Question

Derive lens formula for a concave lens.

Answer 1

Let AB represent an object placed at right angles to the principal axis at a distance greater than the focal length f of the convex lens. The image A1B1 is formed between O and F1 on the same side as the object is kept and the image is erect and virtual.



lens formula


OF1 = Focal length = f

OA = Object distance = u

OA1 = Image distance = v











But from the ray diagram we see that OC = AB





From equation (1) and equation (2), we get







Dividing throughout by uvf





Answered by Ankit K | 16th Mar, 2019, 08:02: AM
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Answer 2

Explanation:

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