What is the peak value of a 120V circuit?

To determine the peak value of a 120V circuit, it is important to understand the relationship between the root mean square (RMS) voltage and the peak voltage in an alternating current (AC) system.

In AC circuits, the RMS voltage is the value that represents the effective voltage—that is, it provides the same power as a DC voltage. The RMS voltage for a sine wave can be calculated from the peak voltage using the formula:

[ \text{Peak Voltage} = \text{RMS Voltage} \times \sqrt{2} ]

Given that the RMS voltage of the circuit is 120V, you can calculate the peak voltage as follows:

[ \text{Peak Voltage} = 120V \times \sqrt{2} \approx 120V \times 1.414 \approx 169.7V ]

This rounds to approximately 170V, which indicates that the peak value for a 120V circuit is indeed around 170V. Therefore, this understanding leads to the conclusion that the correct peak value is 170V.

The options provided illustrate different common values, but only the option of 170V reflects a proper calculation based on the established mathematical relationship between RMS and peak voltage in