Show the lateral displacement of the ray on the diagram.

Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.

With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab, the emergent ray is parallel to the incident ray.

State two factors on which the lateral displacement of the emergent ray depends.

Explain with the help of a labeled ray diagram, why a pencil partly immersed in water appears to be bent at the water surface. State whether the bending of pencil will increase or decrease if water is replaced by another liquid which is optically more dense than water. Give reason for your answer.