The different currents in four long straight wires are shown below, along with the positions P, Q, R, and S at various perpendicular distances from each wire.

![Four upright parallel wires are shown on a grid with upward-pointing arrows indicating current direction. From top to bottom:

• The first wire carries a current of 2 A. Position P is to its right at a distance of 1 unit.
• The second wire carries a current of 6 A. Position Q is to its right at a distance of 3 units.
• The third wire carries a current of 1 A. Position R is to its right at a distance of 2 units.
• The fourth wire carries a current of 8 A. Position S is to its right at a distance of 2 units.](https://assets.mathsgenie.co.uk/aqa-qb/225faa35-7c5c-4235-be07-e5e56ae17642.png)

Which position will experience the weakest magnetic field?