Dictionary of Computer and Internet Terms: rms (root-mean-square)
rms (root-mean-square)
the most common method of measuring the voltage of an alternating current; the square root of the mean of the square of the instantaneous voltage. This method of measurement is used because power (wattage) depends on the voltage squared; thus, 120 volts AC rms will light a light bulb to the same brightness as 120 volts DC.With a sine wave, the rms voltage is 0.707×the peak voltage or 0.353 × the peak-to-peak voltage. Contrast peak; peak-to-peak.
