RMS Current
The Root-Mean-Square value of an alternating current (AC), representing the equivalent direct current (DC) that delivers equal average heating power to a resistor.
Governing formula
I_rms = I_peak / √2 ≈ 0.707 I_peak
SI unit
A (Amperes)
In depth
AC ammeters and voltmeters are calibrated to display RMS values. Standard residential 120 V AC electricity has a peak voltage amplitude of ~170 V (120 × √2).
Examples in the real world
A 10 A RMS AC current generating identical resistive Joule heating in a water heater element as a steady 10 A DC current.