If a circuit operates at 277 volts (RMS), what is the peak value of the voltage?

To determine the peak voltage from the RMS (Root Mean Square) voltage, you can use the relationship between these two values for an AC circuit. The formula to convert RMS voltage to peak voltage is:

Peak Voltage = RMS Voltage × √2.

In this case, the circuit operates at 277 volts RMS. To calculate the peak voltage:

Peak Voltage = 277 volts × √2 ≈ 277 volts × 1.4142 ≈ 391.8 volts.

Thus, the peak value of the voltage, which is approximately 391.8 volts, aligns with the provided choice. This conversion is essential for understanding the behavior of AC circuits where the peak voltage is higher than the RMS voltage, reflecting the true maximum voltage level present in the waveform.