(a) Which one of the two media is denser w.r.t. other medium? Justify your answer (based on a ray entering from medium A to B).

(b) If the speed of light in medium A is $v_a$ and in medium B is $v_b$, what is the refractive index of B with respect to A.

OR

(a) A ray of light starting from diamond is incident on the interface separating diamond and water. Draw a labelled ray diagram to show the refraction of light in this case.

(b) Absolute refractive indices of diamond and water are 2.42 and 1.33 respectively. Find the value of refractive index of water w.r.t. diamond.

Hint

The refractive index of a medium is defined as the ratio of the speed of light in vacuum to the speed of light in the medium.

Quick oral answer

The refractive index of a medium is a measure of how much it bends light. A higher refractive index indicates that the medium bends light more strongly. In this case, the refractive index of medium B with respect to medium A is given by n_BA = v_A / v_B. This means that if the speed of light in medium A is v_A and the speed of light in medium B is v_B, then the refractive index of medium B with respect to medium A is v_A / v_B.