NCERT Solutions Class 6 Science Chapter 11

NCERT Solutions for Class 6 Science Chapter 11

Chapter 11 of Class 6 science covers concepts like opacity, transparent objects, concepts of reflection, formation of image by a pinhole camera, translucent objects, the formation of shadows, mirrors and their uses. As students are introduced to some new concepts in this chapter, they must attempt all the practise questions given at the end of the chapter in the NCERT book.

To help students solve the questions accurately, Extramarks provides NCERT Solutions for Class 6 Science Chapter 11. The answers are written in simple language and explained through relevant examples or images, wherever required.

NCERT Solutions for Class 6 Science Chapter 11- Light, Shadows and Reflections

Access NCERT Solutions for Science Class 6 Chapter 11- Light, Shadows and Reflections

NCERT Solutions for Class 6 Science– Free Download 

Chapter 11 – Light, Shadow & Reflection

Light is a form of energy that helps us in seeing different objects around us. When light hits an object, some of its illuminations get reflected. It is because of this reflection that we can see things around us. In the dark, we cannot see any object because there isn’t any reflection and not because there isn’t enough light. Thus, the NCERT Class 6 Science Chapter 11 provided by us will give you a thorough insight into the chapter on light, shadow and reflection.

What are the Sources of Light?

The following are the two sources of light:

  • Luminous- A natural or artificial body that emits light on its own. Sun, tube light, and bulb are a few examples.
  • Non-Luminous- A body that does not emit light on its own. Moon, mirrors etc are a few examples of non-luminous sources of light.

Note: If we hold a mirror in a dark room, we can't see objects through it. Thus, we only see things in the mirror because it reflects.

Transparent, Translucent and Opaque

  • Transparent: If a source of light passes through an object, such an object is called a transparent object. A few examples of transparent objects include glass, water etc.
  • Translucent: If a source of light partially passes through an object, such an object is called a translucent object. A few examples of translucent objects include frosted glass, butter paper etc.
  • Opaque: If a source of light is unable to pass through an object, the object is called an opaque object. Such an object completely blocks the path of light. A few examples of such an object include wood, Earth etc. 

Formation of Shadows

When an opaque object blocks a source of light, it leads to the formation of a shadow. The opposite side or darker side creates a shadow. The distance between a source of light and an opaque object determines the size of the formed shadow. Here, the angle of light also plays an important role. 

Various Sizes of Shadows

  • As the source of light comes closer to an opaque object, the size of the shadow tends to increase. On the opposite side, the size reduces as the source of light moves farther away from the object.
  • When the shadow falls on a screen, only then the shadow created by an opaque object can be seen. This includes anything from the ground and walls of a room to any surface that can act as a screen.
  • In some cases, the shadow formed can provide a lot of information about the object.
  • Shadows are always black and are not affected by the change in the colour of the opaque object.

Propagation of Light

Light travels in a straight line. This is known as the rectilinear propagation of light. The chapter discusses two important concepts - Beam of light and Ray of light.

  • A beam of light: It is a bunch of rays moving in a specific direction.
  • Ray of light: It is the path through which light travels in a specific direction.

Reflection of Surfaces

Light reflects when it bounces off a surface but the nature of such a reflection depends on the type of surface it reflects from. If a source of light falls on an irregular surface, parallel beams of light reflect in different directions on the bases of the angles on the surface. This process is called diffused reflection. 

If a source of light falls on a smooth surface, the parallel beams of light will reflect uniformly to a single direction as per the angle of the light. This is called image. 

Key Features of NCERT Solutions for Class 6 Science Chapter 11

At times, students are unable to answer the textbook questions, even after studying the chapter. This is where NCERT Solutions for Class 6 Science Chapter 11 can be helpful. Here are a few benefits of referring to these study materials:

  • Students can access the study materials on the website or app of Extramarks.
  • The solutions are prepared by subject matter experts who have years of experience in teaching and are well-versed with the latest guidelines of CBSE.
  • The answers are accurate and explained with the help of relevant examples.

