Question

The apparent depth of a vessel full of water is due to the of light.

• A. diffraction
• B. refraction
• C. dispersion
• D. diffusion

Answer 1

The correct option is B refraction

Light rays bend away from the normal when travelling from a denser medium to a rarer medium. While travelling from a rarer medium to a denser medium, they bend toward the normal.
In a vessel full of water, light rays coming from the bottom of the vessel bend away from the normal at the water-air interface, as water is optically denser than air. When these rays enter our eyes, we perceive an apparent shift in the position of the bottom of the vessel. This happens due to refraction of light. As a result, the vessel appears shallower than it actually is.