Electrical Machines Iron losses in a DC machine are independent of variation in speed and voltage. voltage. speed. load. speed and voltage. voltage. speed. load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 10% 40% 5% 19% 10% 40% 5% 19% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 400 A. 40 A. 440 A. 44 A. 400 A. 40 A. 440 A. 44 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What happens if fifth multiples of harmonics is given to induction motor? It will rotates in reverse direction. Either short circuit or open circuit occurs. It will rotates in normal operation. Fail to start. It will rotates in reverse direction. Either short circuit or open circuit occurs. It will rotates in normal operation. Fail to start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Semi closed slots or totally closed slots are used in induction motors, essentially to increase pull out torque improve starting torque decrease starting torque reduce magnetising current and improve power factor increase pull out torque improve starting torque decrease starting torque reduce magnetising current and improve power factor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.125 p.u 0.75 p.u 0.25 p.u 0.5 p.u 0.125 p.u 0.75 p.u 0.25 p.u 0.5 p.u ANSWER DOWNLOAD EXAMIANS APP