could be compromised, resulting to defects in functionality.<br />
<br />
<b>23) What is the function of an intent filter?</b><br />
Because every component needs to indicate which intents they can respond to, intent filters are used to filter out intents that these components are willing to receive. One or more intent filters are possible, depending on the services and activities that is going to make use of it.<br />
<br />
<b>24) Enumerate the three key loops when monitoring an activity?</b><br />
- Entire lifetime – activity happens between on Create and on Destroy<br />
- Visible lifetime – activity happens between on Start and on Stop<br />
- Foreground lifetime – activity happens between on Resume and on Pause<br />
<br />
<b>25) When is the on Stop() method invoked?</b><br />
A call to on Stop method happens when an activity is no longer visible to the user, either because another activity has taken over or if in front of that activity.<br />
<br />
<b>26) Is there a case wherein other qualifiers in multiple resources take precedence over locale?</b><br />
Yes, there are actually instances wherein some qualifiers can take precedence over locale. There are two known exceptions, which are the MCC (mobile country code) and MNC (mobile network code) qualifiers.<br />
<br />
<b>27) What are the different states wherein a process is based?</b><br />
There are 4 possible states:<br />
- foreground activity<br />
- visible activity<br />
- background activity<br />
- empty process<br />
<br />
<b>28) How can the ANR be prevented?</b><br />
One technique that prevents the Android system from concluding a code that has been responsive for a long period of time is to create a child thread. Within the child thread, most of the actual workings of the codes can be placed, so that the main thread runs with minimal periods of unresponsive times.<br />
<br />
<b>29) What role does Dalvik play in Android development?</b><br />
Dalvik serves as a virtual machine, and it is where every Android application runs. Through Dalvik, a device is able to execute multiple virtual machines efficiently through better memory management.<br />
<br />
<b>30) What is the Android Manifest.xml?</b><br />
This file is essential in every application. It is declared in the root directory and contains information about the application that the Android system must know before the codes can be executed.<br />
<br />
<b>31) What is the proper way of setting up an Android-powered device for app development?</b><br />
The following are steps to be followed prior to actual application development in an Android-powered device:<br />
<br />
-Declare your application as “debuggable” in your Android Manifest.<br />
-Turn on “USB Debugging” on your device.<br />
-Set up your system to detect your device.<br />
<br />
<b>32) Enumerate the steps in creating a bounded service through AIDL</b>.<br />
1. create the .aidl file, which defines the programming interface<br />
2. implement the interface, which involves extending the inner abstract Stub class as well as implanting its methods.<br />
3. expose the interface, which involves implementing the service to the clients.<br />
<br />
<b>33) What is the importance of Default Resources?</b><br />
When default resources, which contain default strings and files, are not present, an error will occur and the app will not run. Resources are placed in specially named subdirectories under the project res/ directory.<br />
<br />
<b>34) When dealing with multiple resources, which one takes precedence?</b><br />
Assuming that all of these multiple resources are able to match the configuration of a device, the ‘locale’ qualifier almost always takes the highest precedence over the others.<br />
<b><br /></b><b>35) When does ANR occur?</b><br />
The ANR dialog is displayed to the user based on two possible conditions. One is when there is no response to an input event within 5 seconds, and the other is when a broadcast receiver is not done executing within 10 seconds.<br />
<br />
<b>36) What is AIDL?</b><br />
AIDL, or Android Interface Definition Language, handles the interface requirements between a client and a service so both can communicate at the same level through interprocess communication or IPC. This process involves breaking down objects into primitives that Android can understand. This part is required simply because a process cannot access the memory of the other process.<br />
<br />
<b>37) What data types are supported by AIDL?</b><br />
AIDL has support for the following data types:<br />
-string<br />
-charSequence<br />
-List<br />
-Map<br />
-all native Java data types like int,long, char and Boolean<br />
<br />
<b>38) What is a Fragment?</b><br />
A fragment is a part or portion of an activity. It is modular in a sense that you can move around or combine with other fragments in a single activity. Fragments are also reusable.<br />
<br />
<b>39) What is a visible activity?</b><br />
A visible activity is one that sits behind a foreground dialog. It is actually visible to the user, but not necessarily being in the foreground itself.<br />
<br />
<b>40) When is the best time to kill a foreground activity?</b><br />
The foreground activity, being the most important among the other states, is only killed or terminated as a last resort, especially if it is already consuming too much memory. When a memory paging state has been reach by a foreground activity, then it is killed so that the user interface can retain its responsiveness to the user.<br />
<br />
<b>41) Is it possible to use or add a fragment without using a user interface?</b><br />
Yes, it is possible to do that, such as when you want to create a background behavior for a particular activity. You can do this by using add(Fragment,string) method to add a fragment from the activity.<br />
