Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 1500 Volt. 0 Volt. 1600 Volt. 2000 Volt. 1500 Volt. 0 Volt. 1600 Volt. 2000 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 65.8 Nm. 74 Nm. 38.5 Nm. 27.73 Nm . 65.8 Nm. 74 Nm. 38.5 Nm. 27.73 Nm . ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous motor, the damper winding is generally used to prevent hunting and provide the starting torque. reduce the eddy currents. provide starting torque only. reduce noise level only. prevent hunting and provide the starting torque. reduce the eddy currents. provide starting torque only. reduce noise level only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor when started on no load does not accelerate up to full speed but runs at 1/7th of the rated speed. The motor is said to be plugging. cogging. crawling. locking. plugging. cogging. crawling. locking. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop DC motor torque. induction motor torque. induction generator torque. synchronous motor torque. DC motor torque. induction motor torque. induction generator torque. synchronous motor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motors has low ratings only? Shaded pole Resistance split phase Capacitor start Capacitor run Shaded pole Resistance split phase Capacitor start Capacitor run ANSWER DOWNLOAD EXAMIANS APP