Power System - I (3140914) MCQs

MCQs of Power Factor and Power Factor Improvement of Load

Showing 11 to 10 out of 20 Questions
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11.
For power factor improvement static capacitors have the advantage of
(a) Small losses
(b) Easy installation
(c) Low initial cost and little maintenance
(d) All of above
Answer:

Option (d)

12.
For power factor improvement by static capacitors have the drawback of
(a) Short service life
(b) Getting damaged by high voltage
(c) Not repairable
(d) All of above
Answer:

Option (d)

13.
A synchronous condenser is virtually
(a) Induction motor
(b) Over excited synchronous motor
(c) Under excited synchronous motor
(d) Commutator motor
Answer:

Option (b)

14.
Power factor improvement by synchronous condenser have drawback of
(a) Comparatively higher maintenance and operating cost
(b) Requirement of auxiliary equipment for starting
(c) Possibility of falling out of synchronism causing in interruption of supply
(d) All of above
Answer:

Option (d)

15.
Advantage of improved power factor is
(a) Increase in operating efficiency of power system
(b) Improvement in voltage regulation
(c) Reduction in overall cost per unit
(d) Better utilization of kW capacity of prime movers, transformers, switchgears and line
Answer:

Option (d)

16.
The most suitable location of a power factor improvement device is
(a) Near the electrical appliances which is responsible for poor power factor
(b) At the receiving end in case of transmission line
(c) At the sending end
(d) Both (a) and (b)
Answer:

Option (d)

17.
An industrial installation has a power factor of 0.8 lagging. It would be economical to improve power factor to
(a) Unity
(b) About 0.8 leading
(c) About 0.95 lagging
(d) About 0.95 leading
Answer:

Option (c)

18.
3 phase, 11 kV, 50 Hz, 200 kW  load has a power factor of 0.8 lagging. A delta connected 3 phase capacitor is used to improve power factor to unity. Capacitance per phase of the capacitor in μF is
(a) 3.948
(b) 1.316
(c) 0.439
(d) 11.844
Answer:

Option (d)

19.
The most economical limit of power factor correction  is governed by
(a) Original power factor
(b) Relative cost of supply and power factor correction equipment
(c) Both (a) and (b)
(d) Neither (a) or (b)
Answer:

Option (b)

20.
There is a limit beyond which it is not economical still further to improve the power factor in order to meet the increased demand on the generating station. The maximum value to which the power factor can be economically raised entirely depends upon
(a) Cost of power factor correction equipment
(b) Cost of generating plant
(c) Relative cost of the generating plant and phase advancing plant
(d) None of above
Answer:

Option (c)

Showing 11 to 10 out of 20 Questions
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