Which wiring system uses two ungrounded conductors and one neutral conductor to provide power and light?

The three-wire, single-phase wiring system is designed to utilize two ungrounded conductors and one neutral conductor to deliver both power and lighting to circuits. In this setup, the two ungrounded conductors allow for a push-pull arrangement that can effectively provide 120V or 240V, depending on the appliance or lighting requirements. The neutral conductor serves as a return path for current and helps balance the system, ensuring that the two ungrounded conductors can operate in tandem without creating an unsafe situation.

This system is prevalent in residential and light commercial settings for its efficiency in supplying electrical power for various loads. It allows for the use of standard light fixtures, outlets, and other devices which typically expect a single-phase supply while facilitating flexibility in wiring configurations.

The other options involve different configurations. For example, the two-wire, single-phase option would typically include only one ungrounded conductor and one neutral, which would limit its applications primarily to low-power, light-duty circuits. The three-phase systems, like the three-phase, three-wire and three-phase, four-wire setups, are designed for higher loads and industrial applications, where three separate phases are necessary for powering larger equipment. Thus, they don't align with the specific wiring system that incorporates