Electrical Machines
Cogging and crawling are phenomena associated with

 cage induction machines and they are essentially the same.
 any of the above.
 the former during starting and the latter at a fraction of its rated speed.
 the former at a fraction of its rate speed and the latter during starting.

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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

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

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Electrical Machines
In a 3 - Φ induction motor

  none of them.
  power factor at starting in the same as that while running.
  power factor at starting is low as compared to that while running.
  power factor at starting is high as compared to that while running.

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Electrical Machines
In a synchronous generator with constant steam input supplies power to an infinite bus at a lagging power factor. If the excitation is increased

 power angle decrease and power factor increase
 power angle increase and power factor decrease
 both power angle and power factor increase
 both power angle and power factor decrease

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