NCERT Solutions | Class 8 Science Chapter 13 | Sound

CBSE Solutions | Science Class 8

Check the below NCERT Solutions for Class 8 Science Chapter 13 Sound Pdf free download. NCERT Solutions Class 8 Science were prepared based on the latest exam pattern. We have Provided Sound Class 8 Science NCERT Solutions to help students understand the concept very well.

NCERT | Class 8 Science

NCERT Solutions Class 8 Science
Book:	National Council of Educational Research and Training (NCERT)
Board:	Central Board of Secondary Education (CBSE)
Class:	8th
Subject:	Science
Chapter:	13
Chapters Name:	Sound
Medium:	English

Sound | Class 8 Science | NCERT Books Solutions

You can refer to MCQ Questions for Class 8 Science Chapter 13 Sound to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

NCERT TEXTBOOK EXERCISES

ncert science class 8 Chapter 13, Question 1.

Choose the correct answer:
Sound can travel through
(a) gases only
(b) solids only
(c) liquids only
(d) solids, liquids and gases

cbse science class 8 solutions, Answer :

(d) solids, liquids and gases.

ncert science class 8 pdf free download, Question 2.

Voice of which of the following is likely to have minimum frequency?
(a) Baby girl
(b) Baby boy
(c) A man
(d) A woman

ncert class 8 science Chapter 13 question answer, Answer :

(b) Baby boy.

ncert science class 8 solutions, Question 3.

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

Sound cannot travel in a vacuum. (T/F)
The number of oscillations per second of a vibrating object is called its time period. (T/F)
If the amplitude of vibration is large, the sound is feeble. (T/F)
For human ears, the audible range is 20 Hz to 20,000 Hz. (T/F)
The lower the frequency of vibration, the higher is the pitch. (T/F)
Unwanted or unpleasant sound is termed music. (T/F)
Noise pollution may cause partial hearing impairment. (T/F)

cbse science class 8 solutions, Answer :

True
False
False
True
False
False
True

ncert science class 8 textbook pdf, Question 4.

Fill in the blanks with suitable words:

Time taken by an object to complete one oscillation is called…….
Loudness is determined by the………..of vibration.
The unit of frequency is………….
Unwanted sound is called……….
The shrillness of a sound is determined by the.……….of vibration.

ncert class 8 science Chapter 13 question answer, Answer :

time period
amplitude
Hertz (Hz)
noise
frequency.

NCERT Solutions for Class 8 Science, Question 5.

A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency.

cbse science class 8 solutions, Answer :

NCERT Solutions for Class 8 Science Chapter 13 Sound 1

NCERT Solutions for Class 8 Science Chapter 13, Question 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?

ncert class 8 science Chapter 13 question answer, Answer :

Number of vibrations per second = 500
Time period = time is taken for one vibration
NCERT Solutions for Class 8 Science Chapter 13 Sound 2

science class 8 Chapter 13, Question 7.

Identify the part which vibrates to produce sound in the following instruments:

Dholak
Sitar
Flute

cbse science class 8 solutions, Answer :

Stretched membrane
String of sitar
Air column.

science class 8 pdf, Question 8.

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

ncert class 8 science Chapter 13 question answer, Answer :

The unpleasant sound is called noise, whereas a pleasant sound is called music. Noise can produce so many health hazards, whereas music brings about a soothing effect. Yes, music can become noise sometimes when the musical instruments produce very high volume sounds.

cbse class 8 science book, Question 9.

List sources of noise pollution in your surroundings.

cbse science class 8 solutions, Answer :

Following are the major sources of noise pollution:

Sounds of vehicles.
Sounds of the bursting of crackers and explosives.
Sounds of loudspeakers, TVs, transistors.
Sounds of kitchen appliances.
Sounds of desert coolers, air conditioners etc.

cbse class 8 science Chapter 13, Question 10.

Explain in what way noise pollution is harmful to humans.

ncert class 8 science Chapter 13 question answer, Answer :

Noise pollution may cause many health-related problems.

Lack of sleep, hypertension (high blood pressure), anxiety, etc. are some of the problems that may be caused due to noise pollution.
A person who is exposed to a loud sound continuously may get temporary or even permanent deafness.

cbse class 8 science notes pdf, Question 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.

cbse science class 8 solutions, Answer :

I would suggest my parents buy the house which is three lanes away from the roadside. This would protect us from noise pollution which is maximum on the roadside.

cbse class 8 science syllabus pdf, Question 12.

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

ncert class 8 science Chapter 13 question answer, Answer :

In humans, the sound is produced by the voice box or the larynx. It is situated in the throat. Below it is the windpipe. The two vocal cords are stretched across the voice box or larynx in such a way that it leaves a narrow slit between them for the passage of air when the lungs force air through the slit, the vocal cords vibrate and the vibration results in sound.
NCERT Solutions for Class 8 Science Chapter 13 Sound 3

NCERT Solutions for Class 8 Science Chapter 13 Sound 3

cbse science class 8 book, Question 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?

cbse science class 8 solutions, Answer :

The light travels at the speed of 3 x 10s ms-1, which is very large in comparison to the speed of sound which travels at the rate of 330 ms-1 in the air. That is why lightning is seen earlier and thunder is heard later.