Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. over commutation. too rapid reversal of current. any of the above. under commutation. over commutation. too rapid reversal of current. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In 3 - Φ induction motor some times copper bars are placed deep in the rotor to improve efficiency. reduce copper loss. improve power factor. improve starting torque. improve efficiency. reduce copper loss. improve power factor. improve starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the residual magnetism is of the order of 10 %. 2.5 %. 20 %. 15 %. 10 %. 2.5 %. 20 %. 15 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the back emf in DC motor vanishes suddenly the motor will run at very low speed. start haunting. burn. run at very high speed. run at very low speed. start haunting. burn. run at very high speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The flux involved in the emf equation of a transformer has rms value. maximum value. average value. total value. rms value. maximum value. average value. total value. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines High starting torque and low starting current is the advantage of stepper motor. squirrel cage induction motor. hysteresis motor. slip ring induction motor. stepper motor. squirrel cage induction motor. hysteresis motor. slip ring induction motor. ANSWER DOWNLOAD EXAMIANS APP