Sound Waves: Characteristics and Applications-Assignments - What Have You Learned? Science Exploration Class 9 In English-CBSE Notes


Last Updated : August 2, 2026

Explore NCERT Solutions for Class 9 science exploration Chapter Sound Waves: Characteristics and Applications Topic Assignments - What Have You Learned? with simple explanations and free ncert solution in English.

Class 9 Science Exploration Exploration Chapter 10 Sound Waves: Characteristics and Applications Assignments - What Have You Learned?

Popular Topics Covered

Our study material includes

  • cbse notes for class 9 science exploration chapter Sound Waves: Characteristics and Applications topic Assignments - What Have You Learned? in english
  • class 9 science exploration chapter Sound Waves: Characteristics and Applications cbse notes
  • cbse class 9 science exploration chapter Sound Waves: Characteristics and Applications notes in english
  • class 9 science exploration chapter Sound Waves: Characteristics and Applications study notes
  • class 9 science exploration chapter Sound Waves: Characteristics and Applications revision notes
  • cbse notes for class 9 science exploration chapter Sound Waves: Characteristics and Applications
  • class 9 science exploration chapter Sound Waves: Characteristics and Applications summary notes
  • cbse class 9 science exploration chapter Sound Waves: Characteristics and Applications quick notes

All Topics Chapter Sound Waves: Characteristics and Applications

Notes

Sound Waves: Characteristics and Applications-Assignments - What Have You Learned? Science Exploration Class 9 In English-CBSE Notes

Sound Waves: Characteristics and Applications

Page 8 of 8

Assignments - What Have You Learned?

Chapter 10. Sound Waves: Characteristics and Applications

This assignment covers all the important concepts of the chapter, including the production and propagation of sound, characteristics of sound waves, speed of sound, reflection of sound, echo, reverberation, ultrasound and SONAR. The questions follow the latest CBSE competency-based assessment pattern. 

1. One Word Answer

  1. The form of energy produced by vibrating objects.
  2. The type of wave through which sound travels.
  3. The region of high pressure in a sound wave.
  4. The region of low pressure in a sound wave.
  5. The SI unit of frequency.
  6. The quantity that determines the loudness of sound.
  7. The quantity that determines the pitch of sound.
  8. The phenomenon of bouncing back of sound.
  9. The device used to detect underwater objects using sound.
  10. Sound having a frequency greater than 20,000 Hz.

2. Fill in the Blanks

  1. Sound is produced due to __________ of objects.
  2. Sound cannot travel through a __________.
  3. Sound travels fastest in __________.
  4. The SI unit of frequency is __________.
  5. The time period of a wave is represented by __________.
  6. Echo is produced due to the __________ of sound.
  7. Ultrasonic waves have frequencies greater than __________ Hz.
  8. SONAR works on the principle of __________ of sound.
  9. Loudness depends on the __________ of vibration.
  10. Pitch depends on the __________ of vibration.

3. True or False

  1. Sound can travel through vacuum.
  2. Sound is a longitudinal mechanical wave.
  3. Compressions are regions of low pressure.
  4. Frequency is measured in hertz.
  5. Greater amplitude produces louder sound.
  6. Echo and reverberation are the same phenomenon.
  7. Ultrasonic waves can be heard by humans.
  8. SONAR is mainly used underwater.
  9. Sound transfers energy but not matter.
  10. Bats use ultrasonic waves for navigation.

4. Match the Following

Column A Column B
Compression High Pressure Region
Rarefaction Low Pressure Region
Frequency Hertz (Hz)
Amplitude Loudness
Reflection of Sound Echo
Ultrasound Frequency Above 20 kHz
SONAR Underwater Detection
Vacuum No Sound Propagation
Longitudinal Wave Particle Motion Parallel to Wave
Pitch Frequency

5. Very Short Answer Questions

  1. Define sound.
  2. Why is sound called a mechanical wave?
  3. Name the two regions of a longitudinal wave.
  4. What is wavelength?
  5. Define frequency.
  6. What is amplitude?
  7. State one condition required to hear an echo.
  8. What is reverberation?
  9. What is ultrasound?
  10. Expand the term SONAR.

6. Short Answer Questions

  1. Explain how sound is produced.
  2. Describe the Bell Jar Experiment and its conclusion.
  3. Differentiate between compression and rarefaction.
  4. Explain the propagation of sound through a medium.
  5. Describe the characteristics of sound waves.
  6. Differentiate between loudness and pitch.
  7. Explain the factors affecting the speed of sound.
  8. State the laws of reflection of sound.
  9. Differentiate between echo and reverberation.
  10. Explain the working principle of SONAR.

