Electrical Machines
For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load?

 963.8 r.p.m.
 1130 r.p.m.
 4575.4 r.p.m.
 1037.5 r.p.m.

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Electrical Machines
Flashing the field of DC generator means

 increasing flux density by adding extra turns of winding.
  making the magnetic losses forces parallel.
  neutralising residual magnetism.
  creating residual magnetism by a DC source.

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Electrical Machines
An alternator is feeding an infinite busbar. Its prime mover is suddenly shutdown. The alternator will

 continue to work as alternator but the direction of rotation will reverse.
 continue to work as synchronous motor with same direction of rotation.
 come to stand still.
 start working as induction motor.

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