Electrical Machines
In DC machines, the interpoles are provided

  to make commutation spark less.
  both (B) and (C).
 to counteract the reactance voltage and the cross-magnetizi
 to counteract demagnetizing effect of armature mmf in commutating zone.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The introduction of interpoles in between the main poles improves the performance of a dc machine, because

 a counter-emf is induced in the coil undergoing commutation
 the interpoles produce additional flux to augment the developed torque
 the flux waveform is improved with reduction in harmonics
 the inequality of air-gap flux on the top and bottom halves of the armature is removed

ANSWER DOWNLOAD EXAMIANS APP