Top 250+ Solved Electrical and Electronics Engineering MCQ Questions Answer
Q. The quantity (Ns-N) with respect to I.M. motor is called----
a. slip
b. frequency
c. relative speed
d. speed of rotor
Q. The reactance of the rotor circuit of 3-phase I.M. is maxium at
a. no-load
b. full-load
c. half of full load
d. start
Q. The rotor current in 3-phase I.M. is-----slip
a. inversely proportional to slip
b. directly proportional to slip
c. independent of
d. directly proportional to square of slip
Q. If slip of a 3-phase I.M. increases, the power factor of rotor circuit
a. is decreased
b. is increased
c. remains unchanged
d. none
Q. The slip ring I.M. has high starting ----with ------starting current.
a. low, high
b. low, low
c. high, low
d. high, high
Q. External resistance is added to rotor winding of slip ring I.M to --------starting torque
a. increase
b. decrease
c. to keep constant
d. none of the above
Q. For 6 pole 50Hz I.M, sychronous speed of rotating magnetic field is---------
a. 1200rpm
b. 1000rpm
c. 500rpm
d. 50rpm
Q. For 2 pole 50Hz I.M,sychronous speed of rotating magnetic field is---------rpm
a. 3000
b. 1000
c. 1500
d. 500
Q. for given no. of poles and if supply frequency reduces, sychronous speed of rotating magnetic field
a. remains same
b. decreases
c. increases
d. decreases to half value