Two circular current loops are located at z = +R/2 and z = ?R/2, parallel to the xy-plane and centered at the z-axis. Each loop has current i and radius R. Figure: https://s19.postimage.org/lu32fpvfn/Exam3_No9.jpg
(A) Derive a formula for the magnetic field at an arbitrary point on the z-axis. Note by symmetry that B(x) = Bz(z) k.
(B) Calculate the ratio Bz(R)/Bz(0).