CBSE Class 8 Science Sound Assignment Set A

Read and download free pdf of CBSE Class 8 Science Sound Assignment Set A. Get printable school Assignments for Class 8 Science. Standard 8 students should practise questions and answers given here for Chapter 13 Sound Science in Grade 8 which will help them to strengthen their understanding of all important topics. Students should also download free pdf of Printable Worksheets for Class 8 Science prepared as per the latest books and syllabus issued by NCERT, CBSE, KVS and do problems daily to score better marks in tests and examinations

Assignment for Class 8 Science Chapter 13 Sound

Class 8 Science students should refer to the following printable assignment in Pdf for Chapter 13 Sound in standard 8. This test paper with questions and answers for Grade 8 Science will be very useful for exams and help you to score good marks

Chapter 13 Sound Class 8 Science Assignment

Sound

Question 1: How does the sound produced by a vibrating object in a medium reach your ear?
Answer- When a disturbance is created on an object, it starts vibrating and sets the particles of the medium to vibrate. These vibrating particles take the sound from object to our ear through the medium.
 
Question 2: Explain how sound is produced by your school bell.
Answer- When the school bell is struck with a hammer, it starts vibrating and as a result of these vibrations,sound waves are produced.
 
Question 3: Why are sound waves called mechanical waves?
Answer- Because sound waves require a medium to propagate to interact with the particles present in it.
 
Question 4: Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend?
Answer- No, we will not be able to hear the sound because sound requires a medium for its propagation. On the moon there is no atmosphere, i.e., there is vacuum.
 
Question 5: Which wave property determines (a) loudness, (b) pitch?
Answer- (a) Loudness is determined by the amplitude of the sound wave which in turn depends on the force with which the object is made to vibrate.
(b) Pitch of a sound is determined by its frequency.
 
Question 6: Guess which sound has a higher pitch: guitar or car horn?
Answer- Guitar.
 
Question 7: What are wavelength, frequency, time period and amplitude of a sound wave?
Answer-(a) Wavelength(λ) : The distance between two consecutive compressions (C) or two consecutive rarefactions (R) is called the wavelength, unit-metre.
(b) Frequency : The number of oscillations per unit time is called frequency, unit-Hz.
(c) Time period : The time taken by two consecutive compressions or rarefactions to cross a fixed point is called the time period.
(d) Amplitude : The magnitude of the maximum disturbance in the medium on either side of the mean value is called the amplitude of the wave.
 
Question 8: How are the wavelength and frequency of a sound wave related to its speed?
Answer- Speed = Wavelength x Frequency.
 
Question 9: Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.
Answer- Frequency = f = 220 Hz

Speed of sound = v = 440 m/s

Wavelength = λ = v/f = 440/220 = 2 m.
 
Question 10: A person is listening to a tone of 500 Hz sitting at a distance of 450 m from the source of the sound. What is the time interval between successive compressions from the source?
Answer- Frequency = f = 500 Hz
Time between successive compressions = Time period of sound wave = T = 1/f = 1/500 = 0.002 sec.
 
Question 11: Distinguish between loudness and intensity of sound.
Answer-
                         Loudness of sound                                                         Intensity of sound
1. Loudness refers to how loud or soft a sound seems to a listener.    1. Intensity is defined as the power carried by sound waves per unit area.
2. Loudness of sound is determined of amplitude.                             2. Intensity of the sound wave is determined by frequency of sound waves.
3. The unit of loudness is the decibel (dB).                                       3. The unit of intensity of sound is watt per square meter (W/m2).
 
Question 12: In which of the three media, air, water or iron, does sound travel the fastest at a particular temperature?
Answer- Iron (Solid).
 
Question 13: Why are the ceilings of concert halls curved?
Answer- Ceilings of concert halls are curved to uniformly spread sound in all directions after reflecting from the walls.
 
Question 14: What is the audible range of the average human ear?
Answer- 20 Hz to 20,000 Hz.
 
