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 magnification produced by the lens.

Given: The image distance, v = - 10 cm The focal length, f = - 15 cm From the lens formula, 1 f = 1 v - 1 u ⇒ 1 - 15 = 1 - 10 - 1 u ⇒ 1 u = - 1 30 ⇒ u = - 30 cm The object should be placed at 30 cm from the concave lens. The magnification, m = v u = - 10 - 30 = + 0 . 33 The magnification produced by the lens is + 0 . 33 .

E M B I B E

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 12

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10th CBSE

IMPORTANT

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Which type of lens is: (a) a converging lens, and which is (b) a diverging lens? Explain your answer with diagrams.

Important Questions on Refraction of Light

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10th CBSE

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Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 13

With the help of a diagram, explain why the image of an object viewed through a concave lens appears smaller and closer than the object.

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10th CBSE

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Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 14

How would a pencil look like if you saw it through (a) a concave lens and (b) a convex lens? (Assume the pencil is close to the lens). Is the image real or virtual?

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10th CBSE

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Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Long Answer Type Questions>Q 15

An object is placed