The diagram below shows a lens as a combination of a glass block and two prisms. Name the lens formed by the combination.

We can consider a lens as being made up of a rectangular block at the centre and one prism on either side of it. The lens formed by the above combination is a convex lens. This lens in its upper part has a prism with its base downwards and in its lower part has a prism with its base upwards.

The diagram below shows a lens as a combination of a glass block and two prisms. Name the lens formed by the combination.

We can consider a lens as being made up of a rectangular block at the centre and one prism on either side of it. The lens formed by the above combination is a concave lens. This lens in its upper part has a prism with its base upwards and in its lower part has a prism with its base downwards.

Study the diagram below. Complete the diagram to form the image of the object AB.

A diverging lens is a concave lens. The refraction of light rays as they pass through the lens determines how well the lens works. When light rays enter a concave lens, they diverge, causing the lens to behave like a diverging lens. Concave lenses create only virtual images.

Study the diagram given below. State the three characteristics of the image.

The convex lens is comparably thick in the middle and narrow at the bottom and upper borders, and converges light rays that move parallel to its principal axis (i.e. converges incident rays towards the principal axis). The edges curve outward instead of bending within. The image is always virtual. The image is always erect. The image is always diminished in size.

Study the diagram given below. Name a device in which this action of lens is used.

This action of lens is used in a magnifying glass. Convex lenses converge parallel rays going in and, convex lenses diverge rays. A convex lens is useful as a magnifying glass as it will produce a virtual enlarged image if the object is brought within the focal length.