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NCERT Solutions for Class 8 Science Chapter 10 Sound

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Class 8 Science Chapter 10 Sound Question and Answer - FREE PDF Download

In Class 8 Science Chapter 10 - "Sound," we delve into the fascinating world of sound waves and their properties. This chapter thoroughly explains how living organisms produce, transmit, and perceive sound. From exploring the nature and types of sound to learning about the human ear and its functions, Sound Class 8 covers all essential aspects of sound clearly and comprehensively. By downloading the Sound Chapter Class 8 PDF Questions And Answers, students can thoroughly grasp the key principles presented in the curriculum. 

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Download the FREE PDF of the NCERT Solutions for Class 8 Science prepared by Vedantu Master Teachers, which is updated according to the Class 8 Science syllabus. Start with Vedantu to pursue a path of academic excellence!


Quick Insights for Class 8 Science Chapter 10 Question Answer

  • Sound Chapter Class 8 PDF explores the fascinating world of sound, exploring its nature, propagation, and various characteristics.

  • Class 8 Science Chapter Sound explains how sound is produced, transmitted, and received, covering concepts like vibration, frequency, amplitude, and wavelength.

  • Class 8 Science Ch 10 delves into the mechanisms of sound production in different musical instruments, human speech, and the functioning of the human ear.

  • Sound Chapter Class 8 Question And Answer thoroughly explains all topics, ensuring students are well-prepared for exams.

  • Utilising these Class 8 Science Chapter 10 Question Answers helps students evaluate their understanding and master the concept of sound production, transmission, and reception concepts.

  • Vedantu offers additional resources such as class notes, important concepts, diagrams, and exemplar solutions to enhance learning and ensure a solid grasp of fundamental scientific principles.

Access NCERT Solutions for Science Class 8 Chapter 10 – Sound

1. Choose the correct answer.

Sound can travel through

  1. gases only

  2. solids only

  3. liquids only

  4. solids, liquids and gases.

Ans: (d) solids, liquids and gases.

Sound can travel in any medium.


2. Which of the following voices is likely to have minimum frequency?

  1. Baby girl

  2. Baby boy

  3. A man

  4. A woman

Ans: (c) A man

Frequency of a sound is directly proportional to pitch. Here, the pitch of a man is minimum.


3. In the following statements, tick ‘T’ against those which are true, and ‘F’ against those which are false.

a) Sound cannot travel in vacuum.

Ans: T

Vacuum is an enclosed place in which there are no molecules or matter. Therefore, sound cannot travel through a vacuum where there is no molecule or atom to induce vibrations.


b) The number of oscillations per second of a vibrating object is called its time period.

Ans: F

The number of oscillations per second of a vibrating object is known as its frequency. 


c) If the amplitude of vibration is large, sound is feeble.

Ans: F

Sound is feeble for small amplitudes.


d) For human ears, the audible range is \[20\] Hz to \[20,000\] Hz.

Ans: T

For human ears, the audible range is \[20\] Hz to \[20,000\] Hz.


e) The lower the frequency of vibration, the higher is the pitch.

Ans: F

The pitch of a sound is proportional to its frequency. As the frequency of vibration increases, the pitch of the sound also increases and vice versa.


f) Unwanted or unpleasant sound is termed as music.

Ans: F

Unwanted or unpleasant sounds are known as noise. 


g) Noise pollution may cause partial hearing impairment.

Ans: T

If one is subjected to loud unpleasant sound continuously for a long time, then it may cause temporary hearing impairment.


4. Fill in the blanks with suitable words.

a) Time taken by an object to complete one oscillation is called _________.

Ans: Time taken by an object to complete one oscillation is called time period.


b) Loudness is determined by the ________ of vibration.

Ans: Loudness is determined by the amplitude of vibration.


c) The unit of frequency is _________.

Ans: The unit of frequency is hertz (Hz).


d) Unwanted sound is called _________.

Ans: Unwanted sound is called noise.


e) Shrillness of a sound is determined by the _________ of vibration.

Ans: Shrillness of a sound is determined by the frequency of vibration.


5. A pendulum oscillates \[40\] times in \[4\] seconds. Find its time period and frequency.

Ans: Time period is defined as the time required to complete one oscillation.

Frequency is defined as the number of oscillations per unit time.

Here,

Time \[t=4s\]

Number of oscillations \[n=40\]

Frequency \[f=\dfrac{n}{t}\]

Thus, \[f=\dfrac{40}{4}\]

\[\therefore f=10\] Hz

Time period is the inverse of frequency of an object.

Therefore, \[T=\dfrac{1}{f}\]

\[T=\dfrac{1}{10}\]

\[\therefore T=0.1s\]


6. The sound from a mosquito is produced when it vibrates its wings at an average rate of \[500\] vibrations per second. What is the time period of the vibration?

Ans: Time period is the inverse of frequency of an object.

Therefore, \[T=\dfrac{1}{frequency}\]

\[T=\dfrac{1}{500}\]

\[\therefore T=0.002s\]


7. Identify the part which vibrates to produce sound in the following instruments.

a) Dholak

Ans: Dholak has stretched membranes called heads that vibrate to produce sound.


b) Sitar

Ans: In sitar, the stretched strings are plucked and when they vibrate, they produce sound.


c) Flute

Ans: In flute, the air column inside it vibrates when blown which produces sound.


