| 1. | An important advantage of a synchronous motor over wound round induction motor is that ? | |
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its power factor may be varied at will
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its speed is independent of supply frequency
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its speed may be controlled more easily
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none of the above
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Report Question| 2. | The speed of a synchronous motor ? | |
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increases as the load increases
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decreases as the load decreases
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always remains constant
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none of the above
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| 3. | The speed regulation of a synchronous motor is always ? | |
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1%
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0.5%
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positive
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zero
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| 4. | The speed of the synchronous motor ? | |
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increases with increase in load
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decreases as load increases
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varies with power factor
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always remains constant
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| 5. | Which of the following 'motors will be used in electric clocks ? | |
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D.C. shunt motor
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D.C. series motor
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A.C. induction motor
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A.C. synchronous motor
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| 6. | In a synchronous motor, damper windings are provided on ? | |
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stator frame
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rotor shaft
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pole faces
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none of the above
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| 7. | In a synchronous motor, the armature current has large values for ? | |
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high excitation only
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low excitation only
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both high and low excitation
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none of the above
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| 8. | Which of the following losses is not dissipated by the stator core surface in a synchronous motor ? | |
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Eddy current losses in the conductors
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Iron losses in the stator
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Copper losses in the slot portion of the conductors
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Windage losses
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| 9. | In a synchronous motor, the break down torque is ? | |
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directly proportional to the applied voltage
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directly proportional to the square of the applied voltage
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inversely proportional to applied voltage
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none of the above
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| 10. | At no-load, the armature current in a synchronous motor ? | |
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is zero
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lags the applied voltage by 90º
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leads the applied voltage by 90º
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is in phase with the applied voltage
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