Question

Explain with the help of a diagram why a pencil partly immersed in water appears to be bent at the water surface

Answer 1

a pencil partly immersed in water appears to be bent at the water surface due to refraction of light. an object placed in a denser medium when viewed from a rarer medium appears to be at a lesser distance than its real distance.

in the attachment:
Let AB be the pencil
Let AB' be the refracted image of AB
Let AC be the path of the ray without deflection .
since the ray is travelling to denser to rarer it bends away from the normal and thus the pencil seems to be raised to the viewer.
I hope that it was helpful!!☺