Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is 3Fmax. (1/2)Fmax. Fmax. (3/2)Fmax. 3Fmax. (1/2)Fmax. Fmax. (3/2)Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50Hz. The slip of the motor is 4% 25% 5% 2% 4% 25% 5% 2% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called crawling. resonance. cogging. harmonics. crawling. resonance. cogging. harmonics. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3- phase synchronous motor can operate over a wide range of power factors i.e. from lagging to leading power factor. This is achieved by varying the speed. varying the applied voltage. changing the load. changing the field excitation. varying the speed. varying the applied voltage. changing the load. changing the field excitation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the purpose of starting an induction motor, star/delta switch is an equivalent to auto transformer of ratio 50% 57.7% 33.3% 66.3% 50% 57.7% 33.3% 66.3% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Wave winding is prefered for which of the following rating? high current and high voltage high current and low voltage low current and low voltage low current and high voltage high current and high voltage high current and low voltage low current and low voltage low current and high voltage ANSWER DOWNLOAD EXAMIANS APP
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