Single Phase Induction Motors Mcqs - Set 6

1)   Which of the following motor will have relatively higher power factor ?

a. Capacitor run motor
b. Shaded pole motor
c. Capacitor start motor
d. Split phase motor
Answer  Explanation 

ANSWER: Capacitor run motor

Explanation:
No explanation is available for this question!


2)   In a shaded pole motor, the shading coil usually consist of___________?

a. a single turn of heavy wire which is in parallel with running winding
b. a single turn of heavy copper wire which is short-circuited and carries only induced current
c. a multilayer fine gauge copper wire in parallel with running winding
d. none of the above
Answer  Explanation 

ANSWER: a single turn of heavy copper wire which is short-circuited and carries only induced current

Explanation:
No explanation is available for this question!


3)   The rotor developed by a single-phase motor at starting is___________?

a. more than i.he rated torque
b. rated torque
c. less than the rated torque
d. zero
Answer  Explanation 

ANSWER: zero

Explanation:
No explanation is available for this question!


4)   In a split phase motor____________?

a. the starting winding is connected through a centrifugal switch
b. the running winding is connected through a centrifugal switch
c. both starting and running windings are connected through a centrifugal switch
d. centrifugal switch is used to control supply voltage
Answer  Explanation 

ANSWER: the starting winding is connected through a centrifugal switch

Explanation:
No explanation is available for this question!


5)   If the capacitor of a single-phase motor is short-circuited_________?

a. the motor will not start
b. the motor will run
c. the motor will run in reverse direction
d. the motor will run in the same direction at reduced r.p.m
Answer  Explanation 

ANSWER: the motor will not start

Explanation:
No explanation is available for this question!


6)   In a capacitor start and run motors the function of the running capacitor in series with the auxiliary winding is to_______________?

a. improve power factor
b. increase overload capacity
c. reduce fluctuations in torque
d. to improve torque
Answer  Explanation 

ANSWER: improve power factor

Explanation:
No explanation is available for this question!


7)   n a split phase motor, the running winding should have?

a. high resistance and low inductance
b. low resistance and high inductance
c. high resistance as well as high inductance
d. low resistance as well as low inductiance
Answer  Explanation 

ANSWER: low resistance and high inductance

Explanation:
No explanation is available for this question!


8)   In capacitor start single-phase motors____________?

a. current in the starting winding leads the voltage
b. current in the starting winding lags the voltage
c. current in the starting winding is in phase with voltage in running winding
d. none of the above
Answer  Explanation 

ANSWER: current in the starting winding leads the voltage

Explanation:
No explanation is available for this question!


9)   In a capacitor start motor, the phase displacement between starting and running winding can be nearly__________?

a. 10°
b. 30°
c. 60°
d. 90°
Answer  Explanation 

ANSWER: 90°

Explanation:
No explanation is available for this question!


10)   Which of the following motor will give relatively high starting torque ___________?

a. Capacitor start motor
b. Capacitor run motor
c. Split phase motor
d. Shaded pole motor
Answer  Explanation 

ANSWER: Capacitor start motor

Explanation:
No explanation is available for this question!