electrical engineering MCQs – Page 20

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 Review each marked answer and report any item that may be outdated or unclear.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
381. The maximum load that a power transformer can carry is limited by its________________?
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A. dielectric strength of oil

B. temperature rise

C. voltage ratio

D. copper loss

382. The hum in a transformer is mainly attributed to______________?
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A. magnetostriction

B. mechanical vibrations

C. oil in the transformer

D. load changes

383. The property of a conductor due to which it passes current is called___________?
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A. conductance

B. inductance

C. reluctance

D. resistance

384. An RC snubber network used in BJT__________?
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A. Improves the reverse bias safe operating area

B. All of these

C. Divert the collector current during turn off

D. Dissipates a fair amount of switching power

385. With rise in temperature the resistance of semi-conductors_________________?
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A. increases

B. first increases and then decreases

C. decreases

D. remains constant

386. Varistors are______________?
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A. resistors with zero temperature coefficient

B. insulators

C. non-linear resistors

D. carbon resistors

387. The ac voltage controller can be used for ___________?
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A. Lighting and heating control

B. Soft starting

C. On line transformer tap changing

D. All of these
388. Material used for construction of transformer core is usually___________________?
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A. silicon steel

B. wood

C. aluminium

D. copper

389. The number of electrons in the outer most orbit of carbon atom is___________?
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A. 7

B. 6

C. 4

D. 3

390. In an actual transformer the iron loss remains practically constant from no load to full load because:____________?
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A. permeability of transformer core remains constant

B. value of transformation ratio remains constant

C. secondary voltage remains constant

D. primary voltage remains constant

E. core flux remains practically constant
391. Bulbs in street lighting are all connected in_____________?
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A. series-parallel

B. end-to-end

C. parallel

D. series

392. A combination of synchronized leading edge and trailing edge modulation has also been used to control a____________?
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A. Boost single phase power factor converter

B. A buck dc dc converter to reduce ripple in the intermediate dc bus capacitor

C. Both A. and B.

D. None f these

393. Kingdom Protoctista includes_______________?
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A. Fungi

B. Prokaryotic organisms

C. Unicellular organisms

D. Eu-cariotiquic organisms

394. In a 3 phase VSI SPWM to use a single carrier signal and preserve the features of PWM technique, the normalized carrier frequency should be____________?
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A. Multiple of two

B. Odd multiple of three

C. Odd multiple of seven

D. Odd multiple of five

395. An ideal transformer will have maximum efficiency at a load such that?
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A. none of the above

B. copper loss iron loss

C. copper loss = iron loss
396. In variable frequency, PWM gain
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A. Phase lead helps to decrease the phase margin of the control loop

B. Phase lag helps to decrease the phase margin of the control loop

C. Phase lead helps to increase the phase margin of the control loop

D. Phase lag helps to increase the phase margin of the control loop

397. A 3 Q resistor having 2 A current will dissipate the power of_______________?
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A. 6 watts

B. 2 watts

C. 12 watts

D. 4 watts

398. Which of the following materials has a negative temperature co-efficient of resistance?
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A. Carbon

B. Aluminum

C. Brass

D. Copper

399. The degree of mechanical vibrations produced by the laminations of a transformer depends on____________?
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A. all of the above

B. tightness of clamping

C. size of laminations

D. gauge of laminations

400. In a lossless inverter, the average power absorbed in one period by the load must be__________?
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A. Equal to the average power supplied by the ac source

B. Greater than the average power supplied by the dc source

C. Lesser than the average power supplied by the dc source

D. Equal to the average power supplied by the dc source