Top 150+ Solved Single Phase Induction Motor MCQ Questions Answer
Q. To reverse the direction of rotation of acapacitor start motor while it is running weshould
a. disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding
b. disconnect motor from supply and immediately reconnect it to supply with reversed connections of the main winding
c. reverse the direction of connection of the auxiliary winding and after motor comes to rest then connect auxiliary winding to the supply
d. reverse the direction of connections of the auxiliary winding and im-mediately connect it to supply
Q. In case of a reluctance motor, when the load is increased so that it cannot maintainsynchronous speed the motor will
a. become unstable
b. draw excessive armature current and may burn out
c. fall out of synchronism and come to stand still
d. run as induction motor
Q. Which of the following motors has two separate windings on the motor ?
a. Repulsion motor
b. Repulsion induction motor
c. Repulsion start induction run motor
d. None of the above
Q. A shaded pole motor does not possess
a. centrifugal switch
b. capacitor
c. commutator
d. all of the above
Q. In a A.C. series motor armature coils are usually connected to commutator
a. through resistance
b. through reactances
c. through capacitors
d. solidly
Q. Which of the following statements regarding a reluctance motor is incorrect ?
a. It cannot be reversed, ordinarily
b. It requires no D.C. field excitation for its operation
c. It is nothing else but a single-phase, salient pole synchronous-induction motor
d. Its squirrel cage-rotor is of unsym-metrical magnetic construction in order to vary reluctance path bet¬ween stator and rotor
Q. A universal motor is one which
a. can be operated either on D.C. or A.C. supply at approximately the same speed and output
b. can be marketed internationally
c. runs at dangerously high speed on no-load
d. none
Q. A repulsion motor is equipped with
a. slip rings
b. commutator
c. both (a) and (b)
d. none of the above
Q. The capacitors used in single-phase capacitor motors have no
a. voltage rating
b. dielectric medium
c. polarity marking
d. definite value
Q. If a D.C. series motor is operated on A.C. supply, it will
a. spark excessively
b. have poor efficiency
c. have poor power factor
d. all of the above
Q. After the starting winding of a single phase induction motor is disconnected fromsupply, it continues to run only on
a. running winding
b. rotor winding
c. field winding
d. compensating winding
Q. Which of the following statements regarding repulsion-start induction motor isincorrect ?
a. It requires more maintenance of commutator and other mechanical devices
b. It makes quite a bit of noise on starting
c. In fractional horse power motors, it has replaced the capacitor motors
d. It is not easily reversed
Q. A.C. series motor as compared to D.C. series motor has
a. smaller brush width
b. less number of field turns
c. more number of armature turns
d. all of the above
Q. Locked rotor current of a shaded pole motor is
a. equal to full load current
b. less than full load current
c. slightly more than full load current
d. several times the full load current
Q. Speed control of a universal motor is achieved by
a. varying field flux with tapped field windings
b. connecting rheostat in series
c. applying variable voltage by means of silicon controlled rectifier
d. all of the above methods