# Reflection of Light Exe-7C Numericals Concise Physics ICSE Class-9 Selina Publishers

Reflection of Light Exe-7C Numericals Concise Physics ICSE Class-9 Selina Publishers. There is the solutions of Numerical type Questions of your latest textbook which is applicable in 2024-25 academic sessionVisit official Website CISCE for detail information about ICSE Board Class-9

## Reflection of Light Exe-7C Numericals

Concise Physics ICSE Class-9 Selina Publishers solutions

 Board ICSE Class 9 Subject Physics Writer / Publication Concise Selina Publishers Chapter-7 Reflection of Light Exe-7C Sphericals Mirrors Image Formation Topics Solution of Exe-7(C) Numericals Academic Session 2024-2025

### Spherical Mirrors Numerical Problems

Reflection of Light Exe-7C Numericals Concise Physics ICSE Class-9 Selina Publishers

page -189

##### Que -1: The radius of curvature of a convex mirror is 40 cm. Find its focal length.

Solution- Focal length = ½ (Radius of curvature)

Or, f = 402 = 20 cm.

##### Que-2: The  focal length of a concave mirror is 10 cm. Find its radius of curvature.

Solution- Radius of curvature = 2 × focal length

Or, R = 2f = 2 × 10 = 20 cm.

##### Que-3: An object of height 2 cm is placed at a distance of 20 cm in front of a concave mirror of a focal length of 12 cm. Find the position, size, and nature of the image.

Solution-

The image is 30 cm in front of the mirror, 3 cm high, real, inverted and magnified.

##### Que-4: An object is placed at 4 cm distance in front of a concave mirror of radius of curvature 24 cm. Find the position of image. Is the image magnified?

Solution-

The image is 6 cm behind the mirror.

Yes the image is magnified.

##### Que-5: At what distance from a concave mirror of focal length 25 cm should an object be placed so that the size of image is equal to the size of the object.

Solution- The size of the image is equal to the size of the object if the object is placed at the centre of curvature of a concave mirror.

Hence, the object should be placed at 50 cm.

##### Que-6: An object  5 cm high is placed at a distance 60 cm in front of a concave mirror of focal length 10 cm. Find the position and size of the image.

Solution-

The position of the object is 12 cm in front of the mirror.
Its size is 1 cm.

##### Que-7:  A point light source is kept in front of a convex mirror at a distance of 40 cm. The focal length of the mirror is 40 cm. Find the position of image.

Solution-

The image is behind the mirror at a distance 20 cm.

##### Que-8: When an object of height 1 cm is kept at a distance 4 cm from a concave mirror, its erect image of height 1.5 cm is formed at a distance 6 cm behind the mirror. Find the focal length of mirror

Solution-

A ray passing parallel to the principal axis passes through the focal point after reflection. Hence, the focal length is 12 cm.

##### Que-9: An object of length 4 cm is placed in front of a concave mirror at distance 30 cm. The focal length of mirror is 15 cm.
1. Where will the image form?
2. What will be the length of image.

Solution-

Solution-

##### Que-11: A concave mirror forms a virtual image of size twice that of the object placed at a distance 5 cm from it.

Find : (a) the focal length of the mirror (b) position of image

Solution-

Solution-

##### Que-13: The erect image formed by a concave mirror is of size double the size of object. How are u and v image?

Solution- Magnification is

##### Que-14:  The magnification for a mirror is -3. How are u and v related?

Solution- Magnification of a mirror is

—  end of Reflection of Light Exe-7C Numericals Concise Physics ICSE Class-9 Selina Publishers solutions  :—

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