electrical engineering MCQs – Page 53

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 Review each marked answer and report any item that may be outdated or unclear.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
1041. A synchronous motor develops maximum power when load angle is____________?
comments icon0

A. 60

B. 90

C. 45

D. 120

1042. The torque of a rotor in an induction motor under running condition is maximum__________?
comments icon0
A. at the value of the slip which makes rotor reactance per phase equal to the resistance per phase

B. at the value of the slip which makes the rotor reactance half of the rotor

C. at the zero value of slip

D. at the unit value of slip

1043. A universal motor is one which______________?
comments icon0

A. runs at dangerously high speed on no-load

B. can be operated either on D.C. or A.C. supply at approximately the same speed and output

C. can be marketed internationally

1044. Which of the following motors has two separate windings on the motor ?
comments icon0

A. Repulsion start induction run motor

B. Repulsion induction motor

C. Repulsion motor

D. None of the above

1045. The starting torque of a 3-phase squirrel cage induction motor is____________?
comments icon0
A. 1.5 times the full load torque

B. twice the full load torque

C. equal to full load torque

1046. In split-phase motor auxiliary winding is of___________?
comments icon0

A. thick wire placed at the top of the slots

B. thin wire placed at the bottom of the slots

C. thick wire placed at the bottom of the slots

D. thin wire placed at the top of the slots
1047. If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in_________?
comments icon0
A. damage to the starting winding

B. none of the above

C. overloading of running winding

D. damage to the centrifugal switch

1048. In a universal motor, the most common cause of brush sparking is___________?
comments icon0

A. high commutator mica

B. shorted armature winding

C. open armature winding

D. all of the above

E. shorted field winding

1049. Which of the following component is usually fabricated out of silicon steel ?
comments icon0

A. None of the above

B. Shaft

C. Statorcore

D. Bearings

1050. For which of the applications a reluctance motor is preferred ?
comments icon0

A. Refrigerators

B. Electric shavers

C. Signalling and timing devices

D. Lifts and hoists

1051. Which of the following motors is preferred for tape-recorders ?
comments icon0

A. Two value capacitor motor

B. Hysteresis motor

C. Universal motor

D. Shaded pole motor

1052. . In a synchronous motor which loss varies with load ?
comments icon0

A. Bearing friction loss

B. Windage loss

C. Copper loss

D. Core loss

1053. An induction motor is__________?
comments icon0
A. self-starting with low torque

B. non-self starting

C. self-starting with high torque

D. self-starting with zero torque

1054. In induction motor, percentage slip depends on__________?
comments icon0

A. none of the above

B. copper losses in motor

C. supply voltage

D. supply frequency

1055. In a synchronous motor, the magnitude of stator back e.m.f. Eb depends on___________?
comments icon0

A. load on the motor

B. d.c. excitation only

C. both the speed and rotor flux

D. none of the above

1056. The angle between the rotating stator flux and rotor poles is called _________ angle.
comments icon0

A. power factor

B. torque

C. obtuse

D. synchronizing

1057. Most of the fractional horsepower motors have either___________?
comments icon0

A. hard and annealed bearings

B. ball or roller bearings

C. soft and porous bearings

D. plain or sleeve bearings
1058. When V is the applied voltage, then the breakdown torque of a synchronous motor varies as_________?
comments icon0

A. V312

B. V

C. V2

D. 1/V

1059. Insertion of reactance in the rotor circuit_______?
comments icon0

A. increases starting torque but maxi-mum torque remains unchanged

B. increases starting torque but maxi-mum torque decreases

C. reduces starting torque as well as maximum torque

D. increases starting torque as well as maximum torque

1060. In three-phase induction motors sometimes copper bars are placed deep in the rotor to___________?
comments icon0

A. improve efficiency

B. improve power factor

C. reduce copper losses

D. improve starting torque