Electrical Machines
What is/are the necessary conditions for voltage build up in self excited generator?

 Poles should contain residual flux.
 Field winding resistance should be less than critical resistance.
All of these
 Field winding should be properly connected to armature winding.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The armature mmf of a DC machine has

  triangular space distribution and is stationary in space.
  triangular space distribution and rotates at the speed of armature.
  trapezoidal space distribution and is stationary in space.
 stepped distribution and rotates at the speed of armature.

ANSWER DOWNLOAD EXAMIANS APP