8. What is the difference between noise and music? Can music become noise sometimes?

Ans: Noise is an unpleasant sound which is a result of irregular vibrations. Music is a sound which is pleasant to hear. Yes, music can sometimes become noise when it is played at very high volumes on loudspeakers.


9. List sources of noise pollution in your surroundings.

Ans: Following are the major sources of noise pollution:

  1. Sounds of vehicle horns.

  2. Explosions that include bursting of crackers and explosives.

  3. Sounds of machines and loudspeakers.

  4. Sounds of television and transistor radio at high volumes.

  5. Sounds of kitchen appliances.


10. Explain in what way noise pollution is harmful to humAns:

Ans: Noise pollution is harmful to humans as it may cause many health-related problems; like insomnia, hypertension, headache, stress and may even lead to loss of hearing.


11. Your parents are going to buy a house. They have been offered one on the roadside and another three lanes away from the roadside. Which house would you suggest your parents should buy? Explain your answer.

Ans: I would suggest that the house be three lanes away from the roadside because the house next to the roadside will be more noisy compared to the house three lanes away from the road.


12. Sketch the larynx and explain its function in your own words.

Ans: Larynx is a part of the throat. It moves when we swallow something. There are two vocal cords inside the Larynx. The air passes through a small gap between them. The lungs force the air into the space when we speak and this vibrates the vocal cord, resulting in the production of sound. That is why the larynx is also known as a sound box.


Side and Top view of Larynx new


Side and Top view of Larynx new


13. Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain why? 

Ans: Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later because speed of light is greater than the speed of sound and therefore, light travels faster than thunder.


Sound Chapter Class 8 - Quick Overview of Topics Covered 

S.No.

Topics of Sound Class 8

1

Sound is Produced by a Vibrating Body

2

Sound Produced by Humans

3

Sound Needs a Medium for Propagation 

4

We Hear Sound through Our Ears

5

Amplitude, Period, and Frequency of a Vibration

6

Loudness and Pitch

7

Audible and Inaudible Sounds

8

Noise and Music

9

Noise Pollution

10

What are the Harms of Noise Pollution? 

11

Measures to Limit Noise Pollution



Important Points for Class 8 Science Chapter 10- Sound

  1. Sound is produced by vibrating objects.

  2. Vibration is the rapid back-and-forth movement of an object.

  3. Sound travels through a medium (solid, liquid, or gas) by compressing and rarefying particles.

  4. It cannot travel through a vacuum as no particles transmit the vibrations.

  5. Sound travels at different speeds in different media: fastest in solids, slower in liquids, and slowest in gases. 

  6. Characteristics of Sound

  • Frequency: Number of vibrations per second, measured in Hertz (Hz). Determines the pitch of the sound.

  • Amplitude: Height of the sound wave. Determines the loudness of the sound.

  • Wavelength: Distance between two consecutive compressions or rarefactions.

  • Time Period: The time taken for one complete vibration.

  1. Human Ear

  • The ear converts sound waves into electrical signals which are interpreted by the brain.

  • Parts of the ear: Outer ear (collects sound), Middle ear (amplifies sound), Inner ear (transmits sound to the brain).

  1. Noise: Unpleasant, irregular, and random sound waves.

  2. Music: Pleasant, regular, and harmonic sound waves.

  3. Sound Pollution

  • Excessive or unwanted sound can have harmful effects on health and the environment.

  • Reducing sound pollution includes using soundproof materials, regulating noise levels, and planting trees.


Benefits of Vedantu’s NCERT Sound Chapter Class 8 PDF

  • Class 8 Science Chapter Sound Question Answer clearly explains all the questions discussed in the chapter.

  • Sound Chapter Class 8 PDF Questions And Answers covers important concepts related to sound, including its production, propagation, properties, and effects.

  • Class 8 Science Chapter Sound delves into the mechanisms of sound production in different musical instruments, human speech, and the functioning of the human ear.

  • Sound Chapter Class 8 Question And Answer short question answers assist students in completing their last-minute revisions efficiently and effectively.

  • Sound Class 8 incorporates practice questions and exercises that allow students to test their understanding of sound concepts. This practice reinforces learning and prepares students for exams.

  • By referring to NCERT Solutions of Sound Chapter Class 8, students can effectively prepare for exams as the solutions cover all the topics and questions likely to be asked in assessments.


Conclusion

Vedantu’s NCERT Solutions for Class 8 Science Ch 10, Sound is essential for understanding the fundamental concepts of sound, such as its production, propagation, and properties. These solutions simplify complex topics, making it easier for students to grasp key ideas. Focusing on understanding how sound travels through different mediums and the characteristics of sound waves is crucial. The previous year’s question paper featured 7-8 questions from this chapter, emphasising its importance in exams. By studying these solutions, students can effectively prepare, ensuring they have a strong grasp of the material and are ready to excel in their exams.  


