Consider two circular loops of wire, radius R1 and R2, which both lie in the xy plane and are centered at the origin. Current I1 runs around R1 and current I2 runs around R2, with positive current indicating counterclockwise current and negative clockwise. Explain how this system could be a model for a magnetic quadrupole, and derive any needed condition on the parameters for the quadrupole to be the lowest non-zero multipole