electrical engineering MCQs – Page 47

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 Review each marked answer and report any item that may be outdated or unclear.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
921. If the supply voltage for a D.C. motor is increased, which of the following will decrease ?
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A. Full-load current

B. Operating speed

C. All of the above

D. Starting torque

922. In D.C. generators the polarity of the interpoles_____________?
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A. is the same as that of the immediately preceding pole

B. is opposite to that of the main pole ahead

C. is the same as that of the main pole ahead

D. is neutral as these poles do not play part in generating e.m.f.

923. With the increase in temperature, the speed of DC series motor______________?
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A. increases

B. decreases

C. remain same

D. none of the above

924. Which method of braking is generally used in elevators ?
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A. Plugging

B. None of the above

C. Rheostatic braking

D. Regenerative braking

925. To achieve sparkless commutation brushes of a D.C. generator are rockedm ahead so as to bring them?
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A. in magnetic neutral axis

B. none

C. just behind the magnetic neutral axis

D. just ahead of magnetic neutral axis
926. In which of the following applications D.C. series motor is invariably tried?
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A. Drive for a water pump

B. Starter for a car

C. Fan motor

D. Motor operation in A.C. or D.C

927. Which of the following motor has the poorest speed regulation ?
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A. Differential compound motor

B. Series motor

C. Cumulative compound motor

D. Shunt motor

928. In D.C. generators, current to the external circuit from armature is given through_____________?
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A. solid connection

B. none of above

C. slip rings

D. commutator
929. In case of D.C. machines, mechanical losses are primary function of____________?
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A. current

B. none of above

C. speed

D. voltage

930. D.C. motor is to a drive a load which is almost nil for certain part of the load cycle and peak value for short duration. We will select this______________?
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A. compound motor

B. any of the above

C. shunt motor

D. series motor

931. In lap winding, the number of brushes is always_____________?
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A. two

B. same as the number of poles

C. double the number of poles

D. half the number of poles

932. The power mentioned on the name plate of an electric motor indicates____________?
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A. the gross power

B. the output power available at the shaft

C. the power drawn in kW

D. the power drawn in kVA

933. Which of the following motors one will choose to drive the rotary compressor ?
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A. Synchronous motor

B. D.C. shunt motor

C. Universal motor

D. D.C. series motor

934. Which of the following motors is most suitable for signalling devices and many kinds of timers ?
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A. D.C. series motor

B. D.C. shunt motor

C. Induction motor

D. Reluctance motor
935. Hopkinsons test on D.C. machines is conducted at_______________?
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A. no-load

B. full-load

C. part load

D. overload

936. When the armature of a D.C. motor rotates, e.m.f. induced is___________?
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A. none of the above

B. mutually induced e.m.f.

C. self-induced e.m.f.

D. back e.m.f
937. Which of the following D.C. generators will be in a position to build up without any residual magnetism in the poles?
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A. Series generator

B. Shunt generator

C. None of the above

D. Compound generator

938. Torque developed by a D.C. motor depends upon_____________?
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A. magnetic field

B. current flow through the conductors

C. all above factors

D. radius of armature

E. number of conductors

F. active length of the conductor

939. Which of the following steps is likely to result in reduction of hysteresis loss in a D.C. generator ?
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A. Providing laminations in stator

B. Using non-magnetic material for frame

C. Providing laminations in armature core

D. Using material of low hysteresis co-efficient for armature core material
940. In D.C. motor which of the following can sustain the maximum temperature rise?
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A. Armature winding

B. Commutator

C. Field winding

D. Slip rings