Explanation :
A coin placed at the bottom of a beaker containing water appears raised due to the refraction of light.
The bending of light when it moves from one medium to another is called as the refraction of light.
When the ray of light travels form denser to rarer medium it will bends away from the normal. In this case, water is a denser medium while air is a rarer medium. So, the coin appears to be raised and this is the apparent position of the coin.
