electrical engineering MCQs – Page 58

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 Review each marked answer and report any item that may be outdated or unclear.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
1141. Insertion of resistance in the rotor of an induction motor to develop a given torque?
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A. increases the rotor current

B. decreases the rotor current

C. rotor current becomes zero

D. rotor current rernains same
1142. The complete circle diagram of induetion motor can be drawn with the help of data found from__________?
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A. blocked rotor test

B. stator resistance test

C. noload test

D. all of the above
1143. An induction motor is identical to_________?
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A. asynchronous motor

B. D.C. compound motor

C. synchronous motor

D. D.C. series motor

1144. The good power factor of an induction motor can be achieved if the average flux density in the air gap is___________?
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A. large

B. absent

C. small

D. infinity

1145. Which type of load is offered by cranes and hoists ?
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A. Reversing, heavy start

B. Reversing, light start

C. Gradually varying load

D. Non-reversing, no-load start

1146. In repulsion motor, maximum torque is developed when____________?
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A. brush axis is at 45 electrical to the field axis

B. none of the above

C. brush axis is at 90 electrical to the field axis

D. brush axis coincides with the field axis

1147. A three-phase synchronous motor will have_____________?
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A. no slip-rings

B. three slip-rings

C. two slip-rings

D. one slip-ring

1148. A 3-phase slip ring motor has____________?
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A. wound rotor

B. short-circuited rotor

C. double cage rotor

D. any of the above

1149. Lubricant used for ball bearing is usually___________?
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A. mineral oil

B. molasses

C. graphite

D. grease
1150. In medium sized induction motors, the slip is generally around___________?
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A. 0.40%

B. 14%

C. 0.04%

D. 4%
1151. Which of the following statements regarding a reluctance motor is incorrect ?
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A. Its squirrel cage-rotor is of unsym-metrical magnetic construction in order to vary reluctance path between stator and rotor

B. It is nothing else but a single-phase, salient pole synchronous-induction motor

C. It cannot be reversed, ordinarily

D. It requires no D.C. field excitation for its operation

1152. Which of the following single-phase induction motors is generally used in time phonographs ?
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A. Resistance start

B. Shaded pole

C. Capacitor start capacitor run

D. Universal

1153. Which is of the following data is required to draw the circle diagram for an induction motor ?
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A. Block rotor test only

B. No load test only

C. Block rotor test and no-load test

D. Block rotor test, no-load test and stator resistance test
1154. The rotor copper losses, in a synchronous motor, are met by____________?
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A. motor input

B. armature input

C. d.c. source

D. supply lines

1155. The motor used on small lathes is usually_________?
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A. D.C. shunt motor

B. single-phase capacitor run motor

C. universal motor

D. 3-phase synchronous motor

1156. In a A.C. series motor armature coils are usually connected to commutator____________?
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A. through capacitors

B. solidly

C. through resistance

D. through reactances

1157. The capacitors used in single-phase capacitor motors have no__________?
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A. definite value

B. dielectric medium

C. polarity marking

D. voltage rating

1158. As load on an induction motor goes on increasing______________?
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A. its power factor remains constant

B. its power factor goes on decreasing

C. its power factor goes on increasing even after full load

D. its power factor goes on increasing up to full load and then it falls again
1159. Blocked rotor test on induction motors is used to find out?
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A. leakage reactance

B. all of the above

C. power factor on short circuit

D. short-circuit current under rated voltage

1160. Slip ring motor is preferred over squirrel cage induction motor where___________?
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A. load torque is heavy

B. all of the above

C. high starting torque is required

D. heavy pull out torque is required