(a) With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is. (b) Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.
a) If we look into a tank of water, it appears to be less deep than it really is. This is due to the refraction of light which takes place when light rays pass from the tank of water into air. When we look into the tank, we do not see the actual bottom of the tank, we see a virtual image of the bottom of the pool which is formed by the refraction of light coming from the water into the air.
(b) Reflection of Light.