Electrical Machines The material used for commutator brushes is mostly carbon. copper. cast iron. mica. carbon. copper. cast iron. mica. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes increase in speed demanding more armature current. decrease in speed demanding less armature current. decrease in speed but armature current remains the same. increase in speed but armature currnet remains the same. increase in speed demanding more armature current. decrease in speed demanding less armature current. decrease in speed but armature current remains the same. increase in speed but armature currnet remains the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In large sized DC machines the compensating windings are provided to None of these compensate for the decrease in speed due to increase of load. neutralize voltage induced in coil due to fluctuation of l reduce eddy current losses by providing local short circuits. None of these compensate for the decrease in speed due to increase of load. neutralize voltage induced in coil due to fluctuation of l reduce eddy current losses by providing local short circuits. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchorous generator connected to an infinite bus is over excited. Considering only the reactive power from the point view of the system the machine acts as A resistor. A capacitor. None of these. an inductor. A resistor. A capacitor. None of these. an inductor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole, 3-phase induction motor is running at 4% slip at full load. If the speed of the motor is 720 rpm, the supply frequency is 40 HZ 25 Hz 60 Hz 50 Hz 40 HZ 25 Hz 60 Hz 50 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in a DC machine makes an angle with the main pole axis which is load dependent. is in direct opposition to the main poles. makes an angle of 90° with the main pole axis. is in the same direction as the main poles. makes an angle with the main pole axis which is load dependent. is in direct opposition to the main poles. makes an angle of 90° with the main pole axis. is in the same direction as the main poles. ANSWER DOWNLOAD EXAMIANS APP