Electrical Machines In case of a conductively compensated DC series motor, the compensating winding is provided As a separate unit. In parallel with the armature winding. In parallel with the field winding. In series with the armature winding. As a separate unit. In parallel with the armature winding. In parallel with the field winding. In series with the armature winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To avoid formation of grooves in the commutator None of these brush position has no effect on the commutator grooving. the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. None of these brush position has no effect on the commutator grooving. the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. 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%. 78.5% 82.5% 72.5% 67.5% 78.5% 82.5% 72.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because there was no residual magnetism in the field circuit field resistance was higher than critical resistance field winding was wrongly connected there was a break in the armature circuit there was no residual magnetism in the field circuit field resistance was higher than critical resistance field winding was wrongly connected there was a break in the armature circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commonly used starters of cage motor is DOL. None of these both A and B. star delta. DOL. None of these both A and B. star delta. 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 Heavy sparking at the first stud of starting resistance steps. Heavy sparking at brushes. Both of above. None of these. Heavy sparking at the first stud of starting resistance steps. Heavy sparking at brushes. Both of above. None of these. ANSWER DOWNLOAD EXAMIANS APP
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