| 1. | The principle of operation of a 3-phase induction motor is most similar to that of ? | |
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transformer with a shorted secondary
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synchronous motor
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capacitor-start induction run motor
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repulsion-start induction motor
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Report Question| 2. | In a squirrel cage motor the induced e.m.f. is ? | |
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dependent on the shaft loading
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dependent on the number of slots
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slip times the stand still e.m.f. induced in the rotor
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none of the above
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| 3. | Insertion of resistance in the rotor of an induction motor to develop a given torque ? | |
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decreases the rotor current
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increases the rotor current
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rotor current becomes zero
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If rotor current remains same
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| 4. | The power factor of an induction motor under no-load conditions will be closer to ? | |
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0.2 lagging
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0.2 leading
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0.5 leading
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unity
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| 5. | When the equivalent circuit diagram of double squirrel-cage induction motor is constructed the two cages can be considered ? | |
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in series
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in parallel
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in series-parallel
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in parallel with stator
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| 6. | The number of slip rings on a squirrel cage induction motor is usually ? | |
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two
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three
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four
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none
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| 7. | In an induction motor, no-load the slip is generally ? | |
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less than 1%
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1.6%
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2%
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4%
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| 8. | A 3-phase induction motor delta connected is carrying foo heavy load and one of its fuses blows out. Then the motor ? | |
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will continue running burning its one phase
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will continue running burning its two phase
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will stop and carry heavy current causing permanent damage to its winding
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will continue running without any harm to the winding
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| 9. | Which type of bearing is provided in small induction motors to support the rotor shaft ? | |
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Ball bearings
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Cast iron bearings
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Bush bearings
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None of the above
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| 10. | When a stationary 3-phase induction motor is switched on with one phase disconnected ? | |
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it will start but run very slowly
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it will make jerky start with loud growling noise
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remaining intact fuses will be blown out due to heavy rush of current
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it is likely to burn out quickly unless immediately disconnected
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