Electrical Machines A dc shunt generator, when commissioned after a major repair of the field system, failed to build Up voltage. It was because there was a break in the armature circuit field system lost residual magnetism field resistance was higher than critical resistance field winding was wrongly connected there was a break in the armature circuit field system lost residual magnetism field resistance was higher than critical resistance field winding was wrongly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In alternator, the rotary part is magnetic field poles. none of these. armature. core. magnetic field poles. none of these. armature. core. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In travelling cranes for crane travel, trolley and boom hoist which motor is preferred? DC differential compound motor. Slip ring induction motor. Stepper motor. Synchronous motor. DC differential compound motor. Slip ring induction motor. Stepper motor. Synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of None of these. Heavy sparking at the first stud of starting resistance steps. Both of above. Heavy sparking at brushes. None of these. Heavy sparking at the first stud of starting resistance steps. Both of above. Heavy sparking at brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Normally for the design of transformer the ambient temperature is taken as 27°C. 32°C. 45°C. 35°C. 27°C. 32°C. 45°C. 35°C. ANSWER DOWNLOAD EXAMIANS APP
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