Question

why does coin appear to be raised in water ?​

Answer 1

Answer:

This bending of light, called refraction, causes the apparent position of the coin to change to a shallower position1 (see diagram). The light bends when it passes from water to air on top of the water. It does the same thing when it passes through the glass, making the coin appear to be closer to you.

Answer 2

Answer:

The coin appears to be raised when viewed in water because as light travels from water to air(denser to rarer medium), it faces refraction and due to which its path bends. Thus, this bending of light makes us think that the apparent position of coin is above the normal position.