Electrical Machines
The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that

 both Eb and Td are zero
 Eb is unchanged, but Td is zero
 both Eb and Td are unchanged
 Eb is zero, but Td is unchanged

ANSWER DOWNLOAD EXAMIANS APP