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

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

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The coil spam

 must be exactly equal to people pitch.
 none of above.
  may or may not be exactly equal to people pitch.
 can never be equal to pole pitch.

ANSWER DOWNLOAD EXAMIANS APP