electrical engineering MCQs – Page 39

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 Review each marked answer and report any item that may be outdated or unclear.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
761. Which of the following generating machine will offer constant voltage on all loads?
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A. Self-excited generator

B. Separately excited generator

C. Level compounded generator

D. All of the above

762. For a D.C. shunt motor if the excitation is changed_______________?
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A. torque will remain constant

B. torque will change but power will remain constant

C. torque and power both will change

D. torque, power and speed, all will change

763. The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load. The speed regulation of the motor is______________?
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A. 2.36%

B. 6.77%

C. 8.84%

D. 4.76%
764. D.C. generator generally preferred for charging automobile batteries is______________?
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A. shunt generator

B. any ofthe above

C. long shunt compound generator

D. series generator

765. According to Flemings left-hand rule, when the forefinger points in the direction of the field or flux, the middle finger will point in the direction of_________________?
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A. current in the conductor aovtaat of conductor

B. none of the above

C. resultant force on conductor

766. Which of the following tests will be suitable for testing two similar D.C. series motors of large capacity ?
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A. Hopkinsons test

B. Swinburnes test

C. Field test

D. Brake test

767. The losses occurring in a D.C. generator are given below. Which loss is likely to have highest proportion at rated load of the generator ?
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A. field copper loss

B. armature copper loss

C. hysteresis loss

D. eddy current loss

768. The series field of a short-shunt D.C. generator is excited by_______________?
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A. armature current

B. shunt current

C. external current

D. load current
769. Wave winding is composed of_______________?
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A. any odd number of conductors

B. any even number of conductors

C. that even number which is exact multiple of poles + 2

D. that even number which is exact multiple of poles

770. If a D.C. motor is connected across the A.C. supply it will_______________?
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A. run at lower speed

B. burn due to heat produced in the field winding by .eddy currents

C. run at normal speed

D. not run

771. Armature reaction of an unsaturated D.C. machine is_____________?
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A. crossmagnetising

B. none of above

C. demagnetising

D. magnetising

772. The essential condition for parallel operation of two D.C. generators is that they have ________________?
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A. the same operation r.p.m.

B. the same drooping voltage characteristics

C. same percentage regulation

D. same kW rating

773. For both lap and wave windings, there are as many commutator bars as the number of_____________?
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A. armature conductors

B. poles

C. winding elements

D. slots

774. Flashing the field of D.C. generator means:______________?
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A. making the magnetic losses of forces parallel

B. increasing flux density by adding extra turns of windings on poles

C. creating residual magnetism by a D.C. source

D. neutralising residual magnetism

775. Differentially compound D.C. motors can find applications requiring___________?
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A. low starting torque

B. frequent on-off cycles

C. variable speed

D. high starting torque

776. Sparking, is discouraged in a D.C. motor because_____________?
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A. it increases the input power con-sumption

B. commutator gets damaged

C. both A. and B.

D. none of the above

777. Which D.C. motor is preferred for elevators ?
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A. Differential compound motor

B. Shunt motor

C. Cumulative compound motor

D. Series motor

778. D.C. series motors are used______________?
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A. where load changes frequently

B. in none of the above situations

C. where constant operating speed is needed

D. where load is constant

779. In a separately excited generator supplying rated load the armature reaction.
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A. is always present

B. is always absent

C. none of the above

D. may be sometimes present

780. In a D.C. generator, the iron losses mainly take place in___________/
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A. yoke

B. commutator

C. armature rotor

D. armature conductors