<br />
<b>42) How do you remove icons and widgets from the main screen of the Android device?</b><br />
To remove an icon or shortcut, press and hold that icon. You then drag it downwards to the lower part of the screen where a remove button appears.<br />
<b><br /></b><b>43) What are the core components under the Android application architecture?</b><br />
There are 5 key components under the Android application architecture:<br />
- services<br />
- intent<br />
- resource externalization<br />
- notifications<br />
- content providers<br />
<br />
<b>44) What composes a typical Android application project?</b><br />
A project under Android development, upon compilation, becomes an .apk file. This apk file format is actually made up of the AndroidManifest.xml file, application code, resource files, and other related files.<br />
<br />
<b>45) What is a Sticky Intent?</b><br />
A Sticky Intent is a broadcast from sendStickyBroadcast() method such that the intent floats around even after the broadcast, allowing others to collect data from it.<br />
<br />
<b>46) Do all mobile phones support the latest Android operating system?</b><br />
Some Android-powered phone allows you to upgrade to the higher Android operating system version. However, not all upgrades would allow you to get the latest version. It depends largely on the capability and specs of the phone, whether it can support the newer features available under the latest Android version.<br />
<br />
<b>47) What is portable wi-fi hotspot?</b><br />
Portable Wi-Fi Hotspot allows you to share your mobile internet connection to other wireless device. For example, using your Android-powered phone as a Wi-Fi Hotspot, you can use your laptop to connect to the Internet using that access point.<br />
<br />
<b>48) What is an action?</b><br />
In Android development, an action is what the intent sender wants to do or expected to get as a response. Most application functionality is based on the intended action.<br />
<b><br /></b><b>49) What is the difference between a regular bitmap and a nine-patch image?</b><br />
In general, a Nine-patch image allows resizing that can be used as background or other image size requirements for the target device. The Nine-patch refers to the way you can resize the image: 4 corners that are unscaled, 4 edges that are scaled in 1 axis, and the middle one that can be scaled into both axes.<br />
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<b>50) What language is supported by Android for application development?</b><br />
The main language supported is Java programming language. Java is the most popular language for app development, which makes it ideal even for new Android developers to quickly learn to create and deploy applications in the Android environment.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com0tag:blogger.com,1999:blog-3432454840355531036.post-49591496527179136492019-04-15T22:03:00.001-07:002019-04-15T22:03:53.473-07:00Hired Digital Logic Design VIVA Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<b>Common Digital Logic Design VIVA Questions and Answers:</b></h3>
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<b>1) Explain about setup time and hold time, what will happen if there is setup time and hold tine violation, how to overcome this? </b><br />
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Set up time is the amount of time before the clock edge that the input signal needs to be stable to guarantee it is accepted properly on the clock edge.<br />
Hold time is the amount of time after the clock edge that same input signal has to be held before changing it to make sure it is sensed properly at the clock edge.<br />
Whenever there are setup and hold time violations in any flip-flop, it enters a state where its output is unpredictable: this state is known as metastable state (quasi stable state); at the end of metastable state, the flip-flop settles down to either '1' or '0'. This whole process is known as metastability<br />
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<b>2) What is skew, what are problems associated with it and how to minimize it? </b><br />
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In circuit design, clock skew is a phenomenon in synchronous circuits in which the clock signal (sent from the clock circuit) arrives at different components at different times.<br />
This is typically due to two causes. The first is a material flaw, which causes a signal to travel faster or slower than expected. The second is distance: if the signal has to travel the entire length of a circuit, it will likely (depending on the circuit's size) arrive at different parts of the circuit at different times. Clock skew can cause harm in two ways. Suppose that a logic path travels through combinational logic from a source flip-flop to a destination flip-flop. If the destination flip-flop receives the clock tick later than the source flip-flop, and if the logic path delay is short enough, then the data signal might arrive at the destination flip-flop before the clock tick, destroying there the previous data that should have been clocked through. This is called a hold violation because the previous data is not held long enough at the destination flip-flop to be properly clocked through. If the destination flip-flop receives the clock tick earlier than the source flip-flop, then the data signal has that much less time to reach the destination flip-flop before the next clock tick. If it fails to do so, a setup violation occurs, so-called because the new data was not set up and stable before the next clock tick arrived. A hold violation is more serious than a setup violation because it cannot be fixed by increasing the clock period.<br />
