Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Star side leads by 30°. Delta side lags by -30°. Delta side leads by 30°. Star side lags by -30°. Star side leads by 30°. Delta side lags by -30°. Delta side leads by 30°. Star side lags by -30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A three phase 400 V, 6 pole, 50 Hz, squirrel cage induction motor is running at a slip of 5%. The speed of stator magnetic field with respect to rotor magnetic field and speed of rotor w.r.t stator magnetic field are 1000 rpm, 950 rpm. zero, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. 1000 rpm, 950 rpm. zero, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type of motors are used for lathes? Cage induction motor. DC shunt motors. Synchronous motor. Either A or B. Cage induction motor. DC shunt motors. Synchronous motor. Either A or B. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Iron losses in a DC machine are independent of variation in speed and voltage. load. speed. voltage. speed and voltage. load. speed. voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Semi closed slots or totally closed slots are used in induction motors, essentially to reduce magnetising current and improve power factor 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 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 72.5% 67.5% 82.5% 78.5% 72.5% 67.5% 82.5% 78.5% ANSWER DOWNLOAD EXAMIANS APP
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