### Theory:

Image formation in a convex lens
1. A convex lens is fixed on a stand for support and placed on the table.
2. A cardboard sheet of $${15\ cm} \times{10\ cm}$$ is taken, and a white sheet is pasted on it. This sheet will act as a screen.
3. A candle is lighted and placed at a certain distance from the convex lens.
4. The candle is placed on the other side of the lens, and its position is adjusted to obtain a sharp image of the flame on the screen.
5. Even the screen is also adjusted to get the image of the flame.

Inference
When the lens is placed at a large distance from the object, the image formed is real, inverted and smaller (or highly diminished) than the object.

When the lens is moved a little closer to the object, the image formed will be real, inverted and magnified on the screen.

If the convex lens is brought even closer to the object, the image will not be formed on the screen. But, it can be viewed on the mirror as a virtual, erect and highly magnified image.

Use of convex lenses
1. Convex lenses are used as magnifying glasses.

2. Convex lenses are used in cameras to focus and magnify the image.

3. It is also used in telescopes and binoculars to see distant objects clearly.

Binocular and telescope

4. In spectacles and contact lenses, they correct vision and helps to see the objects clearly.

Spectacles and a girl wearing a contact lens