The SI unit of Electric current
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 a force between the conductors equal to 2x10-7 newton per metre of length.
The official symbol is A.
The other electrical units are all defined in terms of the ampere:
- One ampere represents a current flow of one coulomb of charge per second.
- One ampere of current results from a potential distribution of one volt per ohm of resistance.