What value of an AC signal produces the same power dissipation in a resistor as a DC voltage of the same value?

The Root Mean Square (RMS) value of an alternating current (AC) signal is specifically defined as the amount of AC that produces the exact same heating effect (power dissipation) in a resistor as a direct current (DC) of the same value. Because an AC signal is constantly changing in amplitude and spends much of its cycle below its peak value, its effective power-producing capability is lower than its maximum voltage. For a standard sine wave, this effective, or RMS, value is approximately 70.7 percent of the peak value. This makes RMS the standard way to measure AC voltages so they can be directly compared to DC voltages.