Power factor - Electrical Engineering (MCQ) questions and answers

1)   A synchronous motor takes the leading current when it is

a. Overexcited
b. Under excited
c. Not excited
d. Either (a) or (b)
e. All of these
Answer  Explanation 

ANSWER: Either (a) or (b)

Explanation:
No explanation is available for this question!


2)   For voltage boosting in distribution networks the capacitors used is

a. Series capacitors
b. Shunt capacitors
c. Both (a) and (b)
d. None of these
Answer  Explanation 

ANSWER: Series capacitors

Explanation:
No explanation is available for this question!


3)   To reduce the power consumption, the capacitors should be located

a. As close as possible to the load
b. As far as possible to the load
c. Not too close not too far from the load
d. All of these
e. None of these
Answer  Explanation 

ANSWER: As close as possible to the load

Explanation:
No explanation is available for this question!


4)   If an alternator is supplying load of 350 kW at 0.6 pf lagging and its power factor is raised to unity then to supply the alternator for the same kVA loading, the extra required kilowatts will be

a. 205 kW
b. 212 kW
c. 233 kW
d. 246 kW
Answer  Explanation 

ANSWER: 233 kW

Explanation:
No explanation is available for this question!


5)   In order to improve the power factor of equipment operating at lagging power factor, a capacitor is connected

a. In series with the equipment
b. In parallel with the equipment
c. In series-parallel with the equipment
d. Either (a) or (b)
Answer  Explanation 

ANSWER: In parallel with the equipment

Explanation:
No explanation is available for this question!


6)   Phase advancers are used to improve the power factor of

a. Induction motors
b. Induction generators
c. Synchronous motors
d. Synchronous generators
Answer  Explanation 

ANSWER: Induction motors

Explanation:
No explanation is available for this question!


7)   Power factor of a load can be improved by using

a. Static capacitors
b. Synchronous condenser
c. Phase advancer
d. Only a and b
e. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!


8)   If power factor is less than unity then it will result in

a. Large kVA rating of equipment
b. Greater conductor size
c. Large copper losses
d. Only A and C
e. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


9)   If the load current decreases then the power factor

a. Will also decrease
b. Will increase
c. Will remains unchanged
d. None of these
Answer  Explanation 

ANSWER: Will increase

Explanation:
No explanation is available for this question!


10)   The wattles component is

a. I
b. I cos∅
c. I sin∅
d. None of these
Answer  Explanation 

ANSWER: I sin∅

Explanation:
No explanation is available for this question!