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. decreased. increased. kept constant to certain value. remains unchanged. decreased. increased. kept constant to certain value. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 82.5% 72.5% 78.5% 67.5% 82.5% 72.5% 78.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If field current is decreased in shunt dc motor, the speed of the motor decreases. None of these remains same. increases. decreases. None of these remains same. increases. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hysteresis loss will depends on f f1.6 f² f³ f f1.6 f² f³ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to None of these reactance voltage induced in the coil. armature emf. coil resistance. None of these reactance voltage induced in the coil. armature emf. coil resistance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor of a 3 - Φ wound induction motor is provided with heavy short-circuited end rings. single phase winding. heavy copper or aluminium bars placed in rotor slots. three phase winding. heavy short-circuited end rings. single phase winding. heavy copper or aluminium bars placed in rotor slots. three phase winding. ANSWER DOWNLOAD EXAMIANS APP
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