Power Generator

91. The ac armature winding of an alternator operates at ___________ the field of winding

1. the same voltage as
2. much higher voltage than
3. much lesser voltage than
4. half the voltage than

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92. The air gap in an alternator is ___________ in an induction machine

1. much shorter than
2. about the same as
3. much longer than
4. one-half than

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93. The alternators driven by ___________ do not have a tendency to hunt

1. diesel engines
2. steam engines
3. water turbines
4. prime movers

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94. The amount of back emf of shunt motor will increase when

1. the load is increased
2. the field is strengthen
3. the field is weakened
4. the load is decreased

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95. The amount of copper in the primary is ___________ that of the secondary

1. about the same as
2. smaller than
3. greater than
4. twice

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96. The armature of a dc machine is laminated in order to reduce

1. Eddy current loss
2. Copper loss
3. Hysteresis loss
4. Frictional loss

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97. The armature of a dc machine is made of

1. silicon steel
2. cast steel
3. wrought iron
4. soft iron

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98. The armature winding of a dc Machine is ___________ winding

1. an open circuit
2. a closed circuit
3. partly open circuit and partly closed circuit
4. lap

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99. The armature winding of a dc machine is placed on the rotor to

1. save iron
2. facilitate commutation
3. reduce losses
4. reduce armature reaction

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100. The back emf or counter emf in a dc motor

1. opposes the applied voltage
2. aids the armature current
3. aids the supplied voltage
4. opposes the armature current

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