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.

With the help of a labeled diagram, explain why a tank full of water appears less deep than it actually is.

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

Show the lateral displacement of the ray on the diagram.

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