A unit of electric current in the meter-kilogram-second system. It is the steady current that when flowing in straight parallel wires of infinite length and negligible cross section, separated by a distance of one meter in free space, produces a force between the wires of 2 × 10-7 newtons per meter of length.
The practical meter-kilogram-second unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm.
The base unit of electric current in the International System of Units that is equal to a constant current which when maintained in two straight parallel conductors of infinite length and negligible circular sections one meter apart in a vacuum produces between the conductors a force equal to 2 × 10 newton per meter of length.
The basic unit of electric current, equal to one coulomb per second and equivalent to the current, flowing in two straight parallel wires of negligible cross section separated by a distance of one meter, that produces a force between the wires of 2.0 × 10-7 newtons per meter of length. The value of an ampere in the International System differs very slightly from that in the meter-kilogram-second-ampere system of units.