(3%) (b)請問Magnetization vector M 為何?

(4%) (d) Using the result from a), along with the per unit length external inductance found in c), write down the internal & external inductance for the conductor system shown in the Right of Fig. 3.Fig. 3. A single conductor above a Ground (Left); A two-conductor system with currents flow in opposite direction (Right); the two conductors both with radius a and d distance apart.