Ampere is named after the French physicist André-Marie Ampère from the 19th century and describes a movement of one coulomb of electricity per second. In a resistance of one ohm a flow of one ampere is created by a potential difference of one volt.

Ampere, unit of electric current used by both scientists and technologists in SI unit system. The General Conference on Weights and Measures (CGPM) decided in 2018 that the ampere will be specified in such a way that the elementary charge will be equivalent to 1.602176634 × 10−19 coulomb. Earlier the ampere was defined as the constant current which, if retained in two straight parallel conductors with an infinite length of negligible circular cross-section and placed one meter apart in a vacuum, would produce a force equivalent to 2×10−7 newtons per meter of length between these conductors.