\documentstyle[12pt]{article}
\begin{document}
\begin{center}
{\Huge Maxwell's Equations}
\end{center}
\vspace{2 eM}
\begin{Large}

\[ \oint \vec{E} \cdot \hat{n} dS = \frac{Q _{free}}{\varepsilon _{0}
\kappa} \]

\[ \oint \vec{B} \cdot \hat{n} dS = 0 \]

\[ \oint \vec{E} \cdot d\vec{\ell} = \frac{- d \Phi _B}{dt} \]

\[ \oint \vec{B} \cdot d\vec{\ell} = \mu _0 \kappa _m (I + \varepsilon _0
\kappa \frac{d \Phi _E}{dt}) \]

\end{Large}
\end{document}