Slip of an induction motor is negative when_____________?
Correct answer: C. rotor speed is more than the synchronous speed of the field and are in the same direction
- A. magnetic field and rotor rotate in opposite direction
- B. rotor speed is less than the synchronous speed of the field and are in the same direction
- C. rotor speed is more than the synchronous speed of the field and are in the same direction
- D. none of the above
Explanation
Slip is defined as s = (N_s − N_r)/N_s, so it becomes negative when the rotor runs faster than the rotating magnetic field. The rotor and field must still rotate in the same direction.
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