The figure shows, in cross section, four thin wires that are
parallel, straight, and very long. They carry identical currents of
i = 3.90 A in the directions indicated. Initially all four wires
are at distance d = 11.8 cm from the origin of the coordinate
system, where they create a net magnetic field ModifyingAbove Upper
B With right-arrow. (a) To what value of x must you move wire 1
along the x axis in order to rotate ModifyingAbove Upper B With
right-arrow counterclockwise by 30°?