Meters and troubleshootingQuestion 1196 of 1506

An averaging meter and a true-RMS meter read the same voltage. The two readings differ greatly. What does this show?

  1. The meters are both correct and the wave is clean.
  2. The frequency is below 60 Hz.
  3. The system is unloaded.
  4. The waveform has a high harmonic content.
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Correct answer: The waveform has a high harmonic content.

An averaging meter is calibrated for sine waves. A large difference points to a distorted wave and poor power quality.

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

Practice meters and troubleshooting

Questions last reviewed: 18 October 2026