Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. The frequency of rotor current is 0 Hz 50 Hz 1 Hz 5 Hz 0 Hz 50 Hz 1 Hz 5 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machines, the interpoles are provided to make commutation spark less. to counteract the reactance voltage and the cross-magnetizi both (B) and (C). to counteract demagnetizing effect of armature mmf in commutating zone. to make commutation spark less. to counteract the reactance voltage and the cross-magnetizi both (B) and (C). to counteract demagnetizing effect of armature mmf in commutating zone. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a polyphase induction motor helps to reduce the magnetizing current. increase the starting torque. reduce the chance of cogging. reduce the chance of crawling. reduce the magnetizing current. increase the starting torque. reduce the chance of cogging. reduce the chance of crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer oil is used as a coolant. an insulator. both A and B. inert medium. a coolant. an insulator. both A and B. inert medium. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 ,V 15 , kW 100 rpm shunt motor with armature resistance of 0.25 , W has a rated line current of 68 A and a rated field current of 2.2 A. The change in field flux required to obtain a speed of 1600 rpm while drawing a line current of 52.8 A and a field current of 1.8 A is 18.18% increase 36.36% decrease 36.36% increase 36.36% increase 18.18% increase 36.36% decrease 36.36% increase 36.36% increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Pi and Pc represent core and full load copper loss respectively, the maximum KVA delivered to load corresponding to maximum efficiency is equal to rated KVA is (Pi/Pc)2 Pc/Pi Pi/Pc √(Pi/Pc) (Pi/Pc)2 Pc/Pi Pi/Pc √(Pi/Pc) ANSWER DOWNLOAD EXAMIANS APP