A ray of light starting from air passes through medium A of refractive index $1.50$, enters medium B of refractive index $1.33$ and, finally enters medium C of refractive index $2.42$. If this ray emerges out in air from C, then for which of the following pairs of media the bending of light is least?

For the diagram shown, according to the new Cartesian sign convention the magnification of the image formed will have the following specifications.

A ray of light is incident as shown. If A, B and C are three transparent media, then which among the following options is true for the given diagram?

If a lens can converge the sun rays at a point $20 \mathrm{cm}$ away from its optical centre, the power of this lens is _____.

The radius of curvature of a converging mirror is $30 \mathrm{cm}$. At what distance from the mirror should an object be placed so as to obtain a virtual image?

A converging lens forms a three times magnified image of an object, which can be taken on a screen. If the focal length of the lens is $30 \mathrm{cm}$, then the distance of the object from the lens is _____.

Which of the following statements is not true in reference to the diagram shown above?

In the diagram shown above $n_1, n_2 \mathrm{and} n_3$ are refractive indices of the media $1,2 \mathrm{and} 3$ respectively. Which one of the following is true in this case?

The refractive index of medium A is $1.5$ and that of medium B is $1.33$. If the speed of light in air is  $3\times {10}^8 \mathrm{m}/\mathrm{s}$, what is the speed of light in medium A and B respectively?