Question

What would be the observation of a student who perform the experiment to trace the path of a ray of light towards the glass slab whose two opposites faces are not parallel to each other

Answer 1

The student will see that the ray of light will bend towards the normal while travelling from air to glass and then away from normal while travelling from glass to air & The angle of emergence will equal to the angle of incidence.

Answer 2

faces being parallel or not parallel does not matter because refraction of light occurs due to difference in optical densities of two media..

light travelling from air to glass will be normal and then it will bend away from normal while travelling from glass to air.

∠i = ∠e (angle of incidence = angle of emergence)

hope it helps =)