Clock skew, if done right, can also benefit a circuit. It can be intentionally introduced to decrease the clock period at which the circuit will operate correctly, and/or to increase the setup or hold safety margins. The optimal set of clock delays is determined by a linear program, in which a setup and a hold constraint appears for each logic path. In this linear program, zero clock skew is merely a feasible point.<br />
Clock skew can be minimized by proper routing of clock signal (clock distribution tree) or putting variable delay buffer so that all clock inputs arrive at the same time<br />
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<b>3) What is slack? </b><br />
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'Slack' is the amount of time you have that is measured from when an event 'actually happens' and when it 'must happen’.. The term 'actually happens' can also be taken as being a predicted time for when the event will 'actually happen'.<br />
When something 'must happen' can also be called a 'deadline' so another definition of slack would be the time from when something 'actually happens' (call this Tact) until the deadline (call this Tdead).<br />
Slack = Tdead - Tact.<br />
Negative slack implies that the 'actually happen' time is later than the 'deadline' time...in other words it's too late and a timing violation....you have a timing problem that needs some attention.<br />
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<b>4) What is glitch? What causes it (explain with waveform)? How to overcome it? </b><br />
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The following figure shows a synchronous alternative to the gated clock using a data path. The flip-flop is clocked at every clock cycle and the data path is controlled by an enable. When the enable is Low, the multiplexer feeds the output of the register back on itself. When the enable is High, new data is fed to the flip-flop and the register changes its state<br />
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<b>5) Given only two xor gates one must function as buffer and another as inverter? </b><br />
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Tie one of xor gates input to 1 it will act as inverter.<br />
Tie one of xor gates input to 0 it will act as buffer.<br />
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<b>6) What is difference between latch and flipflop? </b><br />
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The main difference between latch and FF is that latches are level sensitive while FF are edge sensitive. They both require the use of clock signal and are used in sequential logic. For a latch, the output tracks the input when the clock signal is high, so as long as the clock is logic 1, the output can change if the input also changes. FF on the other hand, will store the input only when there is a rising/falling edge of the clock.<br />
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<b>7) Build a 4:1 mux using only 2:1 mux? </b><br />
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<b>8.Difference between heap and stack? </b><br />
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The Stack is more or less responsible for keeping track of what's executing in our code (or what's been "called"). The Heap is more or less responsible for keeping track of our objects (our data, well... most of it - we'll get to that later.).<br />
Think of the Stack as a series of boxes stacked one on top of the next. We keep track of what's going on in our application by stacking another box on top every time we call a method (called a Frame). We can only use what's in the top box on the stack. When we're done with the top box (the method is done executing) we throw it away and proceed to use the stuff in the previous box on the top of the stack. The Heap is similar except that its purpose is to hold information (not keep track of execution most of the time) so anything in our Heap can be accessed at any time. With the Heap, there are no constraints as to what can be accessed like in the stack. The Heap is like the heap of clean laundry on our bed that we have not taken the time to put away yet - we can grab what we need quickly. The Stack is like the stack of shoe boxes in the closet where we have to take off the top one to get to the one underneath it.<br />
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<b>9) Difference between mealy and moore state machine? </b><br />
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A) Mealy and Moore models are the basic models of state machines. A state machine which uses only Entry Actions, so that its output depends on the state, is called a Moore model. A state machine which uses only Input Actions, so that the output depends on the state and also on inputs, is called a Mealy model. The models selected will influence a design but there are no general indications as to which model is better. Choice of a model depends on the application, execution means (for instance, hardware systems are usually best realized as Moore models) and personal preferences of a designer or programmer<br />
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B) Mealy machine has outputs that depend on the state and input (thus, the FSM has the output written on edges)<br />
Moore machine has outputs that depend on state only (thus, the FSM has the output written in the state itself.<br />
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Adv and Disadv<br />
