Wednesday, 3 September 2014

50 TOP Heating and Welding - Electrical Engineering Multiple choice Questions and Answers

Latest Heating and Welding Questions and Answers List

1.   Which of the following is an advantage of heating by electricity ?
2.   ________ has the highest value of thermal conductivity.
3. Which of the following heating methods has maximum power factor ?
4. method has leading power factor
5. is used for heating non-conducting materials.
6. Which of the following methods of heating is not dependent on the frequency of supply ?
7. When a body reflects entire radiation incident on it, then it is known as
8. For the transmission of heat from one body to another
9. Heat transfer by condition will not occur when
10. A perfect black body is one that
11. Heat is transferred simultaneously by condition, convection and radiation
12. The process of heat transfer during the reentry of satellites and missiles, at very high speeds, into earth's atmosphere is known as
13. Which of the following has the highest value of thermal conductivity ?
14. Induction heating process is based on which of the following principles ?
15. Which of the following insulating materials was suitable for low temperature applications ?
16. A non-dimensional number generally associated with natural convection heat transfer is
17. The temperature inside a furnace is usually measured by which of the following ?
18. Which of the following will happen if the thickness of refractory wall of furnace is increased ?
19. The material of the heating element for a furnace should have
20. In a resistance furnace the atmosphere is
21. By which of the following methods the temperature inside arc nace can be varied ?
22. In induction heating ______ is abnormally high.
23. By the use of which of the following, high frequency power supply for induction furnaces can be obtained ?
24. Induction furnaces are employed for which of the following ?
25. In an electric room heat convector the method of heating used is
26. In a domestic cake baking oven the temperature is controlled by
27. In an electric press mica is used
28. Induction heating takes place in which of the following ?
29. For heating element high resistivity material is chosen to
30. In resistance heating highest working temperature is obtained from heating elements made of
31. For intermittent work which of the following furnaces is suitable ?
32. Due to which of the following reasons it is desirable to have short arc length ?
33. In the indirect resistance heating method, maximum heat-transfer takes place by
34. Properly of low temperature coefficient of heating element is desired due to which of the following reasons ?
35. Which of the following methods is used to control temperature in resistance furnaces ?
36. It is desirable to operate the arc furnaces at power factor of
37. Radiations from a black body are proportional to
38. In arc furnace the function of choke is
39. Ajax Wyatt furnace is started when
40. In electric press, mica is used because it is _______ conductor of heat but/and ________ conductor of electricity.
41. Resistance variation method of temperature control is done by connecting resistance elements in
42. Hysteresis loss and eddy current loss are used in
43. In heating the ferromagnetic material by induction heating, heat is produced due to
44. Radiant heating is used for which of the following ?
45. Which of the following devices is necessarily required for automatic temperature control in a furnace ?
46. For radiant heating around 2250°C, the heating elements are made of
47. Which of the following is an advantage of eddy current heating ?
48. The electrode of a direct arc furnace is made of
49. Direct arc furnaces have which of the following power factors ?
50. In direct arc furnace, which of the following has high value ?

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