Electrical Machines What is the necessity of copper brushes in a dc motors? To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC generator without commutator is a DC motor AC generator induction motor DC generator DC motor AC generator induction motor DC generator ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz 1-phase induction motor is running at 1470 rpm. Find the forward and backward slips? 0.04, 0.96 0.04, 1.96 0.02, 1.98 0.02, 0.98 0.04, 0.96 0.04, 1.96 0.02, 1.98 0.02, 0.98 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A small air gap in poly phase induction motor helps to increase starting torque. reduce magnetizing current. reduce chance of cogging. reduce chance of crawling. increase starting torque. reduce magnetizing current. reduce chance of cogging. reduce chance of crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage to a dc machine is 230 V, then the back emf, for maximum power developed, is 200 V 115 V 460 V 230 V 200 V 115 V 460 V 230 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions is a dc motor provided with compensating winding used ? 1. Wide range of speed control above normal 2. Wide range of steady load variation with no speed control 3.Wide range of rapid variation in load Select the correct answer using the codes given below : Codes : 1 and 2 1 and 3 2 and 3 1, 2 and 3 1 and 2 1 and 3 2 and 3 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
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