Electrical Machines
A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is

 5.7 Ω
 2.2 Ω
 1.9 Ω
 6 Ω

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will

 improve with rise in terminal voltage.
 improve with fall of terminal voltage.
 deteriorate with rise in terminal voltage.
 deteriorate with fall of terminal voltage.

ANSWER DOWNLOAD EXAMIANS APP