Question

Find the refractive index of air w.r.t a certain material if the refractive index of that material to air is 0.4

Answer 1

Refractive index of water wrt air (water n air)= 4/3
Refractive index of glass wrt air (glass n air) = 3/2
Refractive index of glass wrt water ( glass n water) = (glass n air)× (air n water) = (glass n air)× (1/water n air) = 4/3 × 2/3 = 8/9.