Electrical Machines No load primary current in a transformer lags behind applied voltage somewhat less than 90à lags behind applied voltage by exactly 90Â&am leads the applied voltage by exactly 90Â& leads the applied voltage somewhat less than 90Ã& lags behind applied voltage somewhat less than 90à lags behind applied voltage by exactly 90Â&am leads the applied voltage by exactly 90Â& leads the applied voltage somewhat less than 90Ã& ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 V DC generator in run at rated speed with no excitation. The open circuit voltage will be zero. about 100 V. very small, say about 2 or 3 V. 250 V. zero. about 100 V. very small, say about 2 or 3 V. 250 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) remain the same as the original changes to 1.5 times the original value changes to 0.5 times the original value changes to three times the original value remain the same as the original changes to 1.5 times the original value changes to 0.5 times the original value changes to three times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The total core loss of a 400 V, 50 Hz transformer is 2400W, when it is supplied by 200 V, 25 Hz loss is 800W. Calculate eddy current loss and hysteresis loss? 1000W , 1400W 800W, 1600W 1400W, 1000W 1600W, 800W 1000W , 1400W 800W, 1600W 1400W, 1000W 1600W, 800W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 5 KVA transformer has a turns ratio of N1/N2 = 10. The impedance of primary winding is 3+j5 ohms while that of secondary winding is 0.5+j0.8 ohms. The impedance of transformer when referred to primary will be 53+j85 ohms 3.05+j5.08 ohms 3.5+j5.8 ohms 8+j13 ohms 53+j85 ohms 3.05+j5.08 ohms 3.5+j5.8 ohms 8+j13 ohms ANSWER DOWNLOAD EXAMIANS APP
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 increased by 20% reduced by 20% increased by 10% reduced by 10% increased by 20% reduced by 20% increased by 10% reduced by 10% ANSWER DOWNLOAD EXAMIANS APP
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