Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Zero power factor. Leading power factor. Lagging power factor. Unity power factor. Zero power factor. Leading power factor. Lagging power factor. Unity power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC motor, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve and the speed rises. improve and the speed falls. deteriorate and the speed falls. deteriorate and the speed rises. improve and the speed rises. improve and the speed falls. deteriorate and the speed falls. deteriorate and the speed rises. 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 will both increase. The magnetude of current will increase, but power factor will decrease. The magnitude of circuit as well as the power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnitude will both increase. The magnetude of current will increase, but power factor will decrease. The magnitude of circuit as well as the power factor will decrease. The magnitude of current will decrease but the power factor will increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called cogging. harmonics. crawling. resonance. cogging. harmonics. crawling. resonance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Kh is hysteresis constant, f is supply frequency, Bm maximum flux density in core of transformer, the expression of hysteresis loss in transformer, is given by KhfBm. KhfBm1.6. KhfBm3. Khf2Bm1.6. KhfBm. KhfBm1.6. KhfBm3. Khf2Bm1.6. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The interpoles in dc machines have a tapering shape in order to reduce the saturation in the interpole economise on the material required for interpoles and their windings increase the acceleration of commutation reduce the overall weight reduce the saturation in the interpole economise on the material required for interpoles and their windings increase the acceleration of commutation reduce the overall weight ANSWER DOWNLOAD EXAMIANS APP