When the field of a synchronous motor is under-excited, the power factor will be____________?
Correct answer: B. lagging
- A. leading
- B. lagging
- C. unity
- D. zero
Explanation
An under-excited synchronous motor draws a lagging current to obtain the required magnetizing ampere-turns. Therefore, its power factor is lagging; over-excitation would produce a leading power factor.
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