Question

A concave lens has focal length 15 cm. At what distance should the object from
the lens be placed so that it forms an image at 10 cm from the lens? Also find the
mgnification produced by the lens.
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Answer 1

We should keep the object at 7.5 cm from mirror .

And magnification produced is :

M = v ÷ u

= 15 ÷ 7.5

= 2

Hence Magnification is 2