The back e.m.f. in the stator of a synchronous motor depends on____________?
Correct answer: D. rotor excitation
- A. number of poles
- B. flux density
- C. rotor speed
- D. rotor excitation
- E. none of the above
Explanation
The synchronous motor’s back emf is produced by the rotor field, so it varies primarily with rotor excitation or field current. At fixed supply frequency, rotor speed is fixed and does not independently control the back emf.
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