[" Explain with the help of a diagram,why a pencil partly immersed in water appears to be "],[" bent at the water surface."]

Explain with diagram ,why a rod when partialy immersed in water appears to be bent.

Explain with the help of a diagram, why a rod immersed partially in a transparent liquid appears to be bent at the surface of the liquid.

A stick partially immersed obliquely under water appears to be bent.Explain,why.