Ampage

Ampage

The ampere ( AM-pair, US: AM-peer; symbol: A), often shortened to amp, is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 coulomb, or 6.241509074×1018 electrons' worth of charge, moving past a point in a second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagnetism along with Danish physicist Hans Christian Ørsted. As of the 2019 redefinition of the SI base units, the ampere is defined by fixing the elementary charge e to be exactly 1.602176634×10−19 C (coulomb), which means an ampere is an electric current equivalent to 1019 elementary charges moving every 1.602176634 seconds or 6.241509074×1018 elementary charges moving in a second. Prior to the redefinition the ampere was defined as the current passing through 2 parallel wires 1 metre apart that produces a magnetic force of 2×10−7 newtons per metre. The earlier CGS system has two units of current, one structured similar to the SI's and the other using Coulomb's law as a fundamental relationship, with the unit of charge defined by measuring the force between two charged metal plates. The unit of current is then defined as one unit of charge per second. In SI, the unit of charge, the coulomb, is defined as the charge carried by one ampere during one second.

Update this biography »
Complete biography of Ampage »