What must be the index of refraction of the liquid such that the direction of the light entering the liquid is not changed?

A ray of light is travelling in glass and strikes a glass/liquid interface. The angle of incidence is 51.0°, and the index of refraction of glass is n = 1.50.

1 Answer
A08
Apr 20, 2016

The refractive index of liquid must be #=1.50#

Explanation:

If a ray of light is traveling from glass to liquid, we know that

#sin\theta_l = \frac{n_g}{n_l}\sin\theta_g# ......(1)

where #theta_l and theta_g# are angel of refraction and angle of incidence and #n_l and n_g# are respective refractive indices.

It is required that the direction of light entering liquid must not change. This implies that #theta_l = theta_g#. If we insert this equality in the expression (1), we obtain

#n_l = n_g=1.50#
This is independent of angle of incidence.

Related questions
See all questions in Refractions
Impact of this question
3335 views around the world
You can reuse this answer
Creative Commons License