Electrical Machines
Rotor resistance speed control is used in

 slip ring induction motor.
 dc shunt motor.
 synchronous motor.
 squirrel cage induction motor.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Commutation in a DC machine may be explained as a process

 by virtue of which emf is induced in the armature conductors.
  by which electric current in a coil is reversed.
  in which magnetic field is set up.
 how alternate flux affects the main field flux.

ANSWER DOWNLOAD EXAMIANS APP