NCERT Solutions for Science Class 8 Chapter 13 – Sound
Orchid International School offers a convenient solution to enhance your study experience with well-crafted NCERT Solutions for Class 8 Science. You can now access the official website to download the PDF of NCERT Solutions for Class 8 Science Chapter 13. This resource allows you to comprehensively revise Chapter 13 of Class 8 Science.
Download PDF For NCERT Solutions for Science Sound
The NCERT Solutions for Science Class 8 Chapter 13 – Sound are tailored to help the students master the concepts that are key to success in their classrooms. The solutions given in the PDF are developed by experts and correlate with the CBSE syllabus of 2023-2024. These solutions provide thorough explanations with a step-by-step approach to solving problems. Students can easily get a hold of the subject and learn the basics with a deeper understanding. Additionally, they can practice better, be confident, and perform well in their examinations with the support of this PDF.
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Access Answers to NCERT Solutions for Science Class 8 Chapter 13 – Sound
Students can access the NCERT Solutions for Science Class 8 Chapter 13 – Sound. Curated by experts according to the CBSE syllabus for 2023–2024, these step-by-step solutions make Science much easier to understand and learn for the students. These solutions can be used in practice by students to attain skills in solving problems, reinforce important learning objectives, and be well-prepared for tests.
Sound
Choose the correct answer.
Sound can travel through
-
gases only
-
solids only
-
liquids only
-
solids, liquids and gases.
4 .solids, liquids and gases.
Sound can travel in any medium.
Which of the following voices is likely to have minimum frequency?
-
Baby girl
-
Baby boy
-
A man
-
A woman
3 . A man
Frequency of a sound is directly proportional to pitch. Here, the pitch of a man is minimum.
In the following statements, tick ‘T’ against those which are true, and ‘F’ against those which are false.
a) Sound cannot travel in vacuum.
b) The number of oscillations per second of a vibrating object is called its time period.
c) If the amplitude of vibration is large, sound is feeble.
d) For human ears, the audible range is
20
20
Hz to
20,000
20,000
Hz.
e) The lower the frequency of vibration, the higher is the pitch.
f) Unwanted or unpleasant sound is termed as music.
g) Noise pollution may cause partial hearing impairment.
a) . 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) .F
The number of oscillations per second of a vibrating object is known as its frequency.
c) . F
Sound is feeble for small amplitudes.
d) . T
For human ears, the audible range is
20
20
Hz to
20,000
20,000
Hz.
e) . 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.
g) . T
If one is subjected to loud unpleasant sound continuously for a long time, then it may cause temporary hearing impairment.
Fill in the blanks with suitable words.
a) Time taken by an object to complete one oscillation is called _________.
b) Loudness is determined by the ________ of vibration.
c) The unit of frequency is _________.
d) Unwanted sound is called _________.
e) Shrillness of a sound is determined by the _________ of vibration.
a) . Time taken by an object to complete one oscillation is called time period.
b) . Loudness is determined by the amplitude of vibration.
c) .The unit of frequency is hertz (Hz).
d) . Unwanted sound is called noise.
e) . Shrillness of a sound is determined by the frequency of vibration.
A pendulum oscillates
40
40
times in
4
4
seconds. Find its time period and frequency.
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
�=4�
Number of oscillations
n=40
�=40
Frequency
f=
n
t
�=��
Thus,
f=
40
4
�=404
∴f=10
∴�=10
Hz
Time period is the inverse of frequency of an object.
Therefore,
T=
1
f
�=1�
T=
1
10
�=110
∴T=0.1s
∴�=0.1�
The sound from a mosquito is produced when it vibrates its wings at an average rate of
500
500
vibrations per second. What is the time period of the vibration?
Time period is the inverse of frequency of an object.
Therefore,
T=
1
frequency
�=1���������
T=
1
500
�=1500
∴T=0.002s
∴�=0.002�
Identify the part which vibrates to produce sound in the following instruments.
a) Dholak
b) Sitar
c) Flute
a) . Dholak has stretched membranes called heads that vibrate to produce sound.
b) .In sitar, the stretched strings are plucked and when they vibrate, they produce sound.
c) . In flute, the air column inside it vibrates when blown which produces sound.
What is the difference between noise and music? Can music become noise sometimes?
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.
List sources of noise pollution in your surroundings.
Following are the major sources of noise pollution:
-
Sounds of vehicle horns.
-
Explosions that include bursting of crackers and explosives.
-
Sounds of machines and loudspeakers.
-
Sounds of television and transistor radio at high volumes.
-
Sounds of kitchen appliances.
Explain in what way noise pollution is harmful to humans:
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.
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.
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.
Sketch the larynx and explain its function in your own words.
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
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?
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.
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Frequently Asked Questions
The NCERT solution for Class 8 Chapter 13 : Sound is important as it provides a structured approach to learning, ensuring that students develop a strong understanding of foundational concepts early in their academic journey. By mastering these basics, students can build confidence and readiness for tackling more difficult concepts in their further education.
Yes, the NCERT solution for Class 8 Chapter 13 : Sound is quite useful for students in preparing for their exams. The solutions are simple, clear, and concise allowing students to understand them better. They can solve the practice questions and exercises that allow them to get exam-ready in no time.
You can get all the NCERT solutions for Class 8 Science Chapter 13 from the official website of the Orchids International School. These solutions are tailored by subject matter experts and are very easy to understand.
Yes, students must practice all the questions provided in the NCERT solution for Class 8 Science Chapter 13 : Sound as it will help them gain a comprehensive understanding of the concept, identify their weak areas, and strengthen their preparation.
Students can utilize the NCERT solution for Class 8 Science Chapter 13 effectively by practicing the solutions regularly. Solve the exercises and practice questions given in the solution.