Red Seal Electrician Practice
TransformersQuestion 1138 of 1506

What happens to the secondary waveform when a transformer core saturates?

  1. The frequency doubles.
  2. The voltage becomes pure DC.
  3. The waveform is distorted and has harmonics.
  4. The secondary current stops.
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Correct answer: The waveform is distorted and has harmonics.

A saturated core does not follow the primary waveshape, so harmonics appear in the output.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 10.8: Practical Considerations - Transformers

Practice transformers

Questions last reviewed: 18 October 2026