A small loop of wire of radius a lies a distance d from the center of a large loop of radius b. The planes of the two loops are parallel and perpendicular to the common axis.
(a) Suppose current I flows in the big loop. Find the flux through the small loop (consider the field in the vicinity of the small loop constant).
(b) Suppose current I flows in the small loop. Find the flux through the big loop (consider the small loop as a magnetic dipole).
(c) Find the mutual condustances and confirm that M12 = M21.