Electrical Machines
To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be

 increased by 20%
 reduced by 20%
 increased by 10%
 reduced by 10%

ANSWER DOWNLOAD EXAMIANS APP

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

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

ANSWER DOWNLOAD EXAMIANS APP