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NCERT Solutions for Class 8 Science Chapter 16 - Light

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Last updated date: 22nd Mar 2024
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MVSAT 2024

NCERT Solutions for Class 8 Science Chapter 16 Light - Free PDF Download

NCERT Solutions for Class 8 Physics Chapter 16 - Light PDF is now available to download for you on the official website of Vedantu. Download the comprehensive PDF of NCERT Solutions to review Class 8 Science Chapter 16 - Light and Class 9 Science crafted by seasoned educators with years of teaching experience, these solutions ensure a thorough understanding of the subject matter. They have a great experience and are experts in explaining the questions as well as giving the solutions and making you understand quickly and easily. Maths Students who are looking for better solutions ,They can download Class 8 Maths NCERT Solutions to help you to revise complete syllabus and score more marks in your examinations.


Class:

NCERT Solutions For Class 8

Subject:

Class 8 Science

Chapter Name:

Chapter 16 - Light

Content Type:

Text, Videos, Images and PDF Format

Academic Year:

2023-24

Medium:

English and Hindi

Available Materials:

Chapter Wise

Other Materials

  • Important Questions

  • Revision Notes


In case, you have queries, visit the official website of Vedantu and go through the questions and answers then get in touch with the experts or teachers and they will clear all of your doubts.

Access NCERT Solutions for Class 8 Science Chapter 16 – Light

  1. Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room? Explain.

Ans: In a dark room, one cannot see things in a room, but things outside the room will be visible.

The reason for this is that the object is only visible when light from the object reaches the eye. In a dark room, we cannot see objects because the rays of light do not reach our eyes whereas, in a lighted room, the rays of light reflected from the objects reach our eyes making them visible to us.


  1. Differentiate between regular and diffused reflection. Does diffused reflection mean the failure of the laws of reflection?

Ans: The difference between regular and diffused reflection is as follows:

Regular Reflection

Diffused Reflection

Regular Reflection takes place from a smooth and shiny surface.

Diffused Reflection takes place on a rough or irregular surface.

All rays are parallel after reflection.

The reflected rays are not parallel to each other.

Diffused reflection is not due to the failure of the laws of reflection. It is caused by irregularities in the reflecting surface.


  1. Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case.

a. Polished wooden table

Ans: A polished surface means the surface is very smooth, thus

regular reflection takes place.

b. Chalk powder

Ans: A diffused reflection takes place on a chalk powder because its surface is uneven.

c. Cardboard surface

Ans: The surface of cardboard that reflects light is not smooth, thus diffused reflection will take place from a cardboard surface.

d. Marble floor with water spread over it

Ans: The water spread over marble makes the surface very

Smooth which makes it act like a plane surface. Hence, regular reflection takes place.

e. Mirror

Ans: The surface of the mirror is very smooth and shiny. Therefore, regular reflection takes place.

f. Piece of paper

Ans: A piece of paper may look smooth, but it has many irregularities on its surface. Thus, diffused reflection takes place.


  1. State the laws of reflection.

Ans: Laws of reflection can be stated as follows:

  1. The angle of reflection and angle of incidence is always equal to each other.

  2. The incident ray, the normal at the point of incidence and the reflected ray all lie in the same plane.


  1. Describe an activity to show that the incident ray, the reflected ray and the normal at the point of incidence lie in the same plane.

Ans: To perform this experiment take a plane mirror and place it on a plane sheet of paper in a standing position with a block. Then draw an incidence line AB on this paper. Mark the points on the paper by carefully looking at the mirror. The line that goes after it appears on the screen. Draw a perpendicular on the mirror line and then remove the mirror. Join the points to make the reflected ray on the paper. You will observe that incident ray, reflected ray and normal will be in the same plane, i.e. on the sheet of paper. This verifies the law of reflection.


Law of Reflection


  1. Fill in the blanks in the following.

a. A person \[1\] m in front of a plane mirror seems to be ____ m away from his image.

Ans: A person \[1\] m in front of a plane mirror seems to be \[2\] m away from his image.

b. If you touch your ________ ear with your right hand in front of a plane mirror, it will be seen in the mirror that your right ear is touched with your _________.

