| 1. | Short-circuit test on an induction motor cannot be used to determine ? | |
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windage losses
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copper losses
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transformation ratio
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power scale of circle diagram
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Report Question| 2. | The shape of the torque/slip curve of Induction motor is ? | |
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parabola
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hyperbola
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rectangular parabola
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straight line
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| 3. | slip ring motor is preferred over squirrel cage induction motor where ? | |
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high starting torque is required
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load torque is heavy
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heavy pull out torque is required
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all of the above
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| 4. | When a double squirrel cage motor is started, the current induced in the rotor ? | |
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flows mostly through the upper winding
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flows mostly through the lower winding
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is directly proportional to the impedance offered by each cage
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is equally divided between the two windings
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| 5. | The frame of an induction motor is made of ? | |
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carbon
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Closed grained cast iron
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aluminium
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stainless steel
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| 6. | An induction motor with large number of slots has ? | |
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low over-load capacity
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high over-load capacity
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either of the above
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none of the above
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| 7. | An induction motor has a rated speed of 720 r.p.m. How many poles has its rotating magnetic field ? | |
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8 poles
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6 poles
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4 poles
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2 poles
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| 8. | If a three phase squirrel-cage induction motor runs slow, which of the following could not be the reason for the same ? | |
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Shorted stator coils
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Low voltage
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Overload
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High frequency
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| 9. | Imbalance in shaft of the induction motor occurs due to ? | |
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overheating of the winding
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Air gap is not uniform
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slip rings
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rugged construction
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| 10. | The reversing of 3-phase AC. motor is achieved by ? | |
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star-delta starter
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D.O.L. starter
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an auto-transformer
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interchanging any two of the supply lines
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