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 .

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Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Long Answer Type Questions>Q 30

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10th CBSE

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State two factors on which the lateral displacement of the emergent ray depends.

Important Questions on Refraction of Light

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Long Answer Type Questions>Q 31

Explain with the help of a labelled ray diagram, why a pencil partly immersed in water appears to be bent at the water surface. State whether the bending of pencil will increase if water is replaced by another liquid which is optically more denser than water. Give reason for your answer.