Question

a transparent medium A floats on another transparent medium B. when a ray of light travels obliquely from A to B, the reflected ray bends away from the normal. Which of the 2 media A and B is optically denser and why?

Answer 1

The refracted ray bends away from the normal as it goes from medium A to medium B.This means that the ray is going from a denser medium to a rarer medium.
Therefore medium A is optically denser than B.
It is so because a ray of light bends towards the normal when it goes from a rarer medium to a denser and bends away from normal when it goes from a denser to a rarer medium.