Question 15: What is the range of frequencies associated with (a) Infrasound? (b) Ultrasound?
Answer- (a) Infrasound: Less than 20 Hz ; (b) Ultrasound: More than 20000 Hz

 

More Question

I. Fill in the blanks.

1. To and fro or back and forth motion of an object is called ___________.

2. In humans the sound is produced by the ________ or the ___________.

3. ________ are stretched across the voice box or larynx.

4. The vocal cords in men are about ______ mm long.

5. Noise becomes physically painful at _____ dB.

6. Frequency determines the ________ of a sound.

7. ________ on the roadside and elsewhere can reduce noise pollution.

8. _________ and _______ are two important properties of sound.

9. ________ senses the vibrations of sound.

II. Name the following

1. An instrument used for investigating and tracking many medical problems.

2. Name the major causes of noise pollution.

3. Name the sources in home which may lead to noise.

4. Give examples of objects which produce sounds of low frequency or low pitched.

5. Give examples of objects which produce sound of high frequency or high pitched.


Some Natural Phenomena

Q1. What type of electric charge is acquired by a rubber balloon when rubbed with a woolen cloth?

Q2. A positively charged object repels another charged object kept close to it. What is the nature of charge on the other object?

Q3. A glass rod is rubbed with a silk cloth & a rubber balloon is rubbed with a woolen cloth.

a) Which two objects acquire negative charge?

b) Which two objects acquire positive charge?

Q4. Explain why, a glass rod can be charged by rubbing when held by hand but an iron rod cannot be charged by rubbing, if held by hand?

Q5. Consider three charged bodies P, Q & R. If P & Q repel each other & P attracts R. What is the nature of force between Q & R?

Q6. Name the device used to detect electric charge on a body. Draw its labeled diagram.

Q7. What will you observe when the metal cap of an electroscope is touched with a glass rod which has been rubbed with silk cloth? Give reason for your answer.

Q8. What are the uses of an electroscope? (3 points)

Q9. Why do the leaves of a gold leaf electroscope diverge when a charged body is brought in contact with its disc?

Q10. Do the leaves of an electroscope always diverge to the same extent when a charged body is brought in contact with its disc?

Q11. What will you observe when the metal cap of an electroscope is touched with:

a) A positively charged object?

b) A negatively charged object?


Click on link below to download CBSE Class 8 Science Sound Assignment Set A

More Study Material

Where can I download in PDF assignments for CBSE Class 8 Science Chapter 13 Sound

You can download free Pdf assignments for CBSE Class 8 Science Chapter 13 Sound from StudiesToday.com

The assignments for Chapter 13 Sound Class 8 Science for have been made based on which syllabus

The Chapter 13 Sound Class 8 Science Assignments have been designed based on latest CBSE syllabus for Class 8 Science issued for the current academic year

Can I download and print these printable assignments for Science Chapter 13 Sound Class 8

Yes, These printable assignments for Chapter 13 Sound Class 8 Science are free to download and print

How many topics are covered in Chapter 13 Sound Science assignments for Class 8

All topics given in Chapter 13 Sound Science Class 8 Book for the current academic year have been covered in the given assignment

Is there any charge for this assignment for Chapter 13 Sound Science Class 8

No, all Printable Assignments for Chapter 13 Sound Class 8 Science have been given for free and can be downloaded in Pdf format

How can I download the printable test assignments for Chapter 13 Sound Science Class 8

Just click on the View or Download button below, then another window with the Pdf will be visible, just click on the Pdf icon to download the free assignments for Chapter 13 Sound Class 8 Science

Are these assignments available for all chapters in Class 8 Science

Yes, apart from Science you can download free assignments for all subjects in Class 8

Can I download solved assignments for Chapter 13 Sound CBSE Class 8 Science

Our team of expert teachers at studiestoday.com have provided all answers for the practice questions which have been given in Class 8 Science Chapter 13 Sound assignments