Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will open fuse or circuit breaker. draw too much current. produce sparking at brushes. develop excessive speed and damage itself. open fuse or circuit breaker. draw too much current. produce sparking at brushes. develop excessive speed and damage itself. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the back emf in DC motor vanishes suddenly the motor will start haunting. run at very low speed. run at very high speed. burn. start haunting. run at very low speed. run at very high speed. burn. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In large sized DC machines the compensating windings are provided to None of these reduce eddy current losses by providing local short circuits. neutralize voltage induced in coil due to fluctuation of l compensate for the decrease in speed due to increase of load. None of these reduce eddy current losses by providing local short circuits. neutralize voltage induced in coil due to fluctuation of l compensate for the decrease in speed due to increase of load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The torque angle, in a synchronous motor, is the angle between None of these magnetizing electric current and back emf. the supply voltage and the back emf. the rotating stator flux and rotor flux. None of these magnetizing electric current and back emf. the supply voltage and the back emf. the rotating stator flux and rotor flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then E ∝ φ/f E ∝ 1/(φf) E ∝ f/φ E ∝ φf E ∝ φ/f E ∝ 1/(φf) E ∝ f/φ E ∝ φf ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the phase difference between two windings of A.C servomotor ? 120°. 90°. 30°. 60°. 120°. 90°. 30°. 60°. ANSWER DOWNLOAD EXAMIANS APP
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