Red Seal Electrician Practice
MotorsQuestion 225 of 1506

What is a weakness of controlling a wound rotor motor’s speed with rotor resistance?

  1. Speed changes a lot as the load changes
  2. The speed can never be lowered at all
  3. The motor then needs no slip rings
  4. The motor can no longer start under load
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Correct answer: Speed changes a lot as the load changes

With resistance in the rotor, the speed regulation is poor for changing torque loads.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 13.8: Wound Rotor Induction Motors

Practice motors

Questions last reviewed: 18 October 2026