ampere

https://doi.org/10.1351/goldbook.A00300
SI base unit for the @E01927@ (symbol: \(\text{A}\)). The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 @M03884@ apart in vacuum, would produce between these conductors a force equal to \(2\times 10^{-7}\) @N04135@ per @M03884@ of length (9th CGPM, 1948).
Sources:
Green Book, 2nd ed., p. 70 [Terms] [Book]
PAC, 1996, 68, 957. (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 961 [Terms] [Paper]