As per recent understanding light consists of:

Choose the correct option:

Consider the optically denser lenses P, Q, R, and S drawn below. According to Cartesian sign convention which of these have positive focal length?

Two plane mirrors are inclined at angle ${40}^{\circ }$ between them. Number of images seen of a tiny object kept between them is_____.

A concave mirror of curvature $40 \mathrm{cm}$, used for shaving purpose produces an image of double size as that of the object. Object distance must be :

Choose the correct option.

Which of the following aberrations will NOT occur for spherical mirror ?

Consider the following phenomenon/ applications :

P) Mirage Q) Rainbow R) Optical fibre and S) Glittering of the diamond.

Total internal reflection is involved in_____?

Choose the correct option.

A student uses spectacles of number $-2$ for seeing distant objects. Commonly used lenses for his/her spectacles are_____.

Choose the correct option.

A spherical marble, of refractive index $1.5$ and curvature $1.5 \mathrm{cm}$, contains a tiny air bubble at its centre. Where will it appear when seen from outside?