Figure 22.115 shows a large number N of closely packed wires, each carrying a current I out of the page. The width of this sheet of wires is L.
(a) Show (and explain) the direction of the magnetic field at the two indicated locations, a distance d from the middle
wire, where d is much less than L(d
(b) Using the rectangular path shown on the diagram, calculate the magnitude of the magnetic field at the indicated
locations, in terms of the given physical quantities N, I, and L.
(c) Using your result from part (b), find in the region between two parallel current sheets with equal currents
running in opposite directions.
(d) What is outside both sheets?