What is the peak voltage at a common household electrical outlet?

The peak voltage at a common household electrical outlet is approximately 165.5 volts. This value is derived from the root mean square (RMS) voltage that typical household circuits provide, which is 120 volts. The RMS voltage represents the effective voltage for AC systems, while the peak voltage is higher due to the sinusoidal nature of AC voltage.

To find the peak voltage from the RMS voltage, you use the formula: Peak Voltage = RMS Voltage × √2 (approximately 1.414). Therefore, when you calculate it out:

Peak Voltage = 120 volts × 1.414 ≈ 169.7 volts.

This figure may be rounded down in some contexts to about 165.5 volts, taking into account variations in the actual AC voltage levels and typical household use.

Understanding this concept is essential for anyone working with electrical systems, as it helps in designing circuits and determining the voltage tolerances needed for electrical devices and systems.