Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to applied voltage. back emf is equal to half of applied voltage. back emf is equal to twice of applied voltage. none of above. back emf is equal to applied voltage. back emf is equal to half of applied voltage. back emf is equal to twice of applied voltage. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Leading power factor. Lagging power factor. Unity power factor. Zero power factor. Leading power factor. Lagging power factor. Unity power factor. Zero power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Neglecting all losses, the developed torque (T) of DC separately excited motor, operating under constant terminal voltage is reduced to its output power (P) as T is independent of P. T ∝ P. T2 ∝ P3. T ∝ √P. T is independent of P. T ∝ P. T2 ∝ P3. T ∝ √P. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the mechanical angle α between the stator and rotor poles increases, then the stator current Remains unchanged. Decreases. Increases. None of above. Remains unchanged. Decreases. Increases. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Crawling in an induction motor is due to time harmonics in supply. slip ring rotor. space harmonics produced by winding currents. insufficient starting torque. time harmonics in supply. slip ring rotor. space harmonics produced by winding currents. insufficient starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of rotating magnetic field of 8 pole 50 Hz induction motor is 1500 rpm 3000 rpm 1000 rpm 750 rpm 1500 rpm 3000 rpm 1000 rpm 750 rpm ANSWER DOWNLOAD EXAMIANS APP
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