Two concentric, circular wire loops, of radii $r_{1}=20.0 \mathrm{~cm}$ and $r_{2}=30.0 \mathrm{~cm}$, are located in an $x y$ plane; each carries a clockwise current of $7.00 \mathrm{~A}$ (Fig. $28-48$ ). (a) Find the magnitude of the net magnetic dipole moment of the system.
(b) Repeat for reversed current in the inner loop.