Important Study Materials For Class 8 Science Chapter 10

For more insights, students can also download additional study materials provided by Vedantu for Chapter 10, Sound Class 8-


Chapter-wise Links for NCERT Solutions for Class 8 Science


Study Material Links for Class 8 Science

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FAQs on NCERT Solutions for Class 8 Science Chapter 10 Sound

1. What is the main concept covered in NCERT Solutions for Class 8 Science Chapter 10 Sound?

NCERT Solutions for Class 8 Science Chapter 10 Sound mainly focus on understanding how sound is produced, transmitted, and received. The chapter explains the concepts of vibration, characteristics of sound waves (like frequency, amplitude, wavelength), production of sound in humans and instruments, and the effects of noise pollution, following the CBSE 2025–26 syllabus.

2. How is sound produced according to NCERT Class 8 Science Chapter 10?

According to NCERT Class 8 Science Chapter 10 Sound, sound is produced when a body vibrates. These vibrations cause the surrounding medium (solid, liquid, or gas) to move in compressions and rarefactions, creating sound waves that travel to our ears.

3. Why can sound not travel through a vacuum?

Sound cannot travel through a vacuum because there are no molecules or particles to transmit the vibrations. Sound requires a medium (such as air, water, or solids) for transmission, as explained in the NCERT Solutions for Class 8 Science Chapter 10 Sound.

4. What is the role of the larynx (voice box) in sound production in humans?

The larynx, or voice box, contains vocal cords that vibrate when air from the lungs passes through them. These vibrations produce sound, which is then modified by the mouth, tongue, and lips to form speech.

5. How does frequency affect the pitch of sound as per CBSE guidelines?

The frequency of a sound wave determines its pitch. A higher frequency produces a higher pitch, and a lower frequency produces a lower pitch. For example, the voice of a man has a lower frequency and hence a lower pitch compared to that of a baby, as stated in the NCERT Solutions for Class 8 Science Chapter 10.

6. What is noise pollution, and what are its adverse effects according to the NCERT Solutions Class 8 Science Sound chapter?

Noise pollution is the presence of unwanted or harmful sounds in the environment. Its adverse effects include:

  • Hearing impairment
  • Stress and irritability
  • Sleep disturbances (insomnia)
  • Increased blood pressure
  • Reduced concentration and productivity
These are covered as per CBSE 2025–26 Science Class 8 Chapter 10.

7. What are the key differences between noise and music as outlined in Class 8 NCERT Solutions?

Music is a pleasant, harmonic sound produced by regular vibrations, while noise is an unpleasant, irregular sound due to erratic vibrations. At high volumes, even music can become noise and cause discomfort.

8. What is the audible range of human hearing according to Chapter 10 of Class 8 Science?

The audible range for humans is from 20 Hz to 20,000 Hz. Sounds outside this range are called infrasonic (below 20 Hz) or ultrasonic (above 20,000 Hz), as described in the NCERT Solutions for Sound Class 8.

9. How do musical instruments produce sound based on NCERT Solutions for Class 8 Science Chapter 10?

Different musical instruments produce sound through vibrating parts:

  • Membranes (e.g., drums like dholak)
  • Strings (e.g., sitar)
  • Air columns (e.g., flute)
These vibrations generate sound waves that we hear.

10. What is meant by amplitude and how does it affect sound as per Class 8 Science NCERT Solutions?

Amplitude is the height of the sound wave from its mean position. A larger amplitude means louder sound, while a smaller amplitude means softer or feeble sound.

11. If the frequency of a sound increases, what happens to its pitch and why?

When the frequency increases, the pitch of the sound also increases. This happens because pitch is directly proportional to frequency, as explained in the CBSE Class 8 Science curriculum for 2025–26.

12. What measures can be taken to reduce noise pollution as suggested in NCERT Solutions for Sound Chapter Class 8?

To reduce noise pollution, one should:

  • Limit the use of loudspeakers and firecrackers
  • Maintain vehicles and machine parts
  • Use soundproofing materials in buildings
  • Plant trees along roads and around homes
  • Keep television and audio device volume low

13. What would happen if sound could travel through a vacuum, and how does this relate to real-life scenarios?

If sound could travel through a vacuum, we would be able to hear sounds in space. However, in real life, astronauts use radios because sound requires a medium to travel, which is absent in the vacuum of space, as discussed in Class 8 Science NCERT Solutions.

14. How does the human ear detect and interpret sound according to Chapter 10 Sound NCERT Solutions?

The human ear detects sound by:

  • Outer ear collects sound waves
  • Middle ear amplifies vibrations
  • Inner ear converts vibrations into electrical impulses
  • Brain interprets these impulses as sound
This process ensures we understand different sounds as per the CBSE Class 8 Science syllabus.

15. Why is it important to prepare from NCERT Solutions for Class 8 Science Chapter 10 for CBSE exams?

NCERT Solutions for Class 8 Science Chapter 10 strictly follow the latest CBSE exam pattern and syllabus. They provide accurate, stepwise explanations for all textbook questions, helping students develop a strong conceptual foundation and score higher in their 2025–26 board assessments.