Ans: If you touch your left ear with your right hand in front of a plane mirror, it will be seen in the mirror that your right ear is touched with your left hand.

c. The size of the pupil becomes ________ when you see in dim light.

Ans: The size of the pupil becomes large when you see it in dim light.

d. Night birds have _________ cones than rods in their eyes.

Ans: Night birds have lesser cones than rods in their eyes.


  1. The angle of incidence is equal to the angle of reflection.

a. Always

b. Sometimes

c. Under special conditions

d. Never

Ans: (a) Always

Since the first law of reflection states that the angle of incidence and

the angle of reflection is always equal to each other.


  1. The image formed by a plane mirror is

a. Virtual, behind the mirror and enlarged.

b. Virtual, behind the mirror and of the same size as the object.

c. Real at the surface of the mirror and enlarged.

d. Real, behind the mirror and of the same size as the object.

Ans: (b) Virtual, behind the mirror and of the same size as the object.

The image created by the plane mirror is built behind the mirror. This image cannot be created on screen, so it produces a virtual image of the size that of the object.


  1. Describe the construction of a kaleidoscope.

Ans: The Kaleidoscope is made up of three rectangular squares each about \[15\] cm long and \[4\] cm wide which are joined together to build a prism. They are arranged in a circular cardboard tube. Note that the tube is slightly longer than the screen straps. One end of the tube is closed with a cardboard disc with a hole in the middle. To make the disk last longer, a piece of transparent plastic paper is attached to the bottom of the cardboard disk. At the other end, a round plate of the glass plane is fixed touching the mirrors.


Kaleidoscope


  1. Draw a labelled sketch of the human eye.

Ans: 

Human Eye


  1. Gurmit wanted to perform Activity \[16.8\] using a laser torch. Her teacher advised her not to do so. Can you explain the basis of the teacher’s advice?

Ans: The intensity of the laser light is very high which is harmful to the eye and can cause a permanent defect in the eye. She can lose her eyesight also due to severe damage to the retina. Therefore, it is advisable not to look at a laser beam directly.


  1. Explain how you can take care of your eyes.

Ans: To protect our eyes, the following precautions should be taken:

i. Do not read in too little or too much light.

ii. Wash your eyes frequently with cold water.

iii. Do not read by bringing your book too close to your eyes or keeping it too far.

iv. Never rub your eyes.

v. If particles of dust go into our eyes, wash our eyes with clean water. If there is no improvement go to a doctor.


  1. What is the angle of incidence of a ray if the reflected ray is at an angle of \[{{90}^{\circ }}\] to the incident ray?

Ans: We know that angle of incidence is equal to the angle of reflection. Therefore, twice of incidence angle is equal to \[{{90}^{\circ }}\].

Thus, Angle of incidence \[i=\dfrac{{{90}^{\circ }}}{2}\] .

\[\Rightarrow i={{45}^{\circ }}\]


  1. How many images of a candle will be formed if it is placed between two parallel plane mirrors separated by \[40\] cm?

Ans: Since the mirrors are kept parallel to each other, and Infinite no of images will be formed due to multiple reflections between them.


  1. Two mirrors meet at right angles. A ray of light is incident on one at an angle of \[{{30}^{\circ }}\] as shown in Fig. \[16.19\]. Draw the reflected ray from the second mirror.


Ray of Light


Ans: From the first law of reflection, The angle of reflection and angle of incidence is always equal to each other.

The diagram of the reflected ray from the second mirror is as follows:


Ray of Light


  1. Boojho stands at \[A\] just on the side of a plane mirror as shown in Fig. \[16.20\]. Can he see himself in the mirror? Also, can he see the image of objects situated at \[P,Q,R\]?


Plane Mirror


Ans:  \[A\] cannot see his image as the length of the mirror is too short on his side. He can see the image of the objects at \[P\] and \[Q\] but cannot see the object at \[R\] as can be inferred from the ray diagram.


