Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 20% increased by 20% reduced by 10% increased by 10% reduced by 20% increased by 20% reduced by 10% increased by 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following, voltage regulation may be zero or negative leading power factor unity power factor lagging power factor All of these leading power factor unity power factor lagging power factor All of these 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 field resistance was higher than critical resistance there was no residual magnetism in the field circuit field winding was wrongly connected there was a break in the armature circuit field resistance was higher than critical resistance there was no residual magnetism in the field circuit field winding was wrongly connected there was a break in the armature circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the emf generated by the armature is maximum when rate of change of flux is minimum. rate of change of flux is maximum. shaft rotation is high. induced voltage is high. rate of change of flux is minimum. rate of change of flux is maximum. shaft rotation is high. induced voltage is high. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an auto transformer, for what value of turn ratio, power transferred by inductively and conductively are same? 0 1 any of the above 0.5 0 1 any of the above 0.5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If starter is not used with large DC motor for starting, it will damage the armature and commutator. provide execessive voltage drop in line. draw a starting current many times its rated full load current. all of above. damage the armature and commutator. provide execessive voltage drop in line. draw a starting current many times its rated full load current. all of above. ANSWER DOWNLOAD EXAMIANS APP
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