electrical engineering MCQs – Page 252

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 Review each marked answer and report any item that may be outdated or unclear.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 generation2. analog electronics3. solid state switching circuits4. parallel circuits5. switchgear and protection6. op amp circuits7. transistor audio power amplifiers8. electrostatics9. heating and welding10. multi stage transistor amplifiers11. passive filters12. network theorems13. regulated d c power supply14. a c fundamentals circuits and circuit theory15. electromagnetic induction16. power electronics17. magnetism and electromagnetism18. transformers19. modulation and demodulation20. d c generators21. semiconductor theory22. single phase induction motors23. semiconductor diode24. hybrid parameters25. digital electronics26. oscillators27. earthing or grounding28. single stage transistor amplifiers29. d c motors30. transistor biasing31. amplifiers with negative feedback32. basic electrical33. electronic instruments34. synchronous motors35. field effect transistors fet36. magnetic circuit37. control systems38. industrial drives39. power generation40. series parallel circuits41. transistor tuned amplifiers42. electrical engineering materials43. rectifiers and converters44. integrated circuits45. scr silicon controlled rectifiers46. cables47. polyphase induction motors48. measurement and instrumentation49. transistors50. electrical machine design51. electrolysis and storage of batteries52. electric traction53. transmission and distribution
5021. Which of the following is the main advantage of an auto-transformer over a two winding transformer?
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A. Saving in winding material

B. Eddy losses are totally eliminated

C. Copper losses are negligible

D. Hysteresis losses are reduced

5022. Which of the following properties is not necessarily desirable for the material for transformer core ?
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A. High thermal conductivity

B. Low hysteresis loss

C. Adequate mechanical strength

D. High permeability

5023. Which winding in a transformer has more number of turns ?
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A. High voltage winding

B. Low voltage winding

C. Secondary winding

D. Primary winding

5024. If a transformer is continuously operated the maximum temperature rise will occur in_______________?
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A. windings

B. any of the above

C. core

D. tank

5025. For given applied voltage, with the increase in frequency of the applied voltage?
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A. eddy current loss will remain unchanged

B. eddy current loss will decrease

C. eddy current loss will increase

D. none of the above

5026. The transformer oil should have _______ volatility and _______ viscosity?
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A. low,high

B. high,high

C. low,low

D. high,low

5027. In an actual transformer the iron loss remains practically constant from no load to full load because:____________?
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A. secondary voltage remains constant

B. core flux remains practically constant

C. permeability of transformer core remains constant

D. value of transformation ratio remains constant

E. primary voltage remains constant

5028. The degree of mechanical vibrations produced by the laminations of a transformer depends on____________?
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A. gauge of laminations

B. all of the above

C. size of laminations

D. tightness of clamping

5029. Which of the following insulating materials can withstand the highest temperature safely ?
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A. Glass fibre

B. Asbestos

C. Mica

D. Cellulose

5030. The dielectric strength of transformer oil is expected to be______________?
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A. 33 kV

B. lkV

C. 100 kV

D. 330 kV

5031. In a transformer routine efficiency depends upon_____________?
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A. supply frequency

B. load current

C. power factor of load

D. both B. and (c)
5032. While conducting short-circuit test on a transformer the following side is short circuited?
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A. Primary side

B. Low voltage side

C. Secondary side

D. High voltage side

5033. The permissible flux density in case of cold rolled grain oriented steel is around__________?
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A. 1.7 Wb/m2

B. 3.7 Wb/m2

C. 2.7 Wb/m2

D. 4.7 Wb/m2

5034. Two transformers are connected in parallel. These transformers do not have equal percentage impedance. This is likely to result in____________?
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A. loading of the transformers not in proportion to their kVA ratings

B. power factor of one of the transformers is leading while that of the other lagging

C. transformers having higher copper losses will have negligible core losses

D. short-circuiting of the secondaries

5035. Distribution transformers are generally designed for maximum efficiency around________________?
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A. 90% load

B. zero load

C. 50% load

D. 25% load

5036. Transformer breaths in when_______________?
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A. load remains constant

B. load on it decreases

C. load on it increases

D. none of the above

5037. During short circuit test iron losses are negligible because of _____________?
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A. full-load current is not supplied to the transformer

B. the voltage applied on primary side is low

C. the current on secondary side is negligible

D. the voltage on secondary side does not vary

5038. The chemical used in breather for transformer should have the quality of____________?
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A. ionizing air

B. cleansing the transformer oil

C. absorbing moisture

D. cooling the transformer oil

5039. Sumpners test is conducted on transformers to determine_____________?
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A. none of the above

B. temperature

C. stray losses

D. all-day efficiency

5040. The no-load current drawn by transformer is usually what per cent of the full-load current ?
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A. 20 to 30 per cent

B. 0.2 to 0.5 per cent

C. 2 to 5 per cent

D. 12 to 15 per cent