Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to over commutation. under commutation. too rapid reversal of current. any of the above. over commutation. under commutation. too rapid reversal of current. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To increase starting torque of a 3-phase slip ring induction motor, preferred method is to increase None of these rotor resistance supply voltage supply frequency None of these rotor resistance supply voltage supply frequency ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power developed by salient pole synchronous machine is/are excitation power only both 1 and 2 power due to saliency or reluctance only None of these excitation power only both 1 and 2 power due to saliency or reluctance only None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following speed control of DC motor the speed obtained is below than the rated speed? Armature circuit resistance control. Any of above. Field resistance control. Armature voltage control. Armature circuit resistance control. Any of above. Field resistance control. Armature voltage control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 400 V, 50 Hz, 30 Hp, three phase IM is drawing 50 A current at 0.8 p.f lagging. The stator and rotor copper losses are 1.5 KW and 900 W respectively. The friction and windage losses are 1050 W and core losses are 1200 W. The air gap power of the motor will be 26.21 kW. 23.06 kW. 25 kW. 24.11 kW. 26.21 kW. 23.06 kW. 25 kW. 24.11 kW. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor when the length of the air gap is increased, the magnetizing current of the motor increases while the short circuit current __________________. remains unchanged. increased. kept constant to certain value. decreased. remains unchanged. increased. kept constant to certain value. decreased. ANSWER DOWNLOAD EXAMIANS APP
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