A synchronous motor installed at the receiving end substation operates with such an excitation that it takes power at lagging power factor. Now if the applied voltage of the synchronous motor goes down, the power factor of the synchronous motor will___________?
Correct answer: C. improve
- A. remain same
- B. go down
- C. improve
- D. none of the above
Explanation
With fixed excitation and load, reducing the terminal voltage makes an underexcited motor draw relatively less lagging reactive current, so its power factor moves closer to unity. Hence the lagging power factor improves.
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