electrical engineering MCQs – Page 70

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 Review each marked answer and report any item that may be outdated or unclear.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
1381. Which of the following is the disadvantage due to low power factor?
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A. Increased transmission losses

B. High cost of equipment for a given load

C. All of the above

D. Poor voltage regulation

1382. The double energy transient occur in the____________?
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A. purely inductive circuit

B. R-L circuit

C. R-L-C circuit

D. R-C circuit

1383. A sine wave has a frequency of 50 Hz. Its angular frequency is ________ radian/second.
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A. 25 JT

B. 5 n

C. 50 jt

D. 100 n
1384. While starting a salient pole synchronous motor by induction motor action and connecting field discharge resistance across field, starting and accelerating torque is produced by_____________?
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A. eddy current and hysteresis torque in pole faces

B. induction motor torque in field winding

C. reHetance motor torque due to saliency of the rotor

D. induction motor torque in damper winding

E. all of the above methods
1385. In whichof the following power plants the maintenance cost is usually high?
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A. Nuclear power plant

B. Hydro-electric power plants

C. Diesel engine power plants

D. Thermal power plants
1386. A linear resistor having 0 < R < o is a______________?
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A. current controlled resistor

B. voltage controlled resistor

C. both current controlled and voltage controlled resistor

D. none of the above

1387. In a load curve the highest point represents______________?
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A. none of the above

B. diversified demand

C. average demand

D. peak demand
1388. When the field of a synchronous motor is under-excited, the power factor will be____________?
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A. leading

B. lagging

C. unity

D. zero

1389. During load shedding:
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A. system voltage is reduced

B. system frequency is reduced Efficiency is the secondary consideration in

C. some loads are switched off

D. system power factor is changed

1390. The oscillations in a synchronous motor can be damped out by_______________?
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A. oscillations cannot be damped

B. running the motor on leading power factors

C. providing damper bars in the rotor pole faces

D. maintaining constant excitation

1391. A power transformer is usually rated in____________?
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A. kVAR

B. kVA

C. kW

D. kWh

1392. Which of the following should be used for extinguishing electrical fires?
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A. CO2 fire extinguisher

B. Carbon tetrachloride fire extinguisher

C. Foam type fire extinguisher

D. Water

1393. Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?
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A. Low short circuit ratio

B. Low field current

C. High core losses

D. High field current

1394. Direct conversion of heat into electrical energy is possible through____________?
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A. none of the above

B. fuel cells

C. solar cells

D. MHD generators
1395. Power factor of the following circuit will be unity
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A. inductance

B. capacitance

C. resistance

D. both A. and B.

1396. A network which contains one or more than one source of e.m.f. is known as___________?
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A. passive network

B. linear network

C. active network

D. non-linear network

1397. Kirchhoffs current law is applicable to only
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A. electric circuits

B. junction in a network

C. electronic circuits

D. closed loops in a network

1398. _____________can generate power at unpredictable or uncontrolled times?
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A. Any of the above

B. Solar power plant

C. Tidal power plant

D. Wind power plant

1399. The maximum power developed in a synchronous motor will depend on__________?
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A. the supply voltage only

B. the rotor excitation, supply voltage and maximum value of coupling angle (90)

C. the rotor excitation only

D. the rotor excitation and supply volt-age both

E. none of the above

1400. To determine the polarity of the voltage drop across a resistor, it is necessary to know___________?
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A. direction of current through the resistor

B. value of resistor

C. e.m.fs. in the circuit

D. value of current through the resistor