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

Reflection of Light Exe-7C Long Answer Concise Physics ICSE Class-9 Selina Publishers. There is the solutions of Long Answer 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 Long Answer Type

Concise Physics ICSE Class-9 Selina Publishers

 Board ICSE Class 9 Subject Physics Writer / Publication Concise Selina Publishers Chapter-7 Reflection of Light Exe-7C Spherical Mirrors Topics Solution of Exe-7(C) Long Answer Type Academic Session 2024-2025

### Exercise- 7C Spherical Mirrors

page -189

Ans- (i)

(ii)

##### Q2- Explain the meaning of the terms focus and focal length in case of a convex mirror, with the help of suitable ray diagram.

Ans- Focus of a convex mirror: The focus of a convex mirror is a point on the principal axis from which, the light rays incident parallel to principal axis, appear to come, after reflection from the mirror. Focal length of a convex mirror: The distance of the focus from the pole of the convex mirror is called its focal length.

##### (ii) In each case (a) and (b), draw reflected rays for the given incident rays and mark focus by the symbol F.

Ans (i) Figure (a) has convex mirror. and in Figure (b) has concave mirror.

(ii) (a)

(b)

Ans-

Ans-

##### Q6- State the two convenient rays that are chosen to construct the image by a spherical mirror for a given object? Explain your answer with the help of suitable ray diagrams.

Ans- Two convenient rays that are chosen to construct the image by a spherical mirror for a given object:

1 ) A ray passing through the centre of curvature: A ray of light passing through the centre of curvature of a concave mirror or a ray directed in the direction of centre of curvature of a convex mirror is reflected back along the same path after reflection.

2. A ray parallel to the principal axis: A ray of light parallel to the principal axis, after reflection pass through the principal focus in case of a concave mirror or appears to diverge from it in case of convex mirror.

Ans-

Ans-

##### Q9- The diagram below in Fig.7.54, shows a convex mirror. C is its centre of curvature and F is its focus. (i) Draw two rays from A and hence locate the position of image of object OA. Label the image IB. (ii) State three characteristics of the image.

Ans- The ray diagram shows two light rays from A. The image of the object OA is formed between the focus and the pole on the other side of the mirror.

The image so formed is erect, virtual and diminished.

Q10- Draw  a ray diagram to show the formation of image by a concave mirror for an object placed between its pole and focus. State three characteristics of the image.

Ans- Ray diagram showing the formation of an image by a concave mirror for an object placed between its pole and focus:

When the object is placed between focus F and pole P, the image is formed behind the mirror.

The image so formed is virtual, upright and magnified.

##### Q11 Draw a ray diagram to show the formation of image by a concave mirror for the object beyond its centre of curvature. State three characteristics of the image.

Ans- Ray diagram showing the formation of an image by a concave mirror for the object beyond its centre of curvature:

When the object is placed beyond the centre of curvature C, the image is formed between focus F and centre of curvature C. The image so formed is real, inverted and diminished

##### Q12- Draw a ray diagram to show the formation of image of an object kept in front of a convex mirror. State three characteristics of the image.

Ans-

The image formed is virtual, erect and diminished

##### Q13- Discuss the position and nature of image formed by a concave mirror when an object is moved from infinity towards the pole of mirror.

Ans- When  an object is moved from infinity towards the pole of mirror, the image formed moves away from the mirror. The image formed is real and inverted.

##### Q14- Discuss the position and nature of image formed by a convex mirror when an object is moved from infinity towards the pole of mirror.

Ans- In a convex mirror, the image formed is always virtual, upright and diminished. It is always situated between its pole and focus, irrespective of the distance of object in front of the mirror.

##### Q15- Why does a driver use a convex mirror instead of a plane mirror as a rear view mirror? Illustrate your answer with the help of a ray diagram.

Ans- A convex mirror diverges the incident beam and always forms a virtual, small and erect image between its pole and focus. Thus, a driver can see all the traffic approaching from behind. This fact enables the driver to use it as a rear view in vehicles to see all the traffic
approaching from behind.

—  end of Reflection of Light Exe-7C Long Answer Concise Physics ICSE Class-9 Selina Publishers Solutions :—

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