Voltage across the inductor's terminals. This is the reason that measurements with a voltmeter across an inductor are often reasonably independent of the placement of the test leads. The volt (symbol: ) is the derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honour of the Italian physicist Alessandro Volta (1745–1827), who invented the voltaic pile, possibly the first chemical battery. A simple analogy for an electric circuit is water flowing in a closed circuit of pipework, driven by a mechanical pump. This can be called a "water circuit". Potential difference between two points
John Read (inventor) after his death. John Read (inventor) John Read was a British physicist and inventor. He developed a rotating doubler electrostatic generator, used to produce static electricity, which he called a 'spectacle doubler' because it involved discs of glass. His work was based on William Nicholson's doubler. Reid lived in Knightsbridge, London and taught at the Knightsbridge Charity School. He made observations of the atmospheric electric field, which he observed behaved differently in different air quality conditions, in 1791 and 1792. This phenomenon is now understood as originating from the global electric circuit. Richard Lovett was the first British academic to