Electrical Machines
The demagnetising component of armature reaction in a DC generator

  reduces inter poles flux density.
  increases armature speed.
  reduces generator emf.
  results in sparking trouble.

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Electrical Machines
In a 3 - Φ induction motor

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

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Electrical Machines
In speed control of DC Series motor, speed lower than the rated speed can be obtained by

 Connecting an additional resistance in the armature circuit.
 Connecting an additional resistance in the field circuit.
 Connecting an additional resistance in stator circuit.
 Any of the above.

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

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Electrical Machines
Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are 4% and 5% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW?

None of these
 200 MW and 400MW
 generator 2 gets over load
 generator 1 gets over load

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