Electrical Machines
An 8 pole DC generator has 500 armature conductors and useful flux per pole of 0.065 Wb. What will be the emf generated if it is lap connected and runs at 1000 rpm. What must be the speed at which it is driven to produce the same emf if it is wave wound?

 541.67V, 200 rpm.
 2166.67V, 230 rpm.
 541.67V, 250 rpm.
 2166.67V, 270 rpm.

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

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