When the stator windings are connected in such a fashion that the number of poles are made half, the speed of the rotor of a synchronous motor___________?
Correct answer: D. increases to two times the original value
- A. remains same as the original value
- B. decreases to half the original value
- C. tends to becomes zero
- D. increases to two times the original value
Explanation
Synchronous speed is Ns = 120f/P, so at unchanged frequency, halving the number of poles doubles the rotor speed. The rotor remains locked to this new synchronous speed.
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