Electrical Machines Which of the following methods of speed control is not affected through stator side? Change of supply voltage. Change of rotor resistance. Change of supply frequency. Change of number of pole. Change of supply voltage. Change of rotor resistance. Change of supply frequency. Change of number of pole. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in dc motor results open circuit. increase in speed. decrease in speed. short circuit. open circuit. increase in speed. decrease in speed. short circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 6 pole DC machine, 90 mechanical degrees correspond to which of the following electrical degree? 30. 270. 45. 180. 30. 270. 45. 180. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The squirrel cage induction motors are provided with blades in order to facilitate cooling of rotor. none of these. eliminate noise. balance the rotor dynamically. facilitate cooling of rotor. none of these. eliminate noise. balance the rotor dynamically. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of 3 - Φ IM, plugging means interchanging two supply phases for quick stopping. pulling the motor directly on line without a rotor. locking of rotor due to harmonics. starting the motor on load which is more than the rated load. interchanging two supply phases for quick stopping. pulling the motor directly on line without a rotor. locking of rotor due to harmonics. starting the motor on load which is more than the rated load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and the flux of a DC motor are held constant and voltage applied across its armature is increased by 5%, the speed of the motor will reduce by 5 %. increase by 5 %. depend on other factors. remain unchanged. reduce by 5 %. increase by 5 %. depend on other factors. remain unchanged. ANSWER DOWNLOAD EXAMIANS APP