7. Long Answer Questions

  1. Describe the production and propagation of sound with suitable diagrams.
  2. Explain longitudinal waves with the help of compressions and rarefactions.
  3. Describe wavelength, frequency, time period, amplitude and speed of sound.
  4. Explain reflection of sound and discuss its applications.
  5. Describe echo and reverberation along with their differences.
  6. Explain ultrasonic waves and their applications.
  7. Describe the construction and working of SONAR.
  8. Discuss the importance of sound waves in science, medicine and technology.

8. Case Study Questions

Case Study – 1

A student places an electric bell inside a glass bell jar. As the air is gradually removed from the jar, the ringing sound becomes weaker and finally cannot be heard, although the bell continues to vibrate.

  1. What does this experiment prove?
  2. Why does the sound disappear?
  3. Can sound travel through vacuum?
  4. Name the type of wave produced by the bell.

Case Study – 2

A boy shouts loudly near a hill and hears the same sound again after a short interval.

  1. Name the phenomenon observed.
  2. What causes this phenomenon?
  3. State one condition necessary for hearing it.
  4. Give one practical application of this phenomenon.

Case Study – 3

A dolphin emits ultrasonic waves while swimming underwater. The reflected waves help it detect nearby objects.

  1. Which type of sound is used?
  2. Why can't humans hear these waves?
  3. Which device works on the same principle?
  4. State one more application of ultrasonic waves.

Case Study – 4

A sound wave has a frequency of 500 Hz and a wavelength of 0.68 m.

  1. Calculate the speed of the sound wave.
  2. Write the formula used.
  3. Which characteristic determines the pitch?
  4. Which characteristic determines the loudness?

Case Study – 5

An auditorium is fitted with curtains, carpets and cushioned seats.

  1. Which sound phenomenon is reduced by these materials?
  2. Why is it necessary to reduce this phenomenon?
  3. Name two sound-absorbing materials used in auditoriums.
  4. How does this improve the quality of sound?

9. Competency-Based Questions

  1. Why is vibration necessary for the production of sound?
  2. Explain why astronauts cannot hear each other directly in space.
  3. Why does sound travel faster in solids than in gases?
  4. How does amplitude affect the loudness of sound?
  5. Why does frequency determine the pitch of sound?
  6. Explain why echo is not heard in a small classroom.
  7. How does reverberation affect speech in large halls?
  8. Why are ultrasonic waves preferred for medical imaging?
  9. How does SONAR help ships navigate safely underwater?
  10. Explain how sound transfers energy without transferring matter.

10. HOTS Questions

  1. Why is sound classified as a mechanical longitudinal wave?
  2. A sound wave travels from air into water. Which properties change and which remain unchanged? Explain.
  3. Why is thunder heard after lightning, even though both occur at the same time?
  4. How does the design of an auditorium improve the quality of sound?
  5. Compare echo and reverberation with suitable real-life examples.
  6. Explain why bats can fly safely in complete darkness.
  7. How does ultrasound help detect internal defects in metal blocks?
  8. A submarine uses SONAR to detect an underwater object. Explain the principle involved.
  9. How would communication be affected if sound could travel through vacuum?
  10. Prepare a flow chart showing the sequence: Vibration → Sound Wave → Propagation → Reflection → Echo → Ultrasound → SONAR.
Page 8 of 8

All Topics Chapter Sound Waves: Characteristics and Applications

✨ You May Also Like This!

View Related Article

NCERT MATHS Solutions

Sound Waves: Characteristics and Applications-Assignments - What Have You Learned? Science Exploration Class 9 In English-CBSE Notes


Hindi Medium Students/Teachers/Tutors:

All Chapters science exploration Class 9

CBSE Notes for Class 9 science exploration Chapter Sound Waves: Characteristics and Applications – Assignments - What Have You Learned?

The CBSE Notes for Class 9 science exploration Chapter Sound Waves: Characteristics and Applications – Assignments - What Have You Learned? are prepared to help students understand every concept in a simple, clear, and well-organized manner. These notes are based on the latest CBSE syllabus and are suitable for regular classroom learning, homework, revision, and examination preparation. Every topic is explained using easy language so that students can learn important concepts without difficulty and develop a strong academic foundation.

Studying directly from the textbook is essential, but during revision students often need concise study material that highlights only the most important information. These chapter-wise notes provide exactly that. Instead of reading lengthy chapters repeatedly, students can quickly revise definitions, concepts, facts, examples, and important points in a short period of time. This approach saves valuable study time while improving understanding and retention.

Why Study Chapter Sound Waves: Characteristics and Applications – Assignments - What Have You Learned? Using Our Notes?

Every chapter contains several important concepts that require careful understanding. Our notes present these concepts in a logical sequence so students can connect ideas easily. Difficult topics are simplified with easy explanations, making learning enjoyable for students of different learning abilities. Whether you are preparing for classroom discussions, assignments, periodic tests, or annual examinations, these notes provide a reliable source for effective revision.

