Information AboutVolt |
| CATEGORIES ABOUT VOLT | |
| si derived units | |
| units of electrical potential | |
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The volt (symbol: V) is the SI Derived Unit of electric Potential Difference or Voltage . It is named in honor of the Italian Physicist Alessandro Volta (1745–1827), who invented the Voltaic Pile , the first chemical Battery . DEFINITION The volt is defined as the Potential Difference across a conductor when a Current of one Ampere dissipates one Watt of Power . Hence, it is the base SI representation M 2 · Kg · S -3 · A -1, which can be equally represented as one Joule of Energy per Coulomb of charge, J/C. :1 V = 1 W/A = 1 J/C = 1 m2·kg·s–3·A–1 Since 1990 the volt is maintained internationally for practical measurement using the Josephson Effect , where a conventional value is used for the Josephson Constant , fixed by the 18th General Conference On Weights And Measures as :K{J-90} = 0.4835979 GHz/µV. COMMON VOLTAGES Nominal voltages of familiar sources:
HISTORY OF THE VOLT In 1800, as the result of a professional disagreement over the galvanic response advocated by Luigi Galvani , Alessandro Volta developed the so-called Voltaic Pile , a forerunner of the Battery , which produced a steady electric Current . Volta had determined that the most effective pair of dissimilar metals to produce electricity was Zinc and Silver . In the 1880s, the International Electrical Congress , now the International Electrotechnical Commission (IEC), approved the volt for electromotive force. The volt was defined as the potential difference across a conductor when a current of one Ampere dissipates one Watt of power. Prior to the development of the Josephson junction voltage standard, the volt was maintained in national laboratories using specially constructed batteries called standard cells. The United States used a design called the Weston Cell from 1905 to 1972. NOTES |
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