Electrical Machines If the number of rotor slots is equal to number of stator slots, then motor refuses to start. Hence it is known as relative speed. air gap. cogging. crawling. relative speed. air gap. cogging. crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An ideal synchronous motor has no starting torque because rotor is made up of salient poles. relative velocity between the stator and rotor mmf’s is zero. rotor winding is highly reactive. relative velocity between stator and rotor mmf’s is not zero. rotor is made up of salient poles. relative velocity between the stator and rotor mmf’s is zero. rotor winding is highly reactive. relative velocity between stator and rotor mmf’s is not zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of residual magnetism. armature reaction. None of these permanent magnets. residual magnetism. armature reaction. None of these permanent magnets. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following relation is correct? None of these Xd < Xq. Xd = Xq. Xd > Xq. None of these Xd < Xq. Xd = Xq. Xd > Xq. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuit test is performed on a transformer with a certain impressed voltage at rated frequency. If the short circuit test is now performed with the same magnitude of impressed voltage, but at frequency higher than the rated frequency then The magnitude of current will decrease but the power factor will increase. The magnitude of circuit as well as the power factor will decrease. The magnitude will both increase. The magnetude of current will increase, but power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnitude of circuit as well as the power factor will decrease. The magnitude will both increase. The magnetude of current will increase, but power factor will decrease. 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 a break in the armature circuit field resistance was higher than critical resistance field winding was wrongly connected there was no residual magnetism in the field circuit there was a break in the armature circuit field resistance was higher than critical resistance field winding was wrongly connected there was no residual magnetism in the field circuit ANSWER DOWNLOAD EXAMIANS APP
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