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A sine wave has an RMS voltage of 120 volts. What is its peak-to-peak voltage?

339.4 volts peak-to-peak.

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  1. 84.8 volts
  2. 339.4 volts ✔
  3. 240.0 volts

Why: Peak is RMS times 1.414, which is about 169.7 volts. Peak-to-peak spans the negative peak to the positive peak, so double that: 339.4 volts.

Huh, didn't know that: Going the other way, a sine wave of 17 volts peak has an RMS value of about 12 volts.

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References

Answer: 339.4 volts. Peak is RMS times 1.414, which is about 169.7 volts. Peak-to-peak spans the negative peak to the positive peak, so double that: 339.4 volts.

  1. NCVEC 2023-2027 General Class Pool and Syllabus (6th Errata, Feb 4 2026) ncvec.org/downloads/General%20Class%20Pool%20and%20Syllabus%202023-2027%20Public%20Release%20with%206th%20Errata%20Feb%204%202026.pdf
    339.4 volts
    Checked 2026-10-11.

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