Exercise

The diameter of the reflecting surface of spherical mirror is

Find the image distance when an object is placed on the principal axis at a distance of $20 \mathrm{cm}$ in front of a concave mirror whose radius of curvature is $8 \mathrm{cm}$.

An object of $3 \mathrm{cm}$ height is placed at a distance of $10 \mathrm{cm}$ in front of a concave mirror of focal length $20 \mathrm{cm}$. The magnification produced by the mirror is

What is the unit of refractive index?

Draw a diagram to show what we mean by the angle of incidence and angle of refraction for a refracted ray of light.

The speed of light in a block of glass is found to be $1.90\times {10}^8 {\mathrm{ms}}^{-1}$. Calculate the refractive index of the glass. (The speed of light in a vacuum is $3\times {10}^8 {\mathrm{ms}}^{-1}$)

What do you mean by emergent ray?

Define angle of refraction.