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
If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated)

 changes to three times the original value
 remain the same as the original
 changes to 1.5 times the original value
 changes to 0.5 times the original value

ANSWER DOWNLOAD EXAMIANS APP