Electrical Machines
A DC shunt generator builds up 230 V when driven in clockwise direction. In case it is driven in anti clockwise direction, other things remaining unchanged, then the voltage build up is

 230 V
 some what more than 230 V
 some what less than 230 V
 not possible

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes :

 1 and 3
 1, 2, and 3
 2, 3 and 4
 1, 2 and 4

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
What will happen if the the supply terminals are reversed in case of a DC shunt motor?

 The motor will run in reverse direction.
 The motor will run much faster in the same direction.
 The motor will stop.
 The motor will run at its normal speed in the same direction as before.

ANSWER DOWNLOAD EXAMIANS APP