Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, voltage ratio of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. polarities of all transformers must be same. percentage impedance of all transformers must be same. voltage ratio of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. polarities of all transformers must be same. percentage impedance of all transformers must be same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutator in DC generator is used for increase efficiency collecting of current reduce losses convert AC armature current in to DC increase efficiency collecting of current reduce losses convert AC armature current in to DC ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field winding connection of DC shunt motor is changed It will run in same direction. motor will become slow. motor will not run. It will run in opposite direction. It will run in same direction. motor will become slow. motor will not run. It will run in opposite direction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For successful parallel operation of two single phase transformers, the most essential condition is that their KVA ratings are equal turn- ratios are exactly equal percentage impedances are equal polarities are properly connected KVA ratings are equal turn- ratios are exactly equal percentage impedances are equal polarities are properly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then I1 < I2 None of these I1 = I2 I1 > I2 I1 < I2 None of these I1 = I2 I1 > I2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is increased, the power factor is lagging power factor None of these leading power factor unity power factor lagging power factor None of these leading power factor unity power factor ANSWER DOWNLOAD EXAMIANS APP
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