The volt (symbol: V) is the SI derived unit for electric potential (voltage), electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta, who invented the voltaic pile, possibly the first chemical battery.
A single volt is defined as the difference in electric potential across a wire when an electric current of one ampere dissipates one watt of power. It is also equal to the potential difference between two parallel, infinite planes spaced 1 meter apart that create an electric field of 1 newton per coulomb. Additionally, it is the potential difference between two points that will impart one joule of energy per coulomb of charge that passes through it. It can be expressed in terms of SI units as follows:
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