A transparent cylindrical rod of length l=50 ~cm , radius R=10 ~cm...

A transparent cylindrical rod of length $l=50 \mathrm{~cm}$, radius $R=10 \mathrm{~cm}$ and refractive index $\mu=\sqrt{3}$ lies onto a horizontal plane surface. A ray of light moving perpendicular to its length is incident on the rod horizontally at a height $h$ above the plane surface such that this ray emerges out of the rod at a height 10 cm above the plane surface. Therefore, $h$ is