Consider a tank made of glass(refractive index 1.5) with a thick bottom. It is filled with a liquid of refractive index μ. A student finds that,…

Consider a tank made of glass(refractive index $\displaystyle 1.5$) with a thick bottom. It is filled with a liquid of refractive index $\displaystyle \mu$. A student finds that, irrespective of what the incident angle $\displaystyle i$ (see figure) is for a beam of light entering the liquid, the light reflected from the liquid glass interface is never completely polarized. For this to happen, the minimum value of $\displaystyle \mu$ is :