electrical engineering MCQs – Page 253

Practise multiple-choice questions from electrical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

electrical engineering Mcqs

1. economics of power generation 2. analog electronics 3. solid state switching circuits 4. parallel circuits 5. switchgear and protection 6. op amp circuits 7. transistor audio power amplifiers 8. electrostatics 9. heating and welding 10. multi stage transistor amplifiers 11. passive filters 12. network theorems 13. regulated d c power supply 14. a c fundamentals circuits and circuit theory 15. electromagnetic induction 16. power electronics 17. magnetism and electromagnetism 18. transformers 19. modulation and demodulation 20. d c generators 21. semiconductor theory 22. single phase induction motors 23. semiconductor diode 24. hybrid parameters 25. digital electronics 26. oscillators 27. earthing or grounding 28. single stage transistor amplifiers 29. d c motors 30. transistor biasing 31. amplifiers with negative feedback 32. basic electrical 33. electronic instruments 34. synchronous motors 35. field effect transistors fet 36. magnetic circuit 37. control systems 38. industrial drives 39. power generation 40. series parallel circuits 41. transistor tuned amplifiers 42. electrical engineering materials 43. rectifiers and converters 44. integrated circuits 45. scr silicon controlled rectifiers 46. cables 47. polyphase induction motors 48. measurement and instrumentation 49. transistors 50. electrical machine design 51. electrolysis and storage of batteries 52. electric traction 53. transmission and distribution

5041. No-load on a transformer is carried out to determine______________?
0

A. efficiency of the transformer

B. magnetising current and loss

C. magnetising current

D. copper loss

5042. If R2 is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be___________?
0

A. R2IK2

B. R22!K2

C. R22/K

D. R2/VK

5043. The changes in volume of transformer cooling oil due to variation of atmospheric temperature during day and night is taken care of by which part of transformer?
0

A. Bushings

B. Conservator

C. Buchholz relay

D. Breather

5044. When secondary of a current transformer is open-circuited its iron core will be__________?
0

A. none of above will happen

B. hot because of heavy iron losses taking place in it due to high flux density

C. hot because primary will carry heavy current

D. cool as there is no secondary current

5045. Which of the following does not change in an ordinary transformer ?
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A. Voltage

B. Frequency

C. Current

D. Any of the above

5046. Silicon steel used in laminations mainly reduces___________?
0

A. all of the above

B. copper losses

C. hysteresis loss

D. eddy current losses

5047. A Buchholz relay can be installed on______________?
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A. air-cooled transformers

B. oil cooled transformers

C. uchholz relay can be installed on

D. auto-transformers

E. welding transformers

5048. Which of the following is the most likely source of harmonics in a transformer ?
0

A. Overload

B. loose connections

C. poor insulation

D. Core saturation

5049. The leakage flux in a transformer depends upon______________?
0

A. load current, voltage, frequency and power factor

B. load current

C. load current and voltage

D. load current, voltage and frequency

5050. For a transformer, operating at constant load current, maximum efficiency will occur at______________?
0

A. 0.8 lagging power factor

B. 0.8 leading power factor

C. unity power factor

D. zero power factor

5051. Helical coils can be used on___________________?
0

A. low voltage side of high kVA transformers

B. high voltage side of high kVA rating transformers

C. high frequency transformers

D. high voltage side of small capacity transformers

5052. In the transformer following winding has got more cross-sectional area______________?
0

A. High voltage winding

B. Primary winding

C. Secondary winding

D. Low voltage winding

5053. If the percentage impedances of the two transformers working in parallel are different, then______________________?
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A. transformers will be overheated

B. power factors of both the transformers will be same

C. parallel operation will be not possible

D. parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load

5054. A transformer transforms__________________?
0

A. power

B. current

C. voltage

D. frequency

5055. An ideal transformer will have maximum efficiency at a load such that?
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A. copper loss iron loss

B. copper loss = iron loss

C. none of the above

5056. In a transformer the resistance between its primary and secondary is____________?
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A. 1 ohm

B. 1000 ohms