rectangular loop a current i flows in a rectangular loop of wire placed on the y plane and centered about the origin. the length of the two sides are a and b (a) find the magnetic field at any location (0,0, 2) on the z-axis. (b) for za, b, what does your expression simplify to? (c) compare your answer to (b) with the on-axis field for a circular loop at distances much greater than the loop radius z. three parallel wires consider three co-planar equally-spaced (by distance d) parallel wires of negligible radius. each wire carries current i, a in the same direction (a) where does the magnetic field vanish? (b) sketch the magnetic field nes in the plane perpendicular to the current flow e) suppose you displace the middle wire a sinall distance δ in a direction perpendicular to the plane containing the wires and then release it. analyze and describe the resulting motion of the middle wire