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

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

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Armature reaction in a DC machine

  makes an angle of 90° with the main pole axis.
 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.

ANSWER DOWNLOAD EXAMIANS APP