electrical engineering MCQs – Page 41

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 Review each marked answer and report any item that may be outdated or unclear.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
801. Which of the following statement about D.C. generators is false ?
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A. Compensating winding in a D.C. machine helps in commutation

B. In a D. C. generator interpoles winding is connected in series with the armature winding

C. Back pitch and front pitch are both odd and approximately equal to the pole pitch

D. Equilizing bus bars are used with parallel running of D.C. shunt generators
802. Which D.C. motor will be suitable along with flywheel for intermittent light and heavy loads?
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A. Cumulatively compounded motor

B. Differentially compounded motor

C. Shunt motor

D. Series motor

803. In D.C. machines fractional pitch winding is used__________?
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A. to increase the generated e.m.f.

B. to reduce copper losses

C. to reduce the sparking

D. to improve cooling

804. A D.C. series motor is that which______________?
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A. has a poor torque

B. has its field winding consisting of thick wire and less turns

C. has almost constant speed

D. can be started easily without load

805. The demagnetising component of armature reaction in a D.C. generator___________?
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A. increases armature speed

B. reduces generator e.m.f.

C. results in sparking trouble

D. reduces interpoles flux density

806. Which of the following method is used for the speed control of DC shunt motor?
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A. voltage control method

B. all of the above

C. rheostat control method

D. flux control method

807. In a D.C. generator in case the resistance of the field winding is increased, then output voltage will____________?
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A. increase

B. remain unaffected

C. decrease

D. fluctuate heavily

808. The speed of a D.C. series motor is_____________?
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A. proportional to the armature current

B. proportional to the square of the armature current

C. proportional to field current

D. inversely proportional to the armature current
809. In a D.C. machine stray loss is the sum of_____________?
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A. shunt field copper loss and mechanical loss

B. total copper loss and mechanical loss

C. armature copper loss and iron loss

D. iron loss and mechanical loss
810. Welding generator will have____________?
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A. duplex wave winding

B. delta winding

C. lap winding

D. wave winding

811. The speed of a D.C. shunt motor is required to be more than full load speed. This is possible by______________?
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A. increasing the excitation current

B. none of the above methods

C. decreasing the armature current

D. reducing the field current

E. increasing the armature current

812. Which of the following components of a D.C, generator plays vital role for providing direct current of a D.C. generator ?
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A. Equilizer rings

B. Eye bolt

C. Dummy coils

D. Commutator
813. A dc series motor should not be started on no load because it would___________?
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A. not develop starting torque

B. fail to start without load

C. run at dangerously high speed

D. draw more current without producing sufficient torque

814. D.C. generators are connected to the busbars or disconnected from them only under the floating condition________________?
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A. to avoid sudden loading of the primemover

B. to avoid mechanicaljerk to the shaft

C. all above

D. to avoid burning of switch contacts

815. Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine ?
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A. 0.005 mm

B. 5 m

C. 0.5 m

D. 0.05 mm

816. Why are the D.C. motors preferred for traction applications ?
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A. Torque and speed are inversely proportional to armature current

B. Torque is proportional to armature current

C. The speed is inversely proportional to the torque and the torque is proportional to square of armature current

D. Torque is proportional to square root of armature current

817. In a DC motor the inter-pole winding is connected in________________?
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A. parallel with armature winding

B. series speed armature winding

C. parallel big field winding

D. series with field winding

818. If a self excited D.C. generator after being installed, fails to build up on its first trial run, the first thing to do is to______________?
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A. increase the speed of primemover

B. reverse the field connections

C. check armature insulation resistance

D. increase the field resistance

819. In over compounded generator, full load terminal voltage is______________?
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A. equal to no-load terminal voltage

B. more than no load terminal voltage

C. less than no load terminal voltage

D. almost zero

820. The armature of D.C. generator is laminated to_______________?
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A. insulate the core

B. reduce the bulk

C. reduce eddy current loss

D. provide the bulk