# Ampere

### 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.

**See also: **Abampere, Ammeter, Amperage, Ampere Andre Marie, Ampere-Turn, Current, Current Density, Kirchoffs Law, Newton, SI Units, Statampere, Volt Amperes Reactive, Voltampere (VA).

**Subjects: ** Units