Red Seal Electrician Practice
Power factor and three-phaseQuestion 1195 of 1506

What can harmonics do to an electric motor?

  1. Raise its output without limit
  2. Lower its speed to zero
  3. Change its direction
  4. Reduce its horsepower output
Show answer

Correct answer: Reduce its horsepower output

Harmonic content is one cause of reduced motor output.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 12.4: Power Quality Measurement

Practice power factor and three-phase

Questions last reviewed: 18 October 2026