What type of electrical current is typically used in residential wiring?

Residential wiring commonly utilizes alternating current (AC) because it is more efficient for the transmission of electricity over long distances. AC can easily transform between high voltages for transmission, minimizing energy loss, and lower voltages for safe use in homes. The ability to change voltage levels is particularly advantageous when electricity is distributed from power plants to homes, allowing for reduced loss of power due to resistance in wires.

Direct current (DC), while important in some applications such as battery-powered devices and electronics, is not practical for general residential power supply due to difficulties in voltage conversion and longer transmission distances. High voltage alternating current is typically used in transmission lines but not within residential wiring, where voltage levels are much lower for safety and usability. Variable current is not a standard terminology in electricity and does not accurately describe a specific type of current used in residential settings.