In Mealy as the output variable is a function both input and state, changes of state of the state variables will be delayed with respect to changes of signal level in the input variables, there are possibilities of glitches appearing in the output variables. Moore overcomes glitches as output dependent on only states and not the input signal level.<br />
All of the concepts can be applied to Moore-model state machines because any Moore state machine can be implemented as a Mealy state machine, although the converse is not true.<br />
Moore machine: the outputs are properties of states themselves... which means that you get the output after the machine reaches a particular state, or to get some output your machine has to be taken to a state which provides you the output.The outputs are held until you go to some other state Mealy machine:<br />
Mealy machines give you outputs instantly, that is immediately upon receiving input, but the output is not held after that clock cycle.<br />
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<b>10) Difference between onehot and binary encoding? </b><br />
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Common classifications used to describe the state encoding of an FSM are Binary (or highly encoded) and One hot.<br />
A binary-encoded FSM design only requires as many flip-flops as are needed to uniquely encode the number of states in the state machine. The actual number of flip-flops required is equal to the ceiling of the log-base-2 of the number of states in the FSM.<br />
A onehot FSM design requires a flip-flop for each state in the design and only one flip-flop (the flip-flop representing the current or "hot" state) is set at a time in a one hot FSM design. For a state machine with 9- 16 states, a binary FSM only requires 4 flip-flops while a onehot FSM requires a flip-flop for each state in the design<br />
FPGA vendors frequently recommend using a onehot state encoding style because flip-flops are plentiful in an FPGA and the combinational logic required to implement a onehot FSM design is typically smaller than most binary encoding styles. Since FPGA performance is typically related to the combinational logic size of the FPGA design, onehot FSMs typically run faster than a binary encoded FSM with larger combinational logic blocks<br />
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<b>11) How to achieve 180 degree exact phase shift?</b><br />
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Never tell using inverter<br />
a) dcm’s an inbuilt resource in most of fpga can be configured to get 180 degree phase shift.<br />
b) Bufgds that is differential signaling buffers which are also inbuilt resource of most of FPGA can be used.<br />
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<b>12) What is significance of ras and cas in SDRAM? </b><br />
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SDRAM receives its address command in two address words.<br />
It uses a multiplex scheme to save input pins. The first address word is latched into the DRAM chip with the row address strobe (RAS).<br />
Following the RAS command is the column address strobe (CAS) for latching the second address word.<br />
Shortly after the RAS and CAS strobes, the stored data is valid for reading.<br />
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<b>13) Tell some of applications of buffer? </b><br />
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a)They are used to introduce small delays<br />
b)They are used to eliminate cross talk caused due to inter electrode capacitance due to close routing.<br />
c)They are used to support high fanout,eg:bufg<br />
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<b>14) Implement an AND gate using mux? </b><br />
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This is the basic question that many interviewers ask. for and gate, give one input as select line,incase if u r giving b as select line, connect one input to logic '0' and other input to a.<br />
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<b>15) What will happen if contents of register are shifter left, right? </b><br />
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It is well known that in left shift all bits will be shifted left and LSB will be appended with 0 and in right shift all bits will be shifted right and MSB will be appended with 0 this is a straightforward answer<br />
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What is expected is in a left shift value gets Multiplied by 2 eg:consider 0000_1110=14 a left shift will make it 0001_110=28, it the same fashion right shift will Divide the value by 2.<br />
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<b>16)Given the following FIFO and rules, how deep does the FIFO need to be to prevent underflow or overflow? </b><br />
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RULES:<br />
1) frequency(clk_A) = frequency(clk_B) / 4<br />
2) period(en_B) = period(clk_A) * 100<br />
3) duty_cycle(en_B) = 25%<br />
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Assume clk_B = 100MHz (10ns)<br />
From (1), clk_A = 25MHz (40ns)<br />
From (2), period(en_B) = 40ns * 400 = 4000ns, but we only output for<br />
1000ns,due to (3), so 3000ns of the enable we are doing no output work. Therefore, FIFO size = 3000ns/40ns = 75 entries. </div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com1tag:blogger.com,1999:blog-3432454840355531036.post-88160550971635738562019-04-08T21:21:00.003-07:002019-04-08T21:44:32.781-07:0020 TOP MOST SATELLITE Communication Viva Questions and Answers<div dir="ltr" style="text-align: left;" trbidi="on">
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<b><span style="color: blue;">Satellite Communication VIVA Questions and Answers:</span></b></h3>
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<b>1 What are the Types of Satellite?</b><br />
