Electrical Machines
The compensating winding in a DC machine

 is located in armature slots for compensation of the armature reaction.
 is located on commutating poles for improving commutation.
  is located on pole shoes to avoid the sparking at the brushes.
  is located on pole shoes for avoiding the flashover at the commutator.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
In speed control of DC Series motor, speed lower than the rated speed can be obtained by

 Connecting an additional resistance in stator circuit.
 Any of the above.
 Connecting an additional resistance in the field circuit.
 Connecting an additional resistance in the armature circuit.

ANSWER DOWNLOAD EXAMIANS APP