A mark at the bottom of the liquid appears to rise by 0.2 m, If depth of the liquid is 2.0 m then refractive index of the liquid is__
$ Hera , n = { h \over h'} $ $ \therefore h' = 2.0 -0.2 = 1.8 $ $ \therefore {2 \over 1.5 } = { 20 \over 18} = 1.11 = n $