Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Rf maximum and Ra minimum Ra minimum and Rf minimum Ra maximum and Rf minimum Ra maximum and Rf maximum Rf maximum and Ra minimum Ra minimum and Rf minimum Ra maximum and Rf minimum Ra maximum and Rf maximum ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited DC generator, running at rated speed, has 6 volts across its armature terminals with no field current. When field winding is excited with one ampere, the voltage builds up to 250 V at no load. In case field current is reduced to zero, with the speed remaining unaltered, the armature terminal voltage would be less than 6 V 6 V more than 6 V zero less than 6 V 6 V more than 6 V zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 pole synchronous machine is operating at 3000 rpm. Find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm) ? ωe = 2*ωm ωe = ωm ωe = 1/2*ωm ωe = 4*ωm ωe = 2*ωm ωe = ωm ωe = 1/2*ωm ωe = 4*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The coil spam none of above. may or may not be exactly equal to people pitch. can never be equal to pole pitch. must be exactly equal to people pitch. none of above. may or may not be exactly equal to people pitch. can never be equal to pole pitch. must be exactly equal to people pitch. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hunting in a synchronous motor takes place when load varies. motor is under loaded. when supply voltage fluctuates. when power factor is unity. when load varies. motor is under loaded. when supply voltage fluctuates. when power factor is unity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor when the length of the air gap is increased, the magnetizing current of the motor increases while the short circuit current __________________. remains unchanged. increased. decreased. kept constant to certain value. remains unchanged. increased. decreased. kept constant to certain value. ANSWER DOWNLOAD EXAMIANS APP
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