EXERCISES

One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object?

An object $5 \mathrm{cm}$ in length is held $25 \mathrm{cm}$ away from a converging lens of focal length $10 \mathrm{cm}$. Draw the ray diagram and find the position, size and the nature of the image formed.

A concave lens of focal length $15 \mathrm{cm}$ forms an image $10 \mathrm{cm}$ from the lens. How far is the object placed from the lens? Draw the ray diagram.

An object is placed at a distance of $10 \mathrm{cm}$ from a convex mirror of focal length $15 \mathrm{cm}$. Find the position and nature of the image.

The magnification produced by a plane mirror is $+1$. What does this mean? 

An object $5 \mathrm{cm}$ in length is placed at a distance of $20 \mathrm{cm}$ in front of a convex mirror of radius of curvature $30 \mathrm{cm}$. Find the position of the image, its nature, and size.

An object of size $7.0 \mathrm{cm}$ is placed at $27 \mathrm{cm}$ in front of a concave mirror of focal length $18 \mathrm{cm}$. At what distance from the mirror should a screen be placed so that a sharply focused image can be obtained? Find the size and nature of the image.

Find the focal length of a lens with power $-2.0$ diopter. What type of lens is this?