Question

The refractive index of glass is `3//2` and refractive index of water is `4//3`. What would be the refractive index of water with respect to glass ? Does light travel faster in glass than in water?

Answer 1

Refractive index of water w.r.t. glass
`.^(g)n_(w) = ("refractive index of water")/("refractive index of glass") =(4//3)/(3//2) =(8)/(9)`
Now `.^(g)n_(w) = ("velocity of light in glass")/("velocity of light in water") = 8/9`
Therefore, light travels slower in glass than in water.