Formation of the image When the object is placed between infinity and optical centre of the concave lens:
When an object AB is placed between infinity and optical centre of a concave lens, a ray of light AO which is parallel to the principal axis diverges along the direction OX after refraction and appears to come from the principal focus F along the direction OF. While the other ray of light AC goes straight through the optical centre C of the concave lens without any deviation along the direction CY. As it is clear from the figure (given below) that both the refracted rays i.e. OX and CY are diverging in nature, so these rays appear to intersect each other at point A’ on the left side of the lens on producing back. Hence, the image A’B’ formed in this case is a virtual image which is formed at the same side of the lens, between the optical centre and focus. Also the image formed is diminished and erect. Image: Formation of the image When the object is placed between infinity and optical centre of the concave lens

Image formed from the concave lens

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Differentiate between convex and concave lens.