Question

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

Answer 1

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