Question

A student performs the experiment on tracing the path of a ray of light passing through a rectangular glass slab for different angles of incidence. He measures the angle of incidence ∠i, angle of refraction ∠r and angle of emergence ∠e for all his observations. He would find that in all cases:
(1) ∠i is more than ∠r but (nearly) equal to ∠e
(2) ∠i is less than ∠r but (nearly equal to ∠e
(3) ∠i s more than ∠e but (nearly) equal to ∠r
(4) ∠i is less than ∠e but (nearly) equal to ∠r

Answer 1

When a ray travels from a rarer medium to denser medium(Air to glass) it bends towards the normal, so the incidence angle is always more than the angle of refraction. But, when it travels from denser medium to rarer medium(Glass to air) then it bends away from the normal and becomes parallel to the incident ray, so the angle of emergence is (nearly) equal to the angle of incidence.

Hence, the correct answer is option 1.