Electrical Machines
With the increase in speed of a DC motor

 both back emf as well as line current fall.
 both back emf as well as line current increase.
 back emf increases but line current falls.
 back emf falls and line current increases.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements,

 1, 2 and 3 are correct
 2, 3 and 4 are correct
 1, 2 and 4 are correct
 1 and 4 are correct

ANSWER DOWNLOAD EXAMIANS APP