| 1. | When load on an over-excited or underexcited synchronous motor is increased, rate of change of its armature current as compared with that of power factor is ? | |
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more
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less
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equal
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twice
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Report Question| 2. | Dust and dirt accumulation on motor winding will result in ? | |
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rise in winding temperature
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increased core losses
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shorting of coils
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eddy current flow
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| 3. | Which of the following methods is used to start a synchronous motor ? | |
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Damper winding
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Star-delta starter
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Damper winding in conjunction with star-delta starter
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Resistance starter in the armature circuit
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| 4. | Which of the following resistances can be measured by conducting insulation resistance test on a synchronous motor ? | |
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Phase to phase winding resistance
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Stator winding to earthed frame
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Rotor winding to earthed shaft
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All of the above
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| 5. | The induced e.m.f. in a synchronous motor working on leading power factor will be ? | |
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more than the supply voltage
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less than the supply voltage
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equal to the supply voltage
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none
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| 6. | A synchronous motor can be used as a synchronous capacitor when it is ? | |
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under-loaded
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over-loaded
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under-excited
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Over-excited
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| 7. | A synchronous motor is running on a load with normal excitation. Now if the load on the motor is increased ? | |
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power factor as well as armature current will decrease
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power factor as well as armature current will increase
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power factor will increase but armature current will decrease
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power factor will decrease and armature current will increase
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| 8. | In a synchronous motor, the magnitude of stator back e.m.f. Eb depends on ? | |
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d.c. excitation only
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speed of the motor
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load on the motor
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both the speed and rotor flux
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| 9. | Mostly, synchronous motors are of ? | |
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alternator type machines
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induction type machines
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salient pole type machines
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smooth cylindrical type machines
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