Electrical Machines If the field of a dc shunt motor gets opened while the motor is running, then the armature current will drop motor will become slow. motor will attain dangerously high speed armature will oscillate about original speed as the mean speed armature current will drop motor will become slow. motor will attain dangerously high speed armature will oscillate about original speed as the mean speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush All of these They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 1, 3 2, 4 1, 4 2, 3 1, 3 2, 4 1, 4 2, 3 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. (3/2)Fmax. Fmax. 3Fmax. (1/2)Fmax. (3/2)Fmax. Fmax. 3Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a fault at the terminal of a synchronous generator, the fault current is maximum for a 3 - phase fault. line to line fault. line to ground fault. 3 - phase to ground fault. 3 - phase fault. line to line fault. line to ground fault. 3 - phase to ground fault. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward-Leonard control is basically a ___________ control method. Armature resistance control. Armature voltage control. Field control. Field diverter control. Armature resistance control. Armature voltage control. Field control. Field diverter control. ANSWER DOWNLOAD EXAMIANS APP