What is the RMS value of a 340-volt peak-to-peak pure sine wave?

To determine the RMS (Root Mean Square) value of a peak-to-peak voltage for a pure sine wave, you first need to convert the peak-to-peak voltage into the peak voltage. The peak voltage is half of the peak-to-peak voltage. Therefore, for a 340-volt peak-to-peak sine wave, the peak voltage is:

Peak Voltage = Peak-to-Peak Voltage / 2 = 340 V / 2 = 170 V

Knowing that the RMS value of a sine wave is calculated by taking the peak voltage and dividing it by the square root of 2, you can compute the RMS value:

RMS Voltage = Peak Voltage / √2 = 170 V / 1.414 ≈ 120 V

Thus, the RMS value of a 340-volt peak-to-peak pure sine wave is approximately 120 volts AC, which corresponds to the chosen answer. This relationship holds true because the RMS value provides a measure of the effective value of the alternating current (AC) voltage, delivering the same power to a resistive load as a comparable direct current (DC) voltage would.