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Types of Satellite are as under:<br />
► Anti-Satellite weapons/”Killer Satellites”<br />
► Astronomical satellites<br />
► Bio-satellites<br />
► Communications satellites<br />
► Miniaturized satellites<br />
► Navigational satellites<br />
► Reconnaissance satellites<br />
► Earth observation satellites<br />
► Space stations<br />
► Tether satellites<br />
► Weather satellites<br />
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<b>2 How do I interpret visible satellite pictures?</b><br />
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The pictures sent back to us from Weather Satellites are simply photographs taken from outer space. We get visible images during the daylight when the earth reflects sunlight back to outer space. Visible pictures show the amount of light reflected back to outer space. Thick water rich clouds, such as stratus (common along the North Coast during Summer months), show up as bright white on visible pictures. Snow pack over the Sierra Nevada during the Winter is another good reflector of sunlight. During the night, visible pictures are completely black as there is very little or no visible light to reflect!<br />
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<b>3 How do I interpret infrared satellite pictures?</b><br />
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Clouds and atmospheric gases such as water vapor radiate infrared energy to space. The amount of energy radiated by clouds and gasses relates directly with its temperature. This relationship, know as the Stephan-Boltzmann Law, allows us to “see” clouds at night. The atmosphere generally cools with height. A cloud that radiates low energy is higher in the troposphere than a cloud that radiates higher energy. On a standard linear enhancement curve, bright white represent cold ice-crystal clouds, while clouds colored with light shades of gray are warm water filled clouds in the mid and lower troposphere. There are a number of enhancement curves that color pictures of clouds based on temperature. These curves accentuate temperature ranges that allow us to discern high clouds from mid and low clouds. At the bottom of every infrared image there is a key telling you the temperature range for that color. For example, on the infrared pictures provided on this web site, red represents cloud tops with a temperature of -40C which in a standard atmosphere is about 40,000 ft.<br />
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<b>4 How do I interpret water vapor imagery?</b><br />
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Water vapor in the mid and upper troposphere absorbs infrared energy at discrete wavelengths. Using this information, water vapor can act like a tracer of atmospheric circulation in the mid and upper troposphere. Dark regions on water vapor pictures are generally areas where the air is sinking and drying. Light colored regions are areas of rising motion and moisture. Water vapor images are useful in locating jet streams and short-wave troughs and ridges in the mid and upper troposphere, but are lousy when trying to see clouds near the ground such as stratus.<br />
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<b>5 Where can I find the time on satellite pictures? What time zone is this?</b><br />
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The date and time stamps are located at the top or bottom of every image, along with other information. For example, G-10 IMG 01 3 Jun 00 TIME=00:30UTC RES=4km NWS/WR=SSD, is a typical date-time stamp which appears on satellite images. The date and time, colored blue in the above example, is in Universal Coordinated Time (UTC). UTC is also known as Greenwich Mean Time (GMT) or Zulu Time (Z). Along the West Coast, we are about 8 hours behind the UTC during Pacific Standard Time (PST). During Daylight Saving Time (PDT), from mid April through mid October, we are about7 hours behind the UTC. In the example above, it’s June 3rd 2000, 30 minutes past midnight in Greenwich England. In order to get local time, you subtract7 hours to get June 2nd 2000, 5:30PM PDT. The next calendar day has already started in Greenwich England!<br />
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<b>6 What is Anti-satellite weapon?</b><br />
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Anti-satellite weapons (ASAT) are space weapons designed to incapacitate or destroy satellites for strategic military purposes. Currently, only the United States, the former USSR (now Russia) and the People’s Republic of China are known to have developed these weapons. On September 13, 1985, the United States destroyed US satellite P78-1 using an ASM-135 ASAT anti-satellite missile and malfunctioning US spy satellite USA-193 using a RIM-161 Standard Missile 3 on February 21, 2008. On January 11, 2007, China destroyed an old Chinese orbiting weather satellite.<br />
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<b>7 What is Space observatory?</b><br />
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A space observatory is any instrument in outer space which is used for observation of distant planets, galaxies, and other outer space objects. This category is distinct from other observatories located in space that are pointed toward the earth for the purpose of reconnaissance and other types of information gathering.<br />
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<b>8 What is Bio satellite?</b><br />
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A bio satellite is a satellite designed to carry life in space.<br />
NASA launched three satellites specifically named Bio satellite (1, 2 & 3) between 1966 and 1969.<br />
Biosatellites include:<br />
