Electrical Machines What is the frequency of rotor current of 50 Hz induction motor operating at 4% slip? 1 Hz 50Hz 2.5Hz 2HZ 1 Hz 50Hz 2.5Hz 2HZ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 48.0%. 88.8%. 59.2%. 57.1%. 48.0%. 88.8%. 59.2%. 57.1%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Addition of 0.3 % to 4.5 % silicon to iron None of these increases the hysteresis loss. increases the electrical resistivity of iron. reduces the saturation magnetization. None of these increases the hysteresis loss. increases the electrical resistivity of iron. reduces the saturation magnetization. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is increased, the power factor is None of these leading power factor lagging power factor unity power factor None of these leading power factor lagging power factor unity power factor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by the armature of DC motor is directly proportional to The speed of motor. The torque required. None of above. The voltage across the terminals. The speed of motor. The torque required. None of above. The voltage across the terminals. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For successful parallel operation of two single phase transformers, the most essential condition is that their 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 KVA ratings are equal turn- ratios are exactly equal ANSWER DOWNLOAD EXAMIANS APP