Using the concept of force between two infinitely long parallel current carrying conductors, define one ampere of current.

The amount of current flowing in the same direction through two infinitely long parallel wires separated by one metre produces an attractive force of 2 × 10⁻⁷ N/m, provided the wires have negligible circular cross-section and are placed in a vacuum. This flowing current can be defined as "One Ampere of Current".