Two concentric, circular wire loops, of radii $r_{1}=20.0 \mathrm{~cm}$ and $r_{2}=$ $40.0 \mathrm{~cm}$, are located in an $x y$ plane; each carries a clockwise current of 11.0 A (Fig. 28-26). (a) Find the magnitude of the net magnetic dipole moment of the system. (b) Repeat for reversed current in the inner loop.