\begin{eqnarray*}
\newcommand{\bm}[1]{\boldsymbol{#1}}
\displaystyle \int_S div\bm{D}\cdot d\bm{s} &=& Q\\\displaystyle -\frac ddot{dt}\int_S \bm{B}\cdot d\bm{s} &=& V\rot \bm E\\
\displaystyle \oint_S \bm{H}\cdot d\bm{s} &=& I \\
(\iff 4\pi r^2d\bm{H} &=&