%kernel.tikz
\begin{tikzpicture}[scale=2]
  \node[left] (O) at (0,0) {$O$};
  %Draw the Circle around it all
  \draw[semithick] (0,0) circle (1);
  \draw[dotted,red] (0,0) circle (1.5);
  \draw[dotted,blue] (0,0) circle (0.5);
  %Draw grid
  \draw[->] (-1.6,0) -- (1.6,0);
  \draw[->] (0,-1.6) -- (0,1.6);


  \node[below] (O) at (3,0) {$O$};
  %Draw the Circle around it all
  \draw (4,-0.1) -- (4,0.1);
  \draw[dotted,red] (4.5,-0.1) -- (4.5,0.1);
  \draw[dotted,blue] (3.5,-0.1) -- (3.5,0.1);
  %Draw grid
  \draw[->] (2.75,0) -- (5,0);
\end{tikzpicture}