Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to half of applied voltage. none of above. back emf is equal to twice of applied voltage. back emf is equal to applied voltage. back emf is equal to half of applied voltage. none of above. back emf is equal to twice of applied voltage. back emf is equal to applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because field resistance was higher than critical resistance field winding was wrongly connected there was a break in the armature circuit there was no residual magnetism in the field circuit field resistance was higher than critical resistance field winding was wrongly connected there was a break in the armature circuit there was no residual magnetism in the field circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying supply voltage. By varying the supply frequency. Both (A) and (B). By varying number of poles. By varying supply voltage. By varying the supply frequency. Both (A) and (B). By varying number of poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If direct axis reactance Xd and quadrature axis reactance Xq are equal, then reluctance power is minimum All of these maximum zero minimum All of these maximum zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ratio of starting torque to full load torque is minimum in Cumulative compound motor. Series motor. Shunt motor. Differential compound motor. Cumulative compound motor. Series motor. Shunt motor. Differential compound motor. 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 0.02, 0.98 0.02, 1.98 0.04, 1.96 0.04, 0.96 0.02, 0.98 0.02, 1.98 0.04, 1.96 ANSWER DOWNLOAD EXAMIANS APP
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