Plane Mirror


  1. Solve the below referring to the given diagram.


Plane Mirror


a. Find out the position of the image of an object situated at \[A\] in the plane mirror.

Ans: The image of \[A\] is formed behind the mirror at the same distance as that of \[A\] from the mirror.


Plane Mirror


b. Can Paheli at \[B\] see this image?

Ans: Yes, Paheli at \[B\] can see the image.

c. Can Boojho at \[C\] see this image?

Ans: Yes, Boojho at \[C\] can see the image.

d. When Paheli moves from \[B\] to \[C\], where does the image of \[A\] move?

Ans: The image of \[A\] is unaffected by the movement of \[B\] and \[C\]. Therefore, Paheli will be able to see the image of \[A\] while moving from \[B\] to \[C\].


NCERT Solutions for Class 8 Science Chapter 16 – Free PDF Download

If you are looking for the NCERT Solutions for Science Class 8 Chapter 16, then this is the perfect platform for you. The answers are prepared by the experts and are uploaded in PDF format on the official website of Vedantu.  It can help you to download the Light Class 8 solutions and find out the answers for the required questions easily.


NCERT Solutions for Science Class 8 Chapter 16

Introduction

The world is mostly known through the senses. In the NCERT Solutions for Class 8 Science Chapter 16, Why the sense of sight is one of the essential senses is explained. Through it, we see mountains, rivers, trees, plants, chairs, people and so many other things around us. We also see clouds, rainbows and birds flying in the sky. At night we see the moon and the stars. The words and sentences printed on this page. How is seeing made possible?

In the earlier chapters, you must have learnt about some natural phenomena. In this chapter, charging by rubbing is properly explained. The transfer of Charge is also discussed. How to deal with thunderstorms and about the Earthquake? In this chapter, what makes things visible is also explained. The Ch 16 Science Class 8 begins with the Laws of Reflection. NCERT Solutions for Class 8 Science Chapter 16 Light there will be a discussion about the Regular and Diffused Reflection. How does regular reflection form images? If reflected Light can be reflected again, what happens? The Kaleidoscope is also explained properly. You will learn about the colour of the Sun Light — it is white or coloured.

How Visually can Impaired Persons read and write in NCERT Class 8 Science Chapter 16? How can a night bird (owl) see very well in the night but not during the day? On the other hand, why dayLight birds (kite, eagle) can see well during the day but not in the night. What are the things that the owl has that allows more Light in its eye? The most popular resource for a visually challenged person is also explained here. What is the Braille System in the Light chapter Class 8? If you can see an object in a dark room, how is it possible? All of these things are explained here.

The activity that shows the incident ray, the reflected ray and the normal at the point of incidence stay in the same plane. The chapter explains about Image formed by a plane mirror. How can you take care of your eyes? How is the angle of incidence always equal to the angle of reflection? What happens if two plane mirrors are used in combination? What happens if two plane mirrors are used in combination? The idea of the number of images generated by mirrors placed at an angle to one another is utilized to make numerous beautiful patterns.

The process of making a kaleidoscope has been described in the Class 8 Science Chapter 16 solutions. What is there inside our eyes? Why do we see things only when Light coming from them enters our eyes? Why is the eye one of our most important sense organs? Why is it essential to understand its structure and to work? The chapter will discuss the dark, muscular structure of the eye and what a Pupil is. It explains about the cornea and the function of the optic nerve.


Recall

In NCERT Solutions Class 8 Science Chapter 16, you will recall what you were taught in your previous class about. You will be rekindled about some natural phenomena and if reflected Light can be reflected again. You will also recall the kaleidoscope and what happens if two plane mirrors are used in combination. Be relinked with the process of making a kaleidoscope, the braille system and with the most popular resources for a visually challenged person. In the NCERT Solutions for Class 8 Science Chapter Light, recall how to take care of your eyes and the colour of the sunLight. Recall the importance of the eye, the structure of an eye, and it’s working and why it is essential to know about it.


Exercise

The solutions of the Class 8 Science Chapter Light exercise are prepared by our experts, that helps you to understand the questions and answers easily.

