ampere
(A or amp)
the SI base unit of electric current, named for the French physicist André-Marie Ampère (1775-1836), one of the pioneers in studying electricity. The current official definition of the ampere goes like this: suppose we have two parallel conductors, infinitely long and having negligible cross section. Place these conductors one meter apart in a perfect vacuum. One ampere is the current which, if it's flowing in these conductors, creates between them a force of 0.2 micronewtons per meter of length. (You're welcome to object that no one can make an infinitely long conductor, nor a perfect vacuum. But scientists can use the idealized definition to construct appropriate real-world equipment in their laboratories.) It is likely that new definitions will be adopted at the CGPM meeting in 2011; the proposed definition is that the ampere represents a flow of exactly 6 241 509 479 607 717 888 elementary charge units (such as electrons) per second. The other electrical units are all defined in terms of the ampere. For example, one ampere represents a current flow of one coulomb of charge per second. One ampere of current results from a potential distribution of one volt per ohm of resistance, or from a power production rate of one watt per volt of potential. The unit is known informally as the amp, but A is its official symbol.

Dictionary of units of measurement. 2015.

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• ampère — [ ɑ̃pɛr ] n. m. • 1865; de Ampère, nom d un physicien ♦ Unité d intensité des courants électriques, qui correspond à un écoulement de un coulomb par seconde dans un conducteur (symb. A). Ampère par mètre (symb. A/m) :unité d intensité de champ… …   Encyclopédie Universelle

• Ampere — Ampère Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. Ampère peut désigner : André Marie Ampère (1775 1836), physicien français. Son nom a été donné à : l’ampère, unité SI d’intensité d’un… …   Wikipédia en Français

• Ampere —     André Marie Ampère     † Catholic Encyclopedia ► André Marie Ampère     Physicist and mathematician, b. 22 January, 1775, at Lyons, France; d. at Marseilles, 10 June, 1836. His father was a prosperous and educated merchant, his mother… …   Catholic encyclopedia

• Ampère — can refer to: *Ampère (car) *Ampere (unit) *André Marie Ampère, one of the main discoverers of electromagnetism *Ampere (band) …   Wikipedia

• Ampère — ampere (de «A. M. Ampère», físico francés) m. Fís. Amperio, en la nomenclatura internacional. * * * ampere. (De A. M. Ampère, 1775 1836, matemático y físico francés). m. Fís. amperio. * * * …   Enciclopedia Universal

• Ampère — (Париж,Франция) Категория отеля: 4 звездочный отель Адрес: 102 Avenue de Villiers, 17 й округ …   Каталог отелей

• Ampère — (spr. angpǟr ), 1) André Marie, Physiker und Mathematiker, geb. 22. Jan. 1775 in Lyon, gest. 10. Juni 1836 in Marseille, studierte Chemie und Physik, erhielt 1801 eine Professur in Bourg, ging von dort nach Lyon und 1805 nach Paris und ward 1809… …   Meyers Großes Konversations-Lexikon

• ampere — (de «A. M. Ampère», físico francés) m. Fís. Amperio, en la nomenclatura internacional. * * * ampere. (De A. M. Ampère, 1775 1836, matemático y físico francés). m. Fís. amperio. * * * ► masculino METR …   Enciclopedia Universal

• ampere — (n.) 1881, the current that one volt can send through one ohm, from Fr. ampère, named for French physicist André Marie Ampère (1775 1836). Shortened form amp is attested from 1886 …   Etymology dictionary

• Ampere — Am p[ e]re ([aum]N p[^a]r ), Ampere Am*pere ([a^]m*p[=a]r ), n. [From the name of a French electrician.] (Elec.) The unit of electric current; defined by the International Electrical Congress in 1893 and by U. S. Statute as, one tenth of the unit …   The Collaborative International Dictionary of English

• Ampere — Am p[ e]re ([aum]N p[^a]r ), Ampere Am*pere ([a^]m*p[=a]r ), n. [From the name of a French electrician.] (Elec.) The unit of electric current; defined by the International Electrical Congress in 1893 and by U. S. Statute as, one tenth of the unit …   The Collaborative International Dictionary of English

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