Problem 3.274

The magnetic induction in vacuum at a plane surface of a magnetic is equal to $B$ and the vector $B$ forms an angle $\theta$ with the normal $\mathrm{n}$ of the surface (Fig. 3.74$)$. The permeability of the magnetic is equal to $\mu .$ Find: (a) the flux of the vector $\mathbf{H}$ through the spherical surface $S$ of radius $R,$ whose centre lies on the surface of the magnetic; (b) the circulation of the vector $\mathbf{B}$ around the square path $\Gamma$ with side $l$ located as shown in the figure.