Light in a vacuum is incident on a transparent glass slab. The angle of incidence is 40.6°. The slab is then immersed in a pool of liquid. When the angle of incidence for the light striking the slab is 11.7°, the angle of refraction for the light entering the slab is the same as when the slab was in a vacuum. What is the index of refraction of the liquid.
This is a good example of determination of refractive index using Snell's Law.