S K Sharma Solutions for Chapter: Light Reflection and Refraction - Natural Phenomena, Exercise 1: UNSOLVED NUMERICALS FOR PRACTICE

The focal length of a convex mirror is $15 \mathrm{cm}$. Find its radius of curvature.

An object $4 \mathrm{cm}$ tall is placed on the principal axis of a concave mirror of focal length $20 \mathrm{cm}$ at a distance of $30 \mathrm{cm}$ from it. Find the position, nature and size of the image.

A concave mirror produces a real image of size $3$ times that of the object at a distance of $30 \mathrm{cm}$ from the pole of the mirror. Find the position of the object.

How far should an object be from the pole of a concave mirror of the focal length of $20 \mathrm{cm}$ to form a real image whose size is $\frac{1}{5}\mathrm{th}$ of the size of the object?   

A $3 \mathrm{cm}$ tall object is placed $18 \mathrm{cm}$ in front of a concave mirror of the focal length of $12 \mathrm{cm}$. At what distance from a mirror should a screen be placed to see a sharp image of the object on the screen. Also, calculate the height of the image formed. 

A concave mirror produces three times magnified image on a screen if the object is placed $20 \mathrm{cm}$ in front of the mirror, how far is the screen from the object?