Single Phase Induction Motors

1. A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will

1. start and then stop
2. start and run slowly
3. start and run at rated speed
4. not start at all

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2. A centrifugal switch is used to dis- connect ‘starting winding when motor has

1. run for about 1 minute
2. run for about 5 minutes
3. picked up about 50 to 70 per cent of rated speed
4. picked up about 10 to 25 per cent of rated speed

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3. A hysteresis motor works on the principle of

1. hysteresis loss
2. magnetisation of rotor
3. eddy current loss
4. electromagnetic induction

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4. A reluctance motor

1. is self-starting
2. is constant speed motor
3. needs no D.C. excitation
4. all of the above

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5. A repulsion motor is equipped with

1. slip rings
2. commutator
3. both (a) and (b)
4. none of the above

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6. A schrage motor can run on

1. zero slip
2. negative slip
3. positive slip
4. all of the above

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7. A shaded pole motor can be used for

1. toys
2. hair dryers
3. circulators
4. any of the above

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8. A shaded pole motor does not possess

1. centrifugal switch
2. capacitor
3. commutator
4. all of the above

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9. A single-phase induction motor is

1. inherently self-starting with high torque
2. inherently self-starting with low torque
3. inherently non-self-starting with low torque
4. inherently non-self-starting with high torque

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10. A universal motor can run on

1. A.C. only
2. D.C. only
3. either A.C. or D.C.
4. none of the above

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