What is the voltage standard for the United States as it applies to Alternating Current from a 3-prong Edison wall outlet?

The voltage standard for Alternating Current (AC) in the United States from a 3-prong Edison wall outlet is indeed 120 Volts AC. This is the common nominal voltage used for household electrical systems and appliances. The choice of 120 volts is significant because it strikes a balance between safety and efficiency for powering standard devices.

Historically, the 110 volts figure was often used, but it has been updated to 120 volts to match the actual voltage used in the electrical grid. This means that while 120 volts is the nominal voltage, the actual voltage may vary slightly, often ranging between 115 to 125 volts depending on load and other factors.

Other options, such as 220 volts and 240 volts, are typically associated with larger household appliances, such as dryers and ovens, which require a higher voltage supply to operate effectively. These voltages are not standard for general outlets, making them unsuitable answers for the question regarding a standard 3-prong Edison wall outlet.