Sound Waves: Characteristics and Applications Worksheet for Class 9 Science helps students practice important concepts related to sound production, wave properties, reflection of sound, and its applications in daily life. This worksheet is prepared according to the CBSE Board syllabus to improve conceptual understanding and problem-solving skills.
Students can use these Worksheets for regular revision, homework practice, and exam preparation. The questions include short answers, reasoning-based problems, numerical questions, and application-based exercises to strengthen every important topic of the chapter.
Our collection of Class 9 Worksheets is designed to help students learn step-by-step by practising different question formats. These Class 9 Science Worksheets encourage students to apply concepts instead of only memorising definitions.
By solving this Sound Waves worksheet, students will understand how sound travels, how different characteristics of waves affect sound, and how technologies like SONAR and ultrasound use sound waves in real-life applications.
Download Class 9 Science Sound Waves Characteristics and Applications Worksheet PDF
Students can download the Class 9 Science Sound Waves Characteristics and Applications Worksheet PDF to practice important questions anytime. This printable worksheet helps students revise the chapter, solve numerical problems, and understand the practical applications of sound waves.
The worksheet PDF includes different types of questions based on the latest CBSE pattern, including short answer questions, calculation-based problems, competency-based questions, and real-life application questions. Students can use this worksheet for homework, classroom practice, or quick revision before exams.
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Sound Waves Characteristics and Applications Worksheet Questions
Section A: Very Short Answer Questions
1. Define sound.
2. What type of wave is a sound wave travelling through air?
3. Name the regions formed during the propagation of a longitudinal wave.
4. Write the SI unit of frequency.
5. What is meant by the amplitude of a sound wave?
6. Write the relation between frequency and time period.
7. What is the audible frequency range of a normal human ear?
8. Why can sound not travel through a vacuum?
9. Name one application of ultrasound.
10. What is the minimum time gap required to hear a clear echo?
Section B: Short Answer Questions
11. Explain how sound is produced by vibrating objects.
12. Differentiate between compression and rarefaction in a sound wave.
13. Why are sound waves called longitudinal waves?
14. Explain the relationship between wavelength, frequency, and speed of sound.
15. How does amplitude affect the loudness of sound?
16. Differentiate between high-pitched and low-pitched sounds.
17. Why does sound travel faster in solids than gases?
18. Explain two uses of ultrasound in daily life.
Section C: Numerical Questions
19. A sound wave has a frequency of 500 Hz and wavelength of 0.7 m. Calculate its speed.
20. Find the wavelength of a sound wave travelling at 340 m/s with frequency 170 Hz.
21. A person hears an echo after 2 seconds. If the speed of sound is 340 m/s, calculate the distance of the reflecting surface.
22. A SONAR device receives reflected sound waves after 4 seconds. Calculate the distance of an underwater object if the speed of sound in water is 1500 m/s.
23. Calculate the frequency of a wave having speed 300 m/s and wavelength 1.5 m.
Section D: Competency-Based Questions
24. A student notices that sound from a train reaches through railway tracks before it reaches through air. Explain the scientific reason behind this observation.
25. Doctors use ultrasound machines to observe internal organs of the human body. Explain why ultrasonic waves are suitable for this purpose.
26. Two musical instruments produce sounds of different frequencies. Explain how our ears identify the difference between these sounds.
27. A ship sends ultrasonic waves towards the ocean floor. Explain how this technique helps in finding ocean depth.
Section E: Case-Based Questions
Case Study 1:
A scientist sends a sound signal underwater. The reflected signal returns after some time. This method helps in detecting objects present deep inside the ocean.
Answer the following:
28. Name the technology based on this principle.
29. Which property of sound is used in this method?
30. Mention one practical use of this technology.
Case Study 2:
Sound waves are used in many medical and industrial fields. High-frequency sound waves can detect objects and create images that normal methods cannot.
