Power factor of a synchronous motor is unity when_____________?
Correct answer: B. the armature current is minimum
- A. the armature current is maximum
- B. the armature current is minimum
- C. the armature current is zero
- D. none of the above
Explanation
The synchronous motor has unity power factor at the minimum point of its V-curve, where the armature current is minimum. Underexcitation causes lagging current, while overexcitation causes leading current.
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