Commissioning of single phase motors special motors - Electrical Engineering (MCQ) questions and answers

1)   At what angle difference is the main winding and the start winding separated in a spilt phase capacitor start induction motor?

a. 45° electrical
b. 90° electrical
c. 45° mechanical
d. 90° mechanical
Answer  Explanation 

ANSWER: 90° electrical

Explanation:
No explanation is available for this question!


2)   Which among these is the application of universal motors?

a. Vacuum cleaners
b. Fans
c. Hair dryers
d. Washing machines
Answer  Explanation 

ANSWER: Vacuum cleaners

Explanation:
No explanation is available for this question!


3)   What is the typical value of the capacitor used in ‘capacitor start capacitor run’ induction motor?

a. 5 μ F
b. 40 μ F
c. 300 μ F
d. 1000 μ F
Answer  Explanation 

ANSWER: 300 μ F

Explanation:
No explanation is available for this question!


4)   What is the value of the permanently connected capacitor in capacitor start capacitor run induction motor?

a. 40 μ F
b. 5 μ F
c. 300 μ F
d. 1000 μ F
Answer  Explanation 

ANSWER: 40 μ F

Explanation:
No explanation is available for this question!


5)   At what percentage of the rated speed is the starting winding of a capacitor start induction disconnected with the help of a centrifugal switch?

a. 50 % of the rated speed
b. 70 % of the rated speed
c. 25 % of the rated speed
d. 5 % of the rated speed
Answer  Explanation 

ANSWER: 70 % of the rated speed

Explanation:
No explanation is available for this question!


6)   What is the speed range of poly phase Commutator motors?

a. 0.5 Ns to 1 Ns
b. 0.5 Ns to 1.5 Ns
c. 0.1 Ns to 2 Ns
d. 0.5 Ns to 2.5 Ns
Answer  Explanation 

ANSWER: 0.5 Ns to 1.5 Ns

Explanation:
No explanation is available for this question!


7)   Which among these is an application of single phase synchronous AC motor?

a. Small drill
b. Large drill
c. Dishwasher
d. Sewing machine
Answer  Explanation 

ANSWER: Dishwasher

Explanation:
No explanation is available for this question!


8)   Which method is used for obtaining starting torque in a single phase induction motor?

a. Resistance split phase starting
b. Capacitor start capacitor run
c. Permanent split capacitor motor
d. Only a and c
e. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


9)   Which type of rotor is used for single phase induction motor?

a. Wound rotor
b. Squirrel cage rotor
c. Both (A) & (B)
d. None of these
Answer  Explanation 

ANSWER: Squirrel cage rotor

Explanation:
No explanation is available for this question!


10)   Which among these are the types of single phase AC motors?

i. Induction
ii. Shaded pole
iii. Synchronous
iv. Universal


a. i & ii only
b. ii, iii & iv only
c. i, ii, iii & iv
d. ii & iii only
Answer  Explanation 

ANSWER: i, ii, iii & iv

Explanation:
No explanation is available for this question!