What is the common voltage in residential electrical systems?

Residential electrical systems in the United States commonly operate at 120 volts. This standard voltage is primarily used for most household electrical outlets and lighting fixtures. The 120-volt system is designed to safely power typical household appliances and devices, ensuring compatibility and efficiency in residential electrical use.

While 240 volts are used for larger appliances like dryers, ovens, and HVAC systems, the fundamental voltage supplied to the majority of outlets in residential settings remains at 120 volts. This is supported by infrastructure and safety regulations that dictate wiring and circuit designs to ensure safe and reliable power distribution in homes.

The options of 300 volts and 480 volts are not typically found in residential contexts. These voltages are more common in industrial settings or specific specialized applications, where higher voltage is necessary to power heavy machinery or equipment. Thus, the established norm for residential electrical systems is centered around the 120-volt supply, making it the correct choice.