CBSE Class 8 Science Sound Assignment Set B

Read and download free pdf of CBSE Class 8 Science Sound Assignment Set B. Get printable school Assignments for Class 8 Science. Class 8 students should practise questions and answers given here for Chapter 13 Sound Science in Class 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 Class 8. This test paper with questions and answers for Class 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: What is sound and how is it produced?
Answer- Sound is a form of energy and it is produced due to vibrations of different types of objects.
 
Question 2: Describe with the help of a diagram, how compressions and rarefactions are produced in the air near a source of sound.
Answer- (1) When a vibrating object moves forward, it pushes the air in front of it and compresses the air creating a region of high pressure called compression (C).
(2) It starts moving away from the surface of the vibrating object.
(3) As this occurs the surface moves backward creating a region of low pressure called rarefaction (R)

8th.sci.eng.oct.nov.21.22 9


Question 3: Cite an experiment to show that sound needs a material medium for its propagation.
Answer- Take an electric bell and an air tight glass bell jar. The electric bell is suspended inside an air tight glass jar which is connected to a vacuum pump. Working:
1. When we press the switch, we will be able to hear the bell
2. When the air in the jar is pumped out gradually, the sound becomes feeble although the same amount of current is flowing through the bell.
3. When the air is removed completely, are will not be able to hear the sound of the bell.
Conclusion: This experiment shows that sound requires a medium for its propagation.
 
Question 4: Why sound wave is called a longitudinal wave?
Answer- A sound wave is called a longitudinal wave as it travels in a medium by the vibration of particles in a direction which is parallel to the direction of propagation of the sound wave.
 
Question 5: Which characteristics of the sound help you to identify your friend by his voice while sitting with others in a dark room?
Answer- The quality (or timbre), pitch and loudness of sound.
 
Question 6: Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why?
Answer- The speed of light is much higher than speed of sound. Due to this reason, the thunder takes more time to reach the Earth as compared to the light. Hence, lightning is seen before whenever we hear the thunder
 
Question 9: The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?
Answer- Frequency = 100 Hz
Number of vibrations in 1 second = 100
Number of vibrations in 60 second = 100 x 60
Number of vibrations in 1 minute = 6000.
 
Question 10: Does sound follow the same laws of reflection as light does? Explain.
Answer- Yes, sound follows the same laws of reflection as light does because,
(1) Angle of incidence of sound is always equal to angle of reflection of sound waves.
(2) The direction in which sound is incident, the direction in which it is reflected and normal all lie in the
same plane.
 
Question 11: When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same. Do you hear echo sound on a hotter day?
Answer- An echo is heard when time interval between the reflected sound and the original sound is at least 0.1 second. As the temperature increases, the speed of sound in a medium also increases. On a hotter day, the time interval between the reflected and original sound will decrease and an echo is audible only if the time interval between the reflected sound and the original sound is greater than 0.1 s.
 
Question 12: Give two practical applications of reflection of sound waves.
Answer- (i) Reflection of sound is used to measure the speed and distance of underwater objects. This method is called SONAR.
(ii) Working of a stethoscope - the sound of patient’s heartbeat reaches the doctor’s ear through multiple reflections of sound.
 
Question 15: What is reverberation? How can it be reduced?
Answer- The continuous multiple reflections of sound in a big enclosed space is reverberation. It can be reduced by covering walls and ceiling of enclosed space with the help of sound absorbing materials such as loose woollens, fibre boards.
 
Question 16: What is loudness of sound? What factors does it depend on?
Answer- Loudness refers to how loud or soft a sound seems to a listener. Loudness of sound is determined of amplitude. The unit of intensity is the decibel (dB).
 
Question 17: Explain how bats use ultrasound to catch prey.
Answer- The ultrasonic waves emitted by the bat are reflected from the prey (e.g., an insect) and are detected by its ears . The nature of reflected waves tells the bat about the location and the nature of its prey.
 
Question 18: How is ultrasound used for cleaning?
Answer- Objects that need to be cleansed are put in a cleaning solution and ultrasonic sound waves are passed through the solution. The high frequency of ultrasound waves helps in detaching the dirt from the objects.
 
Question 19: Explain the working and application of a SONAR.
Answer- SONAR;(-Sound Navigation and Ranging).It consists of a transmitter and a detector and is installed in a boat or a ship as shown in figure:

8th.sci.eng.oct.nov.21.22 11


More Question

Q.1 How does a sound making object differ from one that is silent?

Q.2 How does sound from a sound producing body travel through air to reach our ears?

Q.3 Why are the voices of men, Women and children different?

Q.4 Why a sound cannot be heard on the moon?

Q.5 How do astronauts talk to one another on the surface of moon and Why?

Q.6 If you want to hear a train approaching from far away, why is it more convenient to put the ear to the track?

Q.7 State one observation from everyday life which shows that sound travels much more slowly than light?

Q.8 What is the scientific name for the following?

The number of vibrations made per second.

Q.9 Why do we not hear the screams of a bat?

Q.10 Which of the following frequency of sound can be heard by a dog but not by a man? {a} 50,000 hertz {b} 15,000 hertz

Q.11 Explain how, noise pollution {or excessive loud noise} is harmful to human beings.

Q.12 State the various measures which can be taken to control {or reduce} noise pollution in our surroundings.

Q.13 Give two causes of noise pollution from the homes.

Q.14 Sound of different pitch can be produced using a flute. Explain, how?

 

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

More Study Material

CBSE Class 8 Science Chapter 13 Sound Assignment

We hope you liked the above assignment for Chapter 13 Sound which has been designed as per the latest syllabus for Class 8 Science released by CBSE. Students of Class 8 should download and practice the above Assignments for Class 8 Science regularly. We have provided all types of questions like MCQs, short answer questions, objective questions and long answer questions in the Class 8 Science practice sheet in Pdf. All questions have been designed for Science by looking into the pattern of problems asked in previous year examinations. 

Assignment for Science CBSE Class 8 Chapter 13 Sound

Our team of expert teachers have referred to NCERT book for Class 8 Science to design the Science Class 8 Assignments. If you practice at least one test paper daily, you will get higher marks in Class 8 exams this year. Daily practice of Science course notes and related study material will help you to clear all your doubts and have stronger understanding of all concepts. You can download all Revision notes for Class 8 Science also from www.studiestoday.com absolutely free of cost.

Chapter 13 Sound Assignment Science CBSE Class 8

All questions and their answers for the assignment given above for Class 8 Science have been developed as per the latest curriculum and books issued for the current academic year. The students of Class 8 can rest assured that the best teachers have designed the questions of Science so that you are able to revise the entire syllabus if you do the assignments. Lot of MCQ questions for Class 8 Science have also been given in the worksheets and assignments for regular use. All study material for Class 8 Science students have been given on studiestoday.

Chapter 13 Sound Assignment CBSE Class 8 Science

Regular assignment practice helps to get a more comprehensive understanding of Chapter 13 Sound concepts. Assignments play a crucial role in understanding Chapter 13 Sound in CBSE Class 8. Students can download all the assignments of the same chapter in Class 8 Science in Pdf format. You can print them or read them online on your computer or mobile.

CBSE Science Class 8 Chapter 13 Sound Assignment

CBSE Class 8 Science latest books have been used for coming up with the latest questions and solutions for the above assignment. If you have revised all concepts relating to Chapter 13 Sound then you should attempt all questions given in the test sheets above. We have also provided lot of Worksheets for Class 8 Science which you can use to further make your self stronger in Science

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