Electrical Machines
No load primary current in a transformer

 leads the applied voltage somewhat less than 90Ã&
 leads the applied voltage by exactly 90Â&
 lags behind applied voltage somewhat less than 90Ã
 lags behind applied voltage by exactly 90Â&am

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,

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

ANSWER DOWNLOAD EXAMIANS APP