What is the peak-to-peak voltage of a sine wave that has an RMS voltage of 120 volts?

To find the peak-to-peak voltage from an RMS voltage, you must perform a two-step calculation. First, convert the RMS voltage to peak voltage by multiplying it by the square root of 2 (approximately 1.414). For 120 volts RMS, the peak voltage is 120 × 1.414 = 169.7 volts. Next, because a sine wave alternates between positive and negative peaks, the peak-to-peak voltage is exactly twice the peak voltage. Multiplying 169.7 volts by 2 gives 339.4 volts, which perfectly matches the 339.5 volts option when accounting for slight rounding variations of the square root of 2.