Electrical Machines Short circuiting is caused in the armature winding due to failure of insulation between two turns of coil. failure of insulation between two commutator bars. any of above. grounding of two or more turns of the same coil. failure of insulation between two turns of coil. failure of insulation between two commutator bars. any of above. grounding of two or more turns of the same coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an AC servomotor has one of its winding excited by AC, then voltage measured at the other winding with rotor running will be zero. constant independent of speed. proportional to square of rotor speed. proportional to rotor speed. zero. constant independent of speed. proportional to square of rotor speed. proportional to rotor speed. ANSWER DOWNLOAD EXAMIANS APP
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 resistance was higher than critical resistance field system lost residual magnetism field winding was wrongly connected there was a break in the armature circuit field resistance was higher than critical resistance field system lost residual magnetism field winding was wrongly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 2, 5 2, 3, 4 1, 3, 5 1, 2, 3, 4 1, 2, 5 2, 3, 4 1, 3, 5 1, 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Generators work on the principle of production of statically induced emf. None of these dynamically and statically induced emf. dynamically induced emf. statically induced emf. None of these dynamically and statically induced emf. dynamically induced emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Resistance commutation is used generally in case of None of these DC machines above 10 kW. DC machines bellow 5 kW. fractional kW DC machines. None of these DC machines above 10 kW. DC machines bellow 5 kW. fractional kW DC machines. ANSWER DOWNLOAD EXAMIANS APP
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