Electric Drives (3160919) MCQs
MCQs of Scalar control or constant V/f control of induction motor
| 11. |
For controlling the speed of an induction motor, if the supply frequency is reduced by 10% then to maintain the same magnetizing current the supply voltage should be
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Answer:
Option (c) |
| 12. |
If the terminal voltage of an induction motor is decreased then current
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Answer:
Option (a) |
| 13. |
A 4 pole 50 Hz induction motor is running at 1300 rpm. Find the speed of stator magnetic field with respect to the rotor?
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Answer:
Option (b) |
| 14. |
If the applied rated voltage per phase is reduced to one-half, then the starting torque of squirrel cage induction motor becomes
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Answer:
Option (c) |
| 15. |
The best method to increase the starting torque of a 3-phase slip ring induction motor is
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Answer:
Option (a) |
| 16. |
What happens if fifth harmonics is given to induction motor?
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Answer:
Option (b) |
| 17. |
If the frequency of 3-phase supply to the stator of a 3-phase induction motor is increased, then synchronous speed
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Answer:
Option (a) |
| 18. |
A 3 phase induction motor is essentially a
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Answer:
Option (a) |
| 19. |
If there are no copper losses in the rotor, then
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Answer:
Option (d) |
| 20. |
If the supply voltage of a 3-phase induction motor is increased two times, then, torque is
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Answer:
Option (a) |
