Electrical Machines
Due to magnetic saturation, the flux per pole in a DC machine without brush shift

 decreases in generators and increases in motor with load.
 increases in both the generators and the motors with load.
  decreases in both generators and the motors with load.
 increases in generators but decreases in motor with load.

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Electrical Machines
If two 8-pole dc machines of identical armature sare wound, one with lap winding and the other with wave winding, then

 wave-wound machine will have more rated voltage and less current
 lap-wound machine will have more rated voltage and more current
 wave-wound machine will have more rated current and more voltage
 lap-wound machine will have more rated voltage and less current

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Electrical Machines
A dc shunt generator, when commissioned after a major repair of the field system, failed to build Up voltage. It was because

 field winding was wrongly connected
 field resistance was higher than critical resistance
 there was a break in the armature circuit
 field system lost residual magnetism

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Electrical Machines
The factors that are responsible for decrease in terminal voltage of a shunt generator are

  reduction in field current, effect of armature reaction, armature.
 armature resistance, inter poles, armature.
 armature resistance, effect of armature reaction.
  armature resistance, effect of armature reaction.

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Electrical Machines
A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current

 Would be equal to If1/2.
  Cannot be predicted due to insufficient data.
 Would be equal to If1.
 Woud be equal to 2If1.

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