<br />
► Bion series of satellites<br />
► the Mars Gravity Biosatellite.<br />
► Orbiting Frog Otolith<br />
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<b>9 What is Communications satellite?</b><br />
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A communications satellite (sometimes abbreviated to COMSAT) is an artificial satellite stationed in space for the purpose of telecommunications. Modern communications satellites use a variety of orbits including geostationary orbits, Molniya orbits, other elliptical orbits and low (polar and non-polar) Earth orbits.<br />
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<b>10 What is Miniaturized satellite?</b><br />
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Miniaturized satellites or small satellites are artificial satellites of unusually low weights and small sizes, usually under 500 kg (1100 lb). While all such satellites can be referred to as small satellites, different classifications are used to categorize them based on mass.<br />
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<b>11 What is Global navigation satellite system?</b><br />
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Global Navigation Satellite Systems (GNSS) is the standard generic term for satellite navigation systems (“sat nav”) that provide autonomous geo-spatial positioning with global coverage. GNSS allows small electronic receivers to determine their location (longitude, latitude, and altitude) to within a few metres using time signals transmitted along a line-of-sight by radio from satellites. Receivers calculate the precise time as well as position, which can be used as a reference for scientific experiments.<br />
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<b>12 What is Spy satellite?</b><br />
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A spy satellite officially referred to as a reconnaissance satellite is an Earth observation satellite or communications satellite deployed for military or intelligence applications.<br />
These are essentially space telescopes that are pointed toward the Earth instead of toward the stars. The first generation type took photographs, then ejected canisters of photographic film, which would descend to earth.<br />
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<b>13 What is Earth observation satellite?</b><br />
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Earth observation satellites are satellites specifically designed to observe Earth from orbit, similar to reconnaissance satellites but intended for non-military uses such as environmental monitoring, meteorology, map making etc. Geostationary satellites hover over the same spot, providing continuous monitoring to a portion of the Earth’s surface. Polar orbiting satellites provide global coverage, but only twice per day at any given spot.<br />
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<b>14 What is Space station?</b><br />
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A space station is an artificial structure designed for humans to live and work in outer space for a period of time.<br />
To date, only low earth orbital (LEO) stations have been implemented, otherwise known as orbital stations. A space station is distinguished from other manned spacecraft by its lack of major propulsion or landing facilities—instead, other vehicles are used as transport to and from the station. Current and recent-history space stations are designed for medium-term living in orbit, for periods of weeks, months, or even years. The only space station currently in use is the International Space Station. Previous stations include the Almaz and Salyut series, Skylab and Mir.<br />
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<b>15 What is Tether satellite?</b><br />
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Tether satellite is a satellite connected to another by a thin cable called a tether. The space tether idea had its origin in the late 1800s. The idea became more popular in the 1960s, and subsequently NASA examined the feasibility of the idea and gave direction to the study of tethered systems, especially tethered satellites.<br />
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<b>16 Explain Weather satellite?</b><br />
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Weather Satellite is a type of satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be either polar orbiting, seeing the same swath of the Earth every 12 hours, or geostationary, hovering over the same spot on Earth by orbiting over the equator while moving at the speed of the Earths rotation. These meteorological satellites, however, see more than clouds and cloud systems. City lights, fires, effects of pollution, auroras, sand and dust storms, snow cover, ice mapping, boundaries of ocean currents, energy flows, etc., are other types of environmental information collected using weather satellites.</div>
engineering rajuhttp://www.blogger.com/profile/01621364083188249839noreply@blogger.com1tag:blogger.com,1999:blog-3432454840355531036.post-18490580881393910842019-04-08T21:06:00.003-07:002019-04-08T21:06:39.109-07:00Top 10 VIVA QUESTION FOR ANALOG COMMUNICATION<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: blue;">Analog Communication Lab VIVA Questions and Answers:</span></b><br />
