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 .

EASY

10th CBSE

IMPORTANT

Earn 100

Explain with the help of a diagram, why the concave lens is also called a diverging lens.

Important Questions on Refraction of Light

EASY

10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 18

Define the principal focus of a concave lens.

EASY

10th CBSE

IMPORTANT

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

Draw a ray diagram to show the formation of a real magnified image by a convex lens. (In your answer book sketch the position of object and image with respect to the principal focus of lens should be shown clearly).

EASY

10th CBSE

IMPORTANT

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

Describe with the help of a ray-diagram, the formation of image of a finite object placed in front of a convex lens between

f

and

2 f

. Give two characteristics of the image so formed.

EASY

10th CBSE

IMPORTANT

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

Describe with the help of a ray diagram the nature, size and position of the image formed when an object is placed in front of a convex lens between focus and optical centre. State three characteristics of the image formed.

EASY

10th CBSE

IMPORTANT

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

An object is placed at a distance equal to

2 f

in front of a convex lens. Draw a labelled ray diagram to show the formation of image. State two characteristics of the image formed.

EASY

10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 23

Describe with the help of a ray-diagram, the size, nature and position of the image formed by a convex lens when an object is placed beyond

2 f

in front of the lens.

EASY

10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 24

Describe with the help of a ray diagram the nature, size and position of the image formed when an object is placed at infinity (considerable distance) in front of a convex lens. State three characteristics of the image so formed.

EASY

10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 5 - Refraction of Light>Short Answer Type Questions>Q 25

What type of lens is shown in the diagram on the right? What will happen to the parallel rays of light? Show by completing the ray diagram.

Question Image

Explain with the help of a diagram, why the concave lens is also called a diverging lens.

Important Questions on Refraction of Light

Learn and Prepare for any exam you want !