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>Very Short Answer Type Questions>Q 18

EASY

10th CBSE

IMPORTANT

Earn 100

Why does a ray of light bend when it travels from one medium to another?

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>Very Short Answer Type Questions>Q 19

Light travelling along a normal is _____ (completely/ partially/ not) refracted.

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Very Short Answer Type Questions>Q 19

Light bends when it passes from water into air. The phenomenon is known as _____ (reflection/refraction) of light.

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Very Short Answer Type Questions>Q 20

What is meant by 'refraction of light'? Draw a labelled ray diagram to show the refraction of light.

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 21

A ray of light travelling in air is incident on a rectangular glass block and emerges out into the air from the opposite face. Draw a labelled ray diagram to show the complete path of this ray of light. Mark the two points where the refraction of light takes place. What can you say about the final direction of ray of light?

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 22

Draw a labelled ray diagram to show how a ray of light is refracted when it passes:

from air into an optically denser medium.

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 22

Draw a labelled ray diagram to show how a ray of light is refracted when it passes:

from an optically denser medium into air.