Question

A hunter desires to shoot a fish whose image could be seen through the clear water. His aim should be
A. Above the apparent image of the fish
B. Below the apparent image of the fish
C. In the line of sight of fish
D. Parallel to the surface of the water

Answer 1

Hint: According to the law of refraction, when light travels from water (denser medium) to air (rarer medium), it bends away from the normal. Hence, the image of the fish as seen to the hunter is at a greater height than the original position of the fish.

Complete step by step answer:
The hunter sees the fish when the light rays from the fish reach the eyes of the hunter. i.e., the light rays are travelling from water (denser medium) to the air (rarer medium). When the light rays from the fish reach the boundary between water and air, according to the law of refraction, light rays bend. Since light rays are travelling from a denser medium to a rarer medium it bends away from the normal. The ray diagram of the path of light is shown in the below figure. Here, normal is drawn perpendicular to the boundary between water and air.

Therefore, the apparent image of the fish appears above the actual position of fish. To correctly shoot the fish hunter needs to aim below the apparent image of the fish.

The correct answer is option (B).

Note: In these types of problems direction of light is very important. If the light is travelling from rarer to denser media, it bends towards the normal. If the light is travelling from denser to rarer media, it bends away from the normal.