Power factor and three-phaseQuestion 1066 of 1506

Which harmonic class has no rotation because the three phases are in phase?

  1. Zero sequence (triplen)
  2. Positive sequence
  3. Negative sequence
  4. Fundamental sequence
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Correct answer: Zero sequence (triplen)

The 3rd and 9th harmonics are examples.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 7.8: Harmonic Phase Sequences

Practice power factor and three-phase

Questions last reviewed: 18 October 2026