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>Questions Based on High Order Thinking Skills (HOTS)>Q 50

EASY

10th CBSE

IMPORTANT

Earn 100

Draw a diagram to show how a converging lens focuses parallel rays of light.

Important Questions on Refraction of Light

MEDIUM

10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Questions Based on High Order Thinking Skills (HOTS)>Q 50

How would you alter the diagram of a converging lens focusing parallel rays of light to show how it can produce a beam of parallel rays of light?

EASY

10th CBSE

IMPORTANT

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

Write the formula for a lens connecting image distance

(v)

, object distance

(u)

and the focal length

(f)

. How does the lens formula differ from the mirror formula?

EASY

10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Very Short Answer Type Questions>Q 2

Write down the magnification formula for a lens in terms of object distance and image distance. How does this magnification formula for a lens differ from the corresponding formula for a mirror?

MEDIUM

10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Very Short Answer Type Questions>Q 3

What is the nature of the image formed by a convex lens if the magnification produced by the lens is