Red Seal Electrician Practice
AC theoryQuestion 1054 of 1506

What does a nonlinear load do to the line current?

  1. It keeps the current a pure sine wave
  2. It lowers the frequency
  3. It distorts the wave and adds harmonics
  4. It makes the current DC
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Correct answer: It distorts the wave and adds harmonics

Any distortion of a sine wave means that harmonic frequencies are present.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 7.7: Harmonics in Polyphase Power Systems

Practice ac theory

Questions last reviewed: 18 October 2026