Question

When an object is kept in between the optical centre and focus in front of a convex lens, draw a ray-diagram of image formation.

Answer 1

Hint: Two spherical surfaces usually consist of an optical lens. The lens is called a biconvex lens or merely a convex lens because both surfaces are bent internally. These lenses will concentrate a beam of light from outside and focus on the other side. This is known as the focus, and the focus length of the convex lens is the distance from the centre of the lens to the focus. But if one of the surfaces is flat and the other is convex, in such a case, it will be known as a plano-convex lens.

Complete step-by-step answer:
If an object is placed between the optical centre and the focal point of a virtual convex lens, the image is erect and enlarged. The image formed for the concave lens is virtual, the image is erect and the image diminished.

A magnifying glass is another common example of the application of this type of lens. When an object is located a little longer than the lens' focal length in front of it, a magnified and upright object image is produced on the same face as the object. The first image is the human eye lens. And it helps one to see the through usage of lenses. Hypermetropia or long-sightedness is corrected.

Note: A simple form of lens can focus light in a frame, but the image is not high in quality. It is better to combine both types of lenses to correct distortions and aberrations. It is used in cameras because light is concentrated and a clear and tight picture produced. Most commonly they are used in composite devices, such as magnifiers, telescopes and camera lenses, of specific instruments.