| 1. | Which of the following motors is preferred for tape-recorders ? | |
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Shaded pole motor
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Hysteresis motor
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Two value capacitor motor
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Universal motor
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Report Question| 2. | ln case of a shaded pole motor the direction of rotation of the motor is ? | |
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from main pole to shaded pole
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from shaded pole to main pole
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either of the above depending on voltage
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either of the above depending on power factor
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| 3. | Which of the following single-phase motors has relatively poor starting torque ? | |
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Universal motor
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Repulsion motor
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Capacitor motor
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All single phase motors have zero starting torque
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| 4. | Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. ? | |
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shunt motor
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series motor
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compound motor
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separately excited motor
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| 5. | If a single phase induction motor runs slower than normal, the most likely defect is ? | |
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worn bearings
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short-circuit in the winding
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open-circuit in the winding
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none of the above
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| 6. | In a shaded-pole motor, rotating magnetic field is produced by using ? | |
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salient poles
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shading coils
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copper windings
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a capacitor
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| 7. | In a universal motor, normally the ratio of width of brush to the width of commutator segments is ? | |
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6 : l
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4 : 1
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2 : 1
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1 : 1
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| 8. | A capacitor selected for capacitor-run motor should be rated for ? | |
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r.m.s. voltage
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average voltage
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peak voltage
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none of the above
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| 9. | Which of the following statements regarding repulsion induction motor is incorrect ? | |
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At rated load, it runs at almost synchronous speed
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It employs centrifugally-operated mechanism to short-circuit the commutator
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At start as well as a low speeds, most of the torque is produced by repulsion winding
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At starting, squirrel-cage winding produces no torque
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| 10. | To reverse the direction of rotation of a capacitor-start motor while it is running we should ? | |
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disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding
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disconnect motor from supply and immediately reconnect it to supply with reversed connections of the main winding
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reverse the direction of connection of the auxiliary winding and after motor comes to rest then connect auxiliary winding to the supply
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reverse the direction of connections of the auxiliary winding and immediately connect it to supply
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