Electrical Machines For a dc machine shunt resistance and armature resistance values are low and low high and low high and high low and high low and low high and low high and high low and high ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a star - delta starting of an IM reduced voltage is applied to the stator. applied voltage per stator phase is 57.7 % of a line volt line voltage is 57.7 % of stator voltage. resistance is inserted in the rotor. reduced voltage is applied to the stator. applied voltage per stator phase is 57.7 % of a line volt line voltage is 57.7 % of stator voltage. resistance is inserted in the rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is (1/2)Fmax. Fmax. 3Fmax. (3/2)Fmax. (1/2)Fmax. Fmax. 3Fmax. (3/2)Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3- phase synchronous motor can operate over a wide range of power factors i.e. from lagging to leading power factor. This is achieved by changing the field excitation. changing the load. varying the speed. varying the applied voltage. changing the field excitation. changing the load. varying the speed. varying the applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 4 Ω. 2 Ω. 8 Ω. 10 Ω. 4 Ω. 2 Ω. 8 Ω. 10 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra maximum and Rf maximum Ra minimum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf minimum Ra maximum and Rf maximum Ra minimum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf minimum ANSWER DOWNLOAD EXAMIANS APP