Electrical Machines
A 3- phase synchronous motor can operate over a wide range of power factors i.e. from lagging to leading power factor. This is achieved by

 varying the speed.
 varying the applied voltage.
 changing the field excitation.
 changing the load.

ANSWER DOWNLOAD EXAMIANS APP

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

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

ANSWER DOWNLOAD EXAMIANS APP