| 1. | As the load is increased the speed of dc shunt motor will ? | |
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reduce slightly
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increase slightly
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increase proportionately
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remains unchanged
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Report Question| 2. | D.C. generators are normally designed for maximum efficiency around ? | |
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full-load
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rated r.p.m.
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rated voltage
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all of the above
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| 3. | What is the effect produced by the electric current in an electric motor ? | |
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Heating effect only
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Magnetic effect only
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Heating as well as magnetic effect
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Heating as well as chemical effect
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| 4. | The mechanical power developed by a D.C. motor is equal to ? | |
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power input + losses
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back e.m.f x armature current
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power output x losses
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power output x efficiency
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| 5. | The use of armature divertor in rheostatic method of speed control for a D.C. shunt motor makes the method ? | |
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less expensive
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less wasteful
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suitable for rapidly changing loads
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unsuitable for changing loads
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| 6. | Which of the following methods is most effective in finding out the no load losses in a large D.C. shunt motor ? | |
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Field's test
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Ward-Leonard test
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Block rotor test
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Swinburne's test
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| 7. | Which D.C. motor is preferred for elevators ? | |
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Shunt motor
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Series motor
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Differential compound motor
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Cumulative compound motor
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| 8. | Four point starter in the D.C. motor is used ? | |
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to decrease the field current
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to increase the field current
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not to effect the current passing through 'Hold on' coil even if any change in the field current takes place
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all of the above
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| 9. | D.C. motor is to drive a load which has certain minimum value for most of the time and some peak value for short duration. We will select the ? | |
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series motor
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shunt motor
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compound motor
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any of the above
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| 10. | The speed of a D.C. motor, under constant load conditions, is affected by ? | |
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back e.m.f.
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field flux
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armature current
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none of the above
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