ampere (A) /am″pēr/ [André-Marie Ampère, French physicist, 1775–1836] , a unit of measurement of the amount of electric current. An ampere, according to the meter-kilogram-second (MKS) system, is the amount of current passed through a resistance of 1 ohm by an electric potential of 1 volt; in the International System (SI) of Units, an ampere is a unit of electric current that carries a charge of 1 coulomb through a conductor in 1 second. The standard international ampere is the amount of current that deposits 0.001118 g of silver per second when passed, according to certain specifications, through a silver nitrate solution. See also ohm, volt, watt.