Figure` 29-62` shows, in cross section, four thin wires that are parallel, straight, and very long. They carry identical currents in the directions indicated. Initially all four wires are at distance `d=15.0` cm from the origin of the coordinate system, where they create a net magnetic field `vecB`.
(a) To what value of `x` must you move wire`1`along the `x` axis in order to rotate`vecB` counterclockwise by `30^(@)`?
(b) With wire `1` in that new position, to what value of `x`must you move wire `3` along the `x` axis to rotate `vecB` by `30^(@)` back to its initial orientation ?

Answer

`(a)-7.0cm; (b)+7.0cm`