Electrical Machines
Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to

  reactance voltage induced in the coil.
None of these
  coil resistance.
 armature emf.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Armature reaction in a DC machine

 makes an angle with the main pole axis which is load dependent.
 is in the same direction as the main poles.
 is in direct opposition to the main poles.
  makes an angle of 90° with the main pole axis.

ANSWER DOWNLOAD EXAMIANS APP