A linear potentiometer $(0-10 \mathrm{k} \Omega)$ is used to measure the water level as shown in the figure. The resistance between $\mathrm{A}$ and $\mathrm{C}$ varies linearly from 0 to $10 \mathrm{k} \Omega$ for a change in water level from 0 to $20 \mathrm{~cm}$. The sensor is excited using a DC voltage source, $\mathrm{V}_{\mathrm{S}}=10 \mathrm{~V}$ with an internal resistance, $\mathrm{RS}_{\mathrm{S}}=200 \Omega$. If $\mathrm{V}_{\text {out }}=5 \mathrm{~V}$, the water level is $\mathrm{cm}$ (rounded off to one decimal place).