SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/hamg-g5b07

Which AC value heats a resistor the same as a DC voltage of equal value?

The RMS value gives equal power dissipation.

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  1. The RMS value ✔
  2. The peak-to-peak value
  3. The peak value

Why: RMS stands for root mean square. An AC source of 120 volts RMS heats a resistor just like 120 volts DC. Peak values of a sine wave are higher than the RMS value.

Huh, didn't know that: An incandescent bulb glows equally bright on 120 volts DC or 120 volts RMS AC.

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References

Answer: The RMS value. RMS stands for root mean square. An AC source of 120 volts RMS heats a resistor just like 120 volts DC. Peak values of a sine wave are higher than the RMS value.

  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
    The RMS value
    Checked 2026-10-11.

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