\documentclass[crop,border=5,tikz,convert={outext=,
  command=\unexpanded{pdf2svg \infile\space\outfile\%02d.svg all}},multi=false]{standalone}

\usetikzlibrary{patterns}

\begin{document}
\begin{tikzpicture}[scale=0.75,>=stealth,rotate=0]
  \fill[gray!40] (-4,-1)rectangle(4,0);
  \fill[pattern,pattern = north east lines] (-4,-1) rectangle (4,0)
  node[black,midway,fill=white]{$\epsilon_r$};
  \draw[thick] (0,1) -- (0,2);
  \draw[thick] (0,-1) -- (0,-2);
  \draw[ultra thick] (-4,1)--(4,1) node[midway,above
  left]{$A$};
  \draw[ultra thick] (-4,-1) -- (4,-1);
  \draw[<->] (3,1)--(3,-1) node[midway,above left]{$d$};
  %\draw[<->] (-2,0)--(-2,1) node[midway,right]{$d/2$};
  \begin{scope}[shift={(9,0)},scale=0.75/2]
    \node at (-9,0){$\Longleftrightarrow$};
    \fill[gray!40] (-4,-2) rectangle (4,-1);
    \fill[pattern,pattern = north east lines] (-4,-2) rectangle (4,-1);
    \draw[thick] (0,3) -- (0,2);
    \draw[ultra thick] (-4,2) node[above left]{$C_1$} -- (4,2);
    \draw[ultra thick] (-4,1) -- (4,1);
    \draw[thick] (0,1) -- (0,-1);
    \draw[ultra thick] (-4,-1) -- (4,-1);
    \draw[ultra thick] (-4,-2) node[below left]{$C_2$} -- (4,-2);
    \draw[thick] (0,-3) -- (0,-2);
  \end{scope}
\end{tikzpicture}

\begin{tikzpicture}[scale=0.75,>=stealth,rotate=0]
  \fill[gray!40] (-4,-1) rectangle (0,1);
  \fill[pattern,pattern = north east lines] (-4,-1) rectangle (0,1)
  node[black,midway,fill=white]{$\epsilon_r$};
  \draw[thick] (0,1) -- (0,2);
  \draw[thick] (0,-1) -- (0,-2);
  \draw[ultra thick] (-4,1)--(4,1) node[midway,above
  left]{$A$};
  \draw[ultra thick] (-4,-1) -- (4,-1);
  \draw[<->] (3,1)--(3,-1) node[midway,fill=white]{$d$};
  %\draw[<->] (-2,0)--(-2,1) node[midway,right]{$d/2$};
  \begin{scope}[shift={(9,0)},scale=0.75/2]
    \node at (-9,0){$\Longleftrightarrow$};
    \fill[gray!40] (-5,-1) rectangle (-1,1);
    \fill[pattern,pattern = north east lines](-5,-1)rectangle(-1,1);
    \draw[thick] (0,3) -- (0,2);
    \draw[thick] (-3,1) |- (0,2) -| (3,1);
    \draw[ultra thick] (-5,1) node[above left]{$C_1$} -- (-1,1);
    \draw[ultra thick] (-5,-1)-- (-1,-1);
    \draw[ultra thick] (1,1)-- (5,1)node[above right]{$C_2$} ;
    \draw[ultra thick] (1,-1)-- (5,-1);
    \draw[thick] (0,-3) -- (0,-2);
    \draw[thick] (-3,-1) |- (0,-2) -| (3,-1);
    \fill (0,2)circle(0.15);
    \fill (0,-2)circle(0.15);
   \end{scope}
 \end{tikzpicture}
\end{document}