Electrical Machines In an alternator the voltage generated per phase is proportional to frequency of waveform. flux per pole. number of turns in coil. All of these frequency of waveform. flux per pole. number of turns in coil. All of these 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 will both increase. The magnitude of circuit as well as the power factor will decrease. 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 will both increase. The magnitude of circuit as well as the power factor will decrease. The magnetude of current will increase, but power factor will decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an additional resistance is connected in series with a DC series motor operating at rated speed, the speed of the motor will Increase. Remain unaltered. Reduce. Oscillate around the normal speed. Increase. Remain unaltered. Reduce. Oscillate around the normal speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the increase in the torque expressed as percentage of initial torque, if current drawn by the dc series motor is increased from 10A to 11A? 41% 21% 11% 10% 41% 21% 11% 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Addition of 0.3 % to 4.5 % silicon to iron reduces the saturation magnetization. increases the hysteresis loss. None of these increases the electrical resistivity of iron. reduces the saturation magnetization. increases the hysteresis loss. None of these increases the electrical resistivity of iron. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A slip ring Induction motor runs at 290 rpm at full load, when connected to 50 Hz supply. Determine the number of poles and slip. P = 20, s = 3.33 %. P = 60, s = 0.96 %. P = 50, s = 4.43 %. P = 40, s = 5.79 %. P = 20, s = 3.33 %. P = 60, s = 0.96 %. P = 50, s = 4.43 %. P = 40, s = 5.79 %. ANSWER DOWNLOAD EXAMIANS APP