Concept:When light moves from a less dense medium (air) into a denser medium (water), it slows down and bends toward the normal.
Explanation:The ray makes an angle of
30∘ with the normal in air.
This angle is the angle of incidence:
i=30∘.
On entering water, which is denser than air, the refracted ray bends toward the normal.
Bending toward the normal means the angle of refraction is smaller than the angle of incidence.
Therefore, in water, the ray makes an angle less than
30∘ from the normal.
Answer:D. make an angle less than
30∘ from the normal in water.