Based on your understanding of what you have learnt until now, you will have to find out the solutions by explaining every minute detail. In order to find out the NCERT Solutions for Class 8 Science CH 16, you can access the PDF file to find the NCERT Solution of Class 8 Science Chapter 16 that is prepared by experts to learn more.


Key Features of NCERT Solutions for Class 8 Science Chapter 16

Students must go through these Class 8th Science Chapter 16 solutions so that they can fetch good marks in the exams. These NCERT Solutions for Class 8 Science Chapter 16 Light are prepared by our experts who have the right experience in this field.


  • Comprehensive explanations for each exercise and questions, promoting a deeper understanding of the subject.

  • Clear and structured presentation for easy comprehension.

  • Accurate answers aligned with the curriculum, boosting students' confidence in their knowledge.

  • Visual aids like diagrams and illustrations to simplify complex concepts.

  • Additional tips and insights to enhance students' performance.

  • Chapter summaries for quick revision.

  • Online accessibility and downloadable resources for flexible study and revision.


Chapter wise NCERT Solutions for Class 8 Science

 

Along with this, students can also view additional study materials provided by Vedantu, for Class 8 :


Conclusion

The NCERT Solutions for Class 8 Science Chapter 16 - Light, provided by Vedantu, is a valuable tool for Class 8 students. It helps introduce Science concepts in an accessible manner. The provided solutions and explanations simplify complex ideas, making it easier for Class 8 Students to understand the material. By using Vedantu's resources, Students can develop a deeper understanding of NCERT concepts. These solutions are a helpful aid for grade 8 students, empowering them to excel in their studies and develop a genuine appreciation for the chapter “Light”.

FAQs on NCERT Solutions for Class 8 Science Chapter 16 - Light

1. Mention which one of them will have a diffused reflection when exposed to strikes.

  • Polished table

  • Cardboard Surface

  • Mirror

  • Marble flooring

Reflection occurs only in the places that have plane surfaces and polished or even surfaces. Therefore, the mirror, marble flooring, and polished table will have reflections.

2. What are the Laws of Reflection?

The laws of reflection are stated below:

  • The incident ray, the reflected ray, and the normal ray all will lie in the same place.

  • The angle of incidence is equal to the angle of reflection.

3. What are the topics covered under NCERT Solutions for Class 8 Science Chapter 16?

Under Chapter 16 of Class 8 Science, several topics have been covered. These are all based on a basic understanding of Light. Questions like what makes things visible are discussed. On a more technical note, the laws of reflection are discussed along with regular and diffused reflection. The concept of multiple images is explained in simple terms. A basic layout of the structure of the eye is also given. To know more, visit the page NCERT Solutions Class 8 Science. 

4. What is the Braille system as discussed in the chapter?

The Braille system is defined as a helpful resource for visually challenged people that allows them to read and write. The system as it is presently used was adopted in the year 1932. There is unique Braille code that is different for common languages, for mathematics and for scientific notation. Many Indian languages can also be read by blind people by using the Braille system. 

5. Who is Helen Keller?

Helen Keller was a visually impaired girl who beat all odds to complete her graduation. She went on to author several books along with her autobiography named The Story Of My Life. Even though she lost her sight at the tender age of 18 months, this American author did not lose her courage. Her life is an inspiration to many blind people. 

6. How is reflected light useful?

Objects either radiate light of their own or they reflect it. Most objects simply reflect light. Nearly everything we see around us is visible solely due to reflected light. Even celestial bodies like the moon simply reflect the light of the sun, which is a luminous body that creates its own light source. For further clarity on this concept or to download NCERT solutions for free, visit the page NCERT Solutions Class 8 Science on the Vedantu website or download the Vedantu app. 

7. What are the benefits of using the NCERT Solutions for Class 8 Science Chapter 16?

Using Vedantu's NCERT Class 8 Science Chapter 16 Solutions helps acquaint students with the kind of questions that are important from the examination point of view. It also helps them identify weak points and topics that they might need to work more on. Practicing these questions regularly can yield great results and help students ace their school examinations. Visit the above page to access these solutions.