Q.1 Rearrange the boxes given below to make a sentence that helps us understand opaque objects.

Ans- It would be “Opaque objects make shadows”.

Q.2 Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:

Air, water, a piece of rock, a sheet of aluminium, a mirror, a wooden board, a sheet of polythene, a CD, smoke, a sheet of plane glass, fog, a piece of red hot iron, an umbrella, a lighted fluorescent tube, a wall, a sheet of carbon paper, the flame of a gas burner, a sheet of cardboard, a lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, moon.

Ans-

Object

Transparent
/Translucent
/Opaque

Luminous/Non-luminous

Air

Transparent

Non-luminous

Water

Transparent

Non-luminous

Piece of rock

Opaque

Non-luminous

Sheet of aluminum

Opaque

Non-luminous

Mirror

Opaque

Non-luminous

Wooden Board

Opaque

Non-luminous

Sheet of polythene

Translucent

Non-luminous

CD

Translucent

Non-luminous

Smoke

Translucent

Non-luminous

Sheet of plane glass

Translucent

Non-luminous

Fog

Translucent

Non-luminous

Piece of red hot iron

Opaque

Luminous

Umbrella

Opaque

Non-luminous

Lighted fluorescent tube

Opaque

Luminous

Wall

Opaque

Non-luminous

Sheet of carbon paper

Opaque

Non-luminous

Flame of a gas burner

Translucent

Luminous

Sheet of cardboard

Opaque

Non-luminous

Lighted torch

Opaque

Luminous

Sheet of cell phone

Translucent

Non-luminous

Wire mess

Translucent

Non-luminous

Kerosene stove

Opaque

Luminous

Sun

Opaque

Luminous

Firefly

Opaque

Luminous

Moon

Opaque

Non-luminous

Q.3 Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way?


Ans-

A cylinder kept in sunlight can form a circular shadow or a rectangular shadow. It can be obtained depending on its orientation related to the Sun. The cylinder forms a circular shadow when its top faces the Sun. When the side of the cylinder faces the Sun, then it forms rectangular shadow.

Q.4 In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror?

Ans-

In a completely dark room, there will be no light. The formation of an image depends upon the reflection of light. Therefore, no reflection of light takes place by the mirror placed in the dark room. Hence, no image will get formed by a mirror in a completely dark room.

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FAQs (Frequently Asked Questions)
1. How to prepare Chapter 11 of Class 6 Science for examination?

Science is one of the most important subjects for students that requires a lot of conceptual knowledge. By revising the chapters daily, you can have a firm grip on the key concepts. The NCERT Solutions by Extramarks are prepared by subject matter experts and will help students in preparing for their exams. The solutions will give students an idea of how to attempt a question in the right way to score higher marks in exams.

2. What is the difference between shadow and image?

An image is formed by the intersection of reflected rays while a shadow is formed when the light does not reach behind the object. When the reflected rays reach the eyes of the observer, they can see the image. However, in the case of a shadow, the light does not enter the eyes of the observer. While an image can be straight or inverted, providing us the information such as colour and structure, a shadow is not inverted and does not provide us the information of colour or structure.

3. Discuss the concept of shadow and reflection.

When light falls on an object, some amount of it is reflected. This reflected amount of light comes back to the human eyes and that is how we can see that particular object through which the light reflects. The sun is an excellent example of a luminous object that produces light. 

4. Which property of light is responsible for the formation of a shadow?

When there is a barrier in the way of light, the light usually bounces back. The reason for such a shielded place is a shadow because the light is unable to reach that place. We see the shadow as light is all over the object except its shielded area.

5. Discuss eclipse as per Chapter 11 of Class 6 Science. Explain its types.

Eclipse is the formation of shadows by celestial bodies on one another. It is of two types-

  • A solar eclipse is the one that occurs when the shadow of the moon falls on the earth when it comes in between the sun and the earth.
  • A lunar eclipse is the one that occurs when the shadow of the earth falls on the moon when it comes in between the sun and the moon.