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<b>Analog Communication</b> is a data transmitting technique in which information signal is transmitted in analog nature. This always utilizes continuous signals to transmit data which may obtained from audio, image, video etc. An Analog signal is a variable signal continuous in both time and amplitude. To produce modulated signal inside the transmitter in Analog Communication, analog signal modulates the high carrier frequency. Than this modulated signal is transmitted with the help of antenna. All AM, FM audio transmission and T.V. transmission are the most preferable examples of analog communication. Analog communication is very important topic for the students preparing for GATE Exam(Electronics) Following questions will help to learn the basics concepts of analog communication.<br />
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<b>1. What is Sampling? What is Sampling Theorem?</b><br />
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Sampling is defined as the process in which an analog signals are converted into digital signals. It means that a continuous time signal is converted into a discrete time signal.<br />
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Sampling Theorem is defined as : ’The continuous time signal that can be represented in its samples and recovered back if the sampling frequency (fs) is greater than the maximum frequency of the signal (fm) that is fs >2fm’.<br />
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<b>2. Define PAM and write down its drawbacks?</b><br />
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Pulse Amplitude Modulation is the process by which the amplitude of the regularly spaced pulses varies according to the the amplitude of the modulating signal.<br />
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The drawbacks are:<br />
a. Since the amplitude of the pulses varies therefore the peak power of the modulating s/g is much greater.<br />
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b. The bandwidth required for transmitting is greater since the amplitude varies.<br />
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<b>3. What is Modulation? What happens in over modulation?</b><br />
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Modulation is defined as the process in which some characteristics of the signal called carrier is varied according to the modulating or baseband signal. For example – Amplitude Modulation, Phase Modulation, Frequency Modulation.<br />
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In case of over modulation, the modulation index is greater than one and envelope distortion occurs.<br />
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<b>4. What do you mean by Nyquist rate?</b><br />
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In case of Nyquist rate, the sampling frequency is equal to the maximum frequency of the signal and therefore the successive cycles of the spectrum does not overlap.<br />
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<b>5. What do you mean by FM and classify FM.</b><br />
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Frequency Modulation can be defined as the frequency of the carrier (wc) is varied acc. to the modulating signal about an unmodulated frequency.<br />
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FM are of 2 types:<br />
a. Narrowband FM<br />
b. Wideband FM<br />
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<b>6. What is under sampling?</b><br />
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Ans: Under sampling is also known as aliasing effect in which the the sampling frequency is less than the maximum frequency of the signal and therefore the successive cycles of the spectrum overlap.<br />
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<b>7. State the advantages of super heterodyning.</b><br />
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The advantages are:<br />
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a. High selectivity and sensitivity.<br />
b. No change in Bandwidth that is bandwidth remains same all over the operating range.<br />
c. High adjacent channel rejection.<br />
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<b>8. What is multiplexing? Name the types of multiplexing.</b><br />
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Multiplexing is defined as the process in which a number of message signals are combined together to form composite signals so that they can be transmitted through the common channel.<br />
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The two types of multiplexing are:<br />
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a. Frequency Division Multiplexing: In this technique, fixed frequency bands are allotted to every user in the complete channel bandwidth. Such frequency is allotted to user on a continuous basis.<br />
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b. Time Division Multiplexing: When the pulse is present for the short time duration and most of the time their is no signal present in-between them than this free space between the two pulses can occupied by the pulses from other channels. This is known as Time Division Multiplexing.<br />
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<b>9. What is Amplitude Modulation?</b><br />
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Amplitude Modulation is defined as the process in which the instantaneous value of the amplitude of the carrier is varied according to the amplitude of the modulating or base band signal.<br />
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<b>10. How can be aliasing be avoided?</b><br />
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Aliasing can be avoided if:<br />
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a. Sampling frequency must be greater than the frequency of the modulating signal.<br />
b. The frequency should be band limited to maximum frequency of the signal(fm) Htz.<br />
c. If pre-alias filter is used.</div>
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