If the absolute refractive indices of water, benzene, and sapphire are $1.33$, $1.50$, and $1.77$ respectively, then which medium has the maximum relative refractive index?

What is the nature of the image formed by an object placed at a distance of $10 \text{ cm}$ in front of a concave mirror with a focal length of $20 \text{ cm}$?

Define the term reflection.

$A$ full-length image of a distant tall building can definitely be seen by using:

$(a)$ $A$ ray of light falls normally on a face of a glass slab. What are the values of angle of incidence and angle of refraction of this ray?
$(b)$ Light enters from air to a medium $X$. Its speed in medium $X$ becomes $1.5 \times 10^{8} \ m \ s^{-1}$. Speed of light in air is $3 \times 10^{8} \ m \ s^{-1}$. Find the refractive index of medium $X$.

When a plane mirror is rotated through a certain angle,the reflected ray turns through twice as much and the size of the image