Volt is a unit of electrical measurement. The volt measures the ability of an electric field to give energy to electric charges. An electric field is the influence that an electric charge creates in the region around it. The field exerts forces on other charges in the region.
An electric field supplies energy to a charge if the charge moves between two points. The amount of energy divided by the charge is known as the potential difference, or voltage, between the two points. The volt is the unit used to measure this quantity. The potential difference is 1 volt when the field supplies 1 joule of energy to 1 coulomb of charge. One coulomb is the charge that flows through a wire in 1 second when the electric current is 1 ampere. A potential difference of 1 volt supplies enough energy to push 1 ampere of current through an electrical resistance of 1 ohm. A 1.5-volt flashlight battery, for example, supplies 1.5 joules of energy to each coulomb of charge that flows through an electric circuit.
The volt was named for the Italian scientist Alessandro Volta. Its symbol is V.
