Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) changes to 0.5 times the original value changes to three times the original value changes to 1.5 times the original value remain the same as the original changes to 0.5 times the original value changes to three times the original value changes to 1.5 times the original value remain the same as the original ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 10% increased by 20% reduced by 20% increased by 10% reduced by 10% increased by 20% reduced by 20% increased by 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines It is advisable to start a DC series motor with some load to Avoid sparking. Limit the speed. Limit the current. Limit the flux. Avoid sparking. Limit the speed. Limit the current. Limit the flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Capacitor start capacitor run provides high staring torque only. high power factor only. high staring torque and high power factor. none. high staring torque only. high power factor only. high staring torque and high power factor. none. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, polarities of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. voltage ratio of all transformers must be same. percentage impedance of all transformers must be same. polarities of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. voltage ratio of all transformers must be same. percentage impedance of all transformers must be same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 4 pole, 50 Hz induction motor 4 % slip, calculate frequency of the rotor emf? 3 Hz. 2 Hz. 10 Hz. 50 Hz. 3 Hz. 2 Hz. 10 Hz. 50 Hz. ANSWER DOWNLOAD EXAMIANS APP
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