Top 250+ Solved Electrical and Electronics Engineering MCQ Questions Answer
Q. The external resistance added in the rotor circuit at start _____.
a. increase the starting torque
b. acts as starter
c. prevents inrush current
d. all of these
Q. A 3 phase induction motor is running with 4% slip. Its rotor input is 10kW then rotor copper losses are
a. 1kw
b. 4kw
c. 400w
d. 0.04kw
Q. A 3 phase I.M. is running with slip 5%. Its air gap power is 12kW then total mechanical power developed is____.
a. 11.4kw
b. 12kw
c. 11.25kw
d. 16.6kw
Q. A 3 phase I.M. running with slip 5%. Its rotor input is 20kW then its power output is ____ if frictional losses are 1kW.
a. 19.75kw
b. 1.8kw
c. 18kw
d. 21kw
Q. A 3 phase I.M. is running with 5% slip. Its rotor input is 20kW and its synchronous speed is 1500rpm then its shaft torque is ___ if frictional losses are 1kW.
a. 226.89nm
b. 120.62nm
c. 135.48nm
d. 214.7nm
Q. A 3 phase I.M. is running with 5% slip. Its rotor input is 20kW then its rotor efficiency is ____.
a. 0.95
b. 0.65
c. 0.75
d. insufficient data
Q. A 25kW, 3 phase I.M. is running with 6% slip. Its rotor copper losses are ____ if frictional losses are 850W.
a. 1700
b. 1650
c. 1550
d. 1400
Q. A 4 pole, 3 phase I.M. is running with a slip of 4% producing shaft torque of 300Nm then its output power is ____ kW.
a. 46.89
b. 28.54
c. 52.12
d. 45.23
Q. For a 3 phase I.M. running at 1440 rpm the torque lost in friction is 50Nm then its frictional losses are____.
a. 7.54
b. 4.23
c. 6.25
d. 8.45
Q. A 3 phase I.M. is running with speed 1455 rpm on full load then its synchronous speed must be ____ rpm.
a. 1600
b. 1500
c. 2000
d. 1000
Q. An induction motor is
a. self starting with zero torque
b. self starting with high torque
c. self starting with small torque as compared to rated torque
d. assisted starting with zero torque
Q. Various methods for starting a three phase induction motor are given, which method will required six stator terminals
a. dol
b. auto transformer
c. start delta
d. rheostat