Electrical Machines To increase starting torque of a 3-phase slip ring induction motor, preferred method is to increase supply frequency rotor resistance None of these supply voltage supply frequency rotor resistance None of these supply voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary? It will be doubled. It will becomes four times. It will remain the same. It will be halved. It will be doubled. It will becomes four times. It will remain the same. It will be halved. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in dc motor results decrease in speed. short circuit. increase in speed. open circuit. decrease in speed. short circuit. increase in speed. open circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of these types of motor is used in elevators? None of these. DC series motor. DC shunt motor. DC compound motor. None of these. DC series motor. DC shunt motor. DC compound motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Air core transformer as compared to iron core transformer, has more copper loss. more magnetic core loss. less magnetic core loss. no magnetic core loss. more copper loss. more magnetic core loss. less magnetic core loss. no magnetic core loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because a counter-emf is induced in the coil undergoing commutation the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed ANSWER DOWNLOAD EXAMIANS APP
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