The refractive index of water with respect to air is $\frac{4}{3}$. The refractive index of air with respect to water will be:

The following table gives the refractive indices of a few media:

Use this table to give an example of a medium pair so that light speeds up when it goes from one of these medium to another.

The following table gives the refractive indices of a few media:

Use this table to give an example of:

A medium pair so that light slows down when it goes from one of these medium to another.

Refractive indices of four media $A, B, C$ and $D$ are given below:

In which of these four media is the speed of light (i) maximum, and (ii) minimum?

Name the lens which can concentrate sun's rays to a point and burn a hole in a piece of paper.

(Choose from: Convex lens, Concave lens)

Name the point inside a lens through which the light passes undeviated.