Top 150+ Solved Single Phase Induction Motor MCQ Questions Answer
Q. Which of the following motors is used for unity power factor ?
a. Hysteresis motor
b. Schrage motor
c. Universal motor
d. Reluctance motor
Q. The motor used for the compressors is
a. d.c. series motor
b. shaded pole motor
c. capacitor-start capacitor-run motor
d. reluctance motor
Q. Which of the following motors is used in a situation where load increases with speed ?
a. Induction motor
b. Three-phase series motor
c. Schrage motor
d. Hysteresis motor
Q. In repulsion motor, zero torque is developed when
a. brush axis is 45° electrical to field axis
b. brush axis coincides with the field axis
c. brush axis is 90° electrical to field axis
d. both (b) and (c)
Q. Centrifugal switch disconnects the auxiliary winding of the motor at about ____percent of synchronous speed
a. 30 to 40
b. 70 to 80
c. 80 to 90
d. 100
Q. Starting winding of a single phase motor of a refrigerator is disconnected from thecircuit by means of a
a. magnetic relay
b. thermal relay
c. centrifugal switch
d. none of the above
Q. If a single phase induction motor runs slower than normal, the most likely defect is
a. worn bearings
b. short-circuit in the winding
c. open-circuit in the winding
d. none of the above
Q. Which of the following motors is used in tape-recorders ?
a. Hysteresis motor
b. Reluctance motor
c. Capacitor-run motor
d. Universal motor
Q. Which of the following statements regarding two value capacitor motor is incorrect ?
a. It is a reversing motor
b. It is preferred to permanent-split single-value capacitor motor where frequent reversals are required
c. It has low starting as well as rush¬ing currents
d. It has high starting torque
Q. Two-value capacitor motor finds increased application as compressor motor in smallhome air-conditioners because
a. it is comparatively cheaper
b. it has almost non-destructible capacitor
c. it has low starting as well as running currents at relatively high power factor
d. it is quiet in operation
Q. If the centrifugal switch of a two-value capacitor motor using two capacitors fails toopen then
a. motor will not come upto speed
b. motor will not carry the load
c. current drawn by the motor will be excessively high
d. electrolytic capacitor will, in all probability, suffer break down
Q. In a universal motor, the most common cause of brush sparking is
a. open armature winding
b. shorted armature winding
c. shorted field winding"
d. all of the above
Q. If starting winding of a single-phase induction motor is left in the circuit, it will
a. run faster
b. spark at light loads
c. draw excessive current and overheat
d. run slower
Q. Most of the fractional horsepower motors have either
a. hard and annealed bearings
b. ball or roller bearings
c. soft and porous bearings
d. plain or sleeve bearings
Q. Which of the following statements regarding reluctance-start motor is incorrect ?
a. It is similar to reluctance motor
b. It is basically an induction motor and not a synchronous one
c. So far as its basic working principle is concerned, it is similar to shaded pole motor
d. the air-gap between rotor and salient poles is non- uniform