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 metre apart in vacuum, would produce between these conductors a force equal to ${2 \times 10^{-7}}$ newton per metre of length.
Unit | ampere |
---|---|
Symbol | A |
Quantity | electric current |
Defining Resolution |
CGPM Resolution 2 (1948) |
Unit Type | SI base unit |