\documentclass{article}

\usepackage{pgfplots}
\pgfplotsset{compat=1.11}

\begin{document}

\begin{tikzpicture}
	\begin{axis}[
		axis x line=middle,
		axis y line=center,
		axis equal,
		disabledatascaling,
		xmin=-0.5,xmax=10,
		ymin=-0.5,ymax=11,
		]
		\draw (axis cs:10,0) arc[radius=2, start angle=0, delta angle=180];
	\end{axis}
\end{tikzpicture}
\end{document}
