Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to None of these reactance voltage induced in the coil. armature emf. coil resistance. None of these reactance voltage induced in the coil. armature emf. coil resistance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A small air gap in poly phase induction motor helps to reduce chance of crawling. increase starting torque. reduce magnetizing current. reduce chance of cogging. reduce chance of crawling. increase starting torque. reduce magnetizing current. reduce chance of cogging. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods of speed control is not affected through stator side? Change of rotor resistance. Change of supply frequency. Change of number of pole. Change of supply voltage. Change of rotor resistance. Change of supply frequency. Change of number of pole. Change of supply voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V dc series generator is driven at its rated speed. The no-load voltage across its armature terminals would be somewhat more than 230 V 230 V somewhat less than 230 V 6 V somewhat more than 230 V 230 V somewhat less than 230 V 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the mechanical angle α between the stator and rotor poles increases, then the stator current Decreases. None of above. Remains unchanged. Increases. Decreases. None of above. Remains unchanged. Increases. ANSWER DOWNLOAD EXAMIANS APP