A toroid of n turns, mean radius R

A toroid of n turns, mean radius R and cross-sectional radius a carries current I. It is placed on a horizontal table taken as an x-y plane. Its magnetic moment m

(a) is non-zero and points in the z-direction by symmetry

(b) points along the axis of the toroid

$m=m \hat{\phi}$

(c) is zero, otherwise, there would be a field falling as 1/r3 at large distances outside the toroid

(d) is pointing radially outwards