Electrical Machines Field weakening control method is used for the _________ ? None of these above rated speed below rated speed both A and B None of these above rated speed below rated speed both A and B ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Field weakening method is also called as-----------? constant torque control constant voltage control constant current control constant power control constant torque control constant voltage control constant current control constant power control ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a polyphase induction motor helps to reduce the magnetizing current. reduce the chance of cogging. reduce the chance of crawling. increase the starting torque. reduce the magnetizing current. reduce the chance of cogging. reduce the chance of crawling. increase the starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 volt dc motor has an armature winding resistance of 0.5 ohm. Calculate the emf induced by the motor if the full load armature current is 23 ampere. 220.4 volt. 218.5 volt. 120 volt. None of these. 220.4 volt. 218.5 volt. 120 volt. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The no load current in a transformer lags the applied voltage by about 75°. 90°. about 115°. 0°. about 75°. 90°. about 115°. 0°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 82.5% 72.5% 78.5% 67.5% 82.5% 72.5% 78.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP