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 28

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10th CBSE

IMPORTANT

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Explain why, a stick half immersed in water appears to be bent at the surface. Draw a labelled diagram to illustrate your answer.

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 29

Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface. (Choose from reflection of light or 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>Long Answer Type Questions>Q 30

With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab, the emergent ray is parallel to the incident ray.

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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 30

Show the lateral displacement of the ray on the diagram of light ray obliquely falling on a glass slab.

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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 30

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

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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.

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Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Multiple Choice Questions (MCQs)>Q 33

A ray of light passes from glass into air. The angle of refraction will be:

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10th CBSE

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Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Multiple Choice Questions (MCQs)>Q 36

When a ray of light travelling in glass enters into water obliquely:

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10th CBSE