Electrical Machines Ward-Leonard system for controlling the speed of a DC motor is used where Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. All of above. The speed in both the direction is required. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. All of above. The speed in both the direction is required. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : For a level compounded dc generator to run at constant voltage, the series field mmf must effectively compensate 1. armature reaction mmf 2.armature resistance drop 3. brush contact voltage drop Which of these statements is/are correct ? 1 and 3 1 and 2 1, 2 and 3 2 alone 1 and 3 1 and 2 1, 2 and 3 2 alone ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the source voltage of a DC motor is increased, which of the following will decrease? Full load current. Starting torque. Operating speed. Starting torque, operating speed, full load current. Full load current. Starting torque. Operating speed. Starting torque, operating speed, full load current. 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 polarities are properly connected percentage impedances are equal turn- ratios are exactly equal KVA ratings are equal polarities are properly connected percentage impedances are equal turn- ratios are exactly equal ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 400 V, 50 Hz, 30 Hp, three phase IM is drawing 50 A current at 0.8 p.f lagging. The stator and rotor copper losses are 1.5 KW and 900 W respectively. The friction and windage losses are 1050 W and core losses are 1200 W. The air gap power of the motor will be 25 kW. 24.11 kW. 26.21 kW. 23.06 kW. 25 kW. 24.11 kW. 26.21 kW. 23.06 kW. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The type of DC motor generally used for shears and punches is Series motor. Shunt motor. Differential compound motor. Cummulative compound motor. Series motor. Shunt motor. Differential compound motor. Cummulative compound motor. ANSWER DOWNLOAD EXAMIANS APP