Question

A coin is placed in an empty vessel and is out of the line of sight of a person standing at a distance. When water is poured into this vessel, the coin becomes visible. How will you explain this?

Answer 1

Explanation -

1. When water is poured then it is due to refraction of light the coin becomes visible.
2. When the light rays travel from the water medium (denser) to the air medium (rarer) it bends away from the normal due to the refraction.
3. Therefore, an image of the coin is formed at a smaller depth causing it to be visible (as shown in the figure).