Electrical Machines In synchronous motor, the damper winding is generally used to reduce the eddy currents. provide starting torque only. prevent hunting and provide the starting torque. reduce noise level only. reduce the eddy currents. provide starting torque only. prevent hunting and provide the starting torque. reduce noise level only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm. Find the rotor efficiency? 95% 94% 92% 96% 95% 94% 92% 96% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are 4% and 5% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW? None of these 200 MW and 400MW generator 1 gets over load generator 2 gets over load None of these 200 MW and 400MW generator 1 gets over load generator 2 gets over load ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the rotating losses of machine? Hysteresis losses Friction and windage losses All of the them Eddy current losses Hysteresis losses Friction and windage losses All of the them Eddy current losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuit test is performed on a transformer with a certain impressed voltage at rated frequency. If the short circuit test is now performed with the same magnitude of impressed voltage, but at frequency higher than the rated frequency then The magnitude of circuit as well as the power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnetude of current will increase, but power factor will decrease. The magnitude will both increase. The magnitude of circuit as well as the power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnetude of current will increase, but power factor will decrease. The magnitude will both increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to too rapid reversal of current. any of the above. over commutation. under commutation. too rapid reversal of current. any of the above. over commutation. under commutation. ANSWER DOWNLOAD EXAMIANS APP
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