CBSE Class 10 Science 2019 · Paper 31/2/3 · Question 16(b)

Light - Reflection and Refraction 5 marks Medium

An object 6 cm in size is placed at 50 cm in front of a convex lens of focal length 30 cm. At what distance from the lens should a screen be placed in order to obtain a sharp image of the object ? Find the nature and size of the image. Also draw labelled ray diagram to show the image formation in this case.

Answer

The screen goes 75 cm from the lens, opposite the object; the image is real, inverted, enlarged and 9 cm tall ( $m = - 1.5$ ).

The screen should be placed

75

cm from the lens, on the side opposite to the object (

v = + 75

cm). Nature: real and inverted (and enlarged). Size:

m = \frac{v}{u} = \frac{75}{- 50} = - 1.5

, so

h^{'} = - 1.5 \times 6 = - 9

cm: the image is

9

cm tall. The labelled ray diagram shows the image formed beyond

2 F_{2}

and caught on the screen.

🔒 Step-by-step solution

From the board paper

CBSE Class 10 Science 2019 · Paper 31/2/3, Question 16(b) — all 27 questions with answers →

CBSE Class 10 Science 2019 · Paper 31/2/3 · Question 16(b)

Answer

From the board paper

More questions from Light - Reflection and Refraction