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
Volta potential electrostatic potentials, but instead the difference in Fermi level between the two materials, a difference that is exactly zero at equilibrium. The Volta potential however corresponds to a real electric field in the spaces between and around the two metal objects, a field generated by the accumulation of charges at their surfaces. The total charge formula_2 over each objects' surface depends on the capacitance formula_3 between the two objects, by the relation formula_4 where formula_5 is the Volta potential. It follows therefore that the value of the potential can be measured by varying the capacitance between the materials by a