Reflection of Light Exe-7A Short Answer Concise Physics ICSE Class-9 Selina Publishers

Reflection of Light Exe-7A Short Answer Concise Physics ICSE Class-9 Selina Publishers. There is the solutions of Short 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-7A Short Answer Concise Physics ICSE Class-9 Selina Publishers

Reflection of Light Exe-7A Short 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-7A Laws of Reflection
Topics Solution of Exe-7(A) Short Answer Type
Academic Session 2024-2025


Exercise- 7A Laws of Reflection

page -170

Short Answer :

Q1- Explain the following term :

(a) Plane mirror  (b) Incident ray  (c) Reflected ray  (d)  Angle of incidence  and (e) Angle of reflection.  Draw diagram/diagrams to show them.

Ans (a) Plane mirror:

Plane mirror is a highly polished and smooth reflecting surface made from a clear plane glass sheet, usually thin and silvered with suitable reflecting abrasive (for example, mercury) on one side. Once this pasting is done, then the glass becomes opaque but due to the reflecting property of the abrasive, the plane glass sheet becomes a plane glass reflector or a plane glass mirror.

Plane mirror

Ans (b) incident ray.

The light ray striking a reflecting surface is called the incident ray.

Ans (c) reflected ray.

The light  ray obtained after reflection from the surface, in the same medium in which the incident ray is travelling, is called the reflected ray.

Ans (d)  Angle of incidence  

The angle which the incident ray makes with the normal at the point of incidence is called the angle of incidence. It is denoted by the letter “i”.

Ans (e) Angle of reflection.

The angle which the reflected ray makes with the normal at the point of incidence is called the angle of reflection. It is denoted by the letter r.

Q2- Differentiate between the reflection of light from a plane mirror and that from a plane wall.

Ans- Plane mirrors provide a specular reflection, forming a virtual image obeying the law of reflection, whereas plane walls undergo diffuse reflection with no well-defined image formation.

Q3- State the two laws of reflection of light.

Ans- Law of reflection:

  1. The angle of incidence is equal to the angle of reflection.
  2. The incident ray, the reflected ray and the normal at the point of incidence, lie in the same plane
Q4- Draw a diagram to show the reflection of a ray of light using a plane mirror. In the diagram, label the incident ray, the reflected ray, the normal, the angle of incidence and the angle of reflection.

Ans-

 Draw a diagram to show the reflection of a ray of light using a plane mirror. In the diagram, label the incident ray, the reflected ray, the normal, the angle of incidence and the angle of reflection.

Q5 (a) Write three characteristics of the image formed by a plane mirror? (b) How is the position of an image related to the position of the object?

Ans (a) Three characteristics of image formed by plane mirror:

(i) Image formed in erect (upright)

(ii) Image formed is virtual

(iii) Image formed is of the same size as the object.

Ans (b) The image is situated at the same perpendicular distance behind the mirror as the object in front of it.

Q6- Differentiate between a real and a virtual image.

Ans- Difference between a real and a virtual image

Real Image Virtual image
1. A real image is formed due to actual intersection of the reflected rays. 1. A virtual image is formed when the reflected rays meet if they are produced backwards.
2. A real image can be obtained on a screen. 2. A virtual image cannot be obtained on a screen.
3. A real image is inverted with respect to the object. 3. A virtual image is erect with respect to the object.
Q7- What is meant by lateral inversion of an image in a plane mirror? Explain it with the help of a ray diagram.

Ans- The interchange of the left and right sides in the image of an object in a plane mirror is called lateral inversion.
Q7- What is meant by lateral inversion of an image in a plane mirror? Explain it with the help of a ray diagram.

Figure above shows the image formation of a letter P in a plane mirror. The letter P appears in the plane mirror as P’ .

Q8- The letters on the front of an ambulance are written laterally inverted like  . Give reason.

Ans- The letters  on the front of a ambulance are written laterally inverted, so that the driver of the vehicle moving ahead of the ambulance reads these words laterally inverted as AMBULANCE, in his rear view mirror, and gives side to pass the ambulance first.

—  end of Reflection of Light Exe-7A Short Answer Concise Physics ICSE Class-9 Selina Publishers :

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