✨ You May Also Like This!

View Related Article

NCERT Social Science Solutions
  • Prepared according to the latest CBSE curriculum.
  • Simple and student-friendly explanations.
  • Chapter-wise organized content for easy learning.
  • Important concepts, definitions, and key points included.
  • Useful for quick revision before examinations.
  • Supports self-study and classroom learning.
  • Helps improve conceptual understanding and confidence.
  • Suitable for homework, assignments, and test preparation.

Benefits of Reading CBSE Notes Regularly

Consistent revision is one of the most effective ways to achieve academic success. Reading CBSE Notes for Class 9 science exploration Chapter Sound Waves: Characteristics and Applications – Assignments - What Have You Learned? regularly helps students remember important information for a longer period. Since the content is arranged systematically, students can identify important topics quickly and revise them whenever required.

These notes also help students improve answer-writing skills by presenting information in a structured format. Instead of memorizing lengthy paragraphs, students learn how to organize answers using important points and concepts. This not only improves writing quality but also increases confidence during examinations.

How to Use These Notes Effectively

To get the best results, students should first read the NCERT textbook carefully and understand the chapter. After completing the textbook, they should study these notes to reinforce important concepts. During revision, students can focus on highlighted definitions, important facts, and key ideas before solving textbook exercises and practice questions. This learning strategy improves both understanding and long-term memory.

Teachers and parents can also use these notes as a quick reference while helping students revise lessons or complete assignments. Since the content is concise and well-organized, it becomes easier to explain difficult topics within a limited amount of time.

Features of Our CBSE Notes

Every chapter on our platform is created with the objective of making learning easier for students. Our educational team regularly reviews and updates the content according to the latest CBSE guidelines so that students always receive reliable and accurate study material.

  1. Easy-to-understand chapter explanations.
  2. Important definitions and key concepts.
  3. Well-structured content for faster revision.
  4. Based on the latest CBSE syllabus.
  5. Helpful for school exams and annual examinations.
  6. Free online access on desktop and mobile devices.

Prepare Better with Chapter-wise CBSE Notes

Success in examinations depends on consistent practice and smart revision. These CBSE Notes for Class 9 science exploration Chapter Sound Waves: Characteristics and Applications – Assignments - What Have You Learned? are designed to reduce study pressure by presenting important information in a concise and meaningful way. Students can use them throughout the academic session for daily learning as well as last-minute revision before examinations.

Along with these notes, students are encouraged to solve NCERT textbook questions, practice important questions, and attempt sample papers regularly. Combining concept-based learning with regular practice helps improve problem-solving ability, analytical thinking, and overall academic performance. With disciplined study habits and quality learning resources, students can build confidence, strengthen their understanding of every chapter, and achieve excellent results in school examinations.

 

Sound Waves: Characteristics and Applications-Assignments - What Have You Learned? Science Exploration Class 9 In English-CBSE Notes Study Materials For Class 6 to 12

If you want to improve your academic performance, start studying with free CBSE notes for all classes. These notes are designed to make learning simple, clear, and effective for every student. Choose your class, explore the chapters, and begin your preparation with the latest cbse notes today.

Frequently Asked Questions (FAQs)

What are NCERT Solutions for Class 9?
NCERT Solutions for Class 9 provide step-by-step answers to all textbook questions. These solutions help students understand concepts clearly and prepare effectively for exams.
Why are NCERT Solutions for Class 9 important?
NCERT Solutions for Class 9 help students understand textbook questions, improve conceptual knowledge, and prepare well for school and board exams.
Are NCERT Solutions for Class 9 free?
Yes, NCERT Solutions for Class 9 available on this page are completely free for students to use anytime.
Do NCERT Solutions for Class 9 follow the latest CBSE syllabus?
Yes, these NCERT Solutions for Class 9 are prepared according to the latest CBSE syllabus and exam pattern.
How do NCERT Solutions for Class 9 help in exams?
NCERT Solutions for Class 9 improve concept clarity, help students practice important questions, and improve answer writing skills.
Can I download NCERT Solutions for Class 9 in PDF?
Yes, many chapters of NCERT Solutions for Class 9 are available in PDF format for easy download and offline study.
Which subjects are included in NCERT Solutions for Class 9?
NCERT Solutions for Class 9 include subjects such as Science, Mathematics, Social Science, English, and Hindi.
Are NCERT Solutions for Class 9 useful for competitive exams?
Yes, NCERT Solutions for Class 9 help build a strong conceptual foundation which is useful for many competitive exams.
How should students study using NCERT Solutions for Class 9?
Students should first try solving the questions themselves and then check NCERT Solutions for Class 9 to verify their answers.
Where can I find chapter wise NCERT Solutions for Class 9?
You can find chapter-wise NCERT Solutions for Class 9 on this page to easily study and revise each chapter.