Answer the following:
31. What are high-frequency sound waves called?
32. Give one medical application of these waves.
33. Why are these waves not audible to humans?
Sound Waves Characteristics and Applications Worksheet Answers
1. Sound is a form of energy produced by vibrating objects that creates a sensation of hearing when it reaches our ears.
2. Sound waves travelling through air are longitudinal waves because the particles of the medium vibrate parallel to the direction of wave propagation.
3. The two regions formed during the propagation of a longitudinal wave are compression and rarefaction.
4. The SI unit of frequency is Hertz (Hz).
5. Amplitude is the maximum displacement of a vibrating particle from its mean position. It determines the loudness of sound.
6. The relationship between frequency and time period is:
Frequency = 1 / Time Period
or
f = 1/T
Frequency and time period are inversely proportional to each other.
7. The audible frequency range of a normal human ear is from 20 Hz to 20,000 Hz.
8. Sound cannot travel through a vacuum because it requires a material medium such as solid, liquid, or gas for its propagation.
9. One application of ultrasound is medical imaging, where ultrasonic waves are used to create images of internal body organs.
10. The minimum time gap required to hear a clear echo is 0.1 seconds.
11. Sound is produced when objects vibrate. These vibrations create disturbances in nearby particles of the medium, which transfer energy from one particle to another in the form of sound waves.
12. Compression is the region of a longitudinal wave where particles are close together, creating high pressure and density. Rarefaction is the region where particles are spread apart, creating low pressure and density.
13. Sound waves are called longitudinal waves because the particles of the medium vibrate back and forth in the same direction as the movement of the wave.
14. The relationship between wavelength, frequency, and speed of sound is:
Speed = Wavelength × Frequency
v = λ × f
The speed of a sound wave depends on its wavelength and frequency.
15. Amplitude affects the loudness of sound. A sound wave with higher amplitude produces a louder sound, while lower amplitude produces a softer sound.
16. High-pitched sounds have higher frequencies, while low-pitched sounds have lower frequencies. Pitch helps us differentiate between sharp and deep sounds.
17. Sound travels faster in solids than gases because particles in solids are closely packed, allowing vibrations to transfer more quickly.
18. Two uses of ultrasound are:
It is used in medical imaging to examine internal organs.
It is used in industries to detect cracks or defects inside materials.
19. Given:
Frequency (f) = 500 Hz
Wavelength (λ) = 0.7 m
Formula:
v = λ × f
Calculation:
v = 0.7 × 500
Therefore, the speed of the sound wave is 350 m/s.
20. Given:
Speed (v) = 340 m/s
Frequency (f) = 170 Hz
Formula:
λ = v/f
Calculation:
λ = 340/170
Therefore, the wavelength of the sound wave is 2 m.
21. Given:
Time = 2 seconds
Speed of sound = 340 m/s
Formula:
Distance = (Speed × Time) / 2
Calculation:
Distance = (340 × 2) / 2
Therefore, the distance of the reflecting surface is 340 metres.
22. Given:
Time = 4 seconds
Speed of sound in water = 1500 m/s
Formula:
Distance = (Speed × Time) / 2
Calculation:
Distance = (1500 × 4) / 2
Therefore, the underwater object is at a distance of 3000 metres.
23. Given:
Speed = 300 m/s
Wavelength = 1.5 m
Formula:
Frequency = Speed / Wavelength
Calculation:
Frequency = 300 / 1.5
Therefore, the frequency of the sound wave is 200 Hz.
24. Sound reaches faster through railway tracks than air because sound travels faster in solids compared to gases. The closely packed particles in solids transfer vibrations more quickly.
25. Ultrasonic waves are suitable for medical purposes because they can travel inside the human body and produce images of internal organs without causing damage.
26. Our ears identify different musical sounds because of differences in frequency or pitch. A higher frequency produces a high-pitched sound, while a lower frequency produces a low-pitched sound.
27. Ships use SONAR technology to find ocean depth. SONAR sends ultrasonic waves that reflect back after hitting the ocean floor, and the time taken by the echo helps calculate the distance.
28. The technology based on sending and receiving reflected underwater sound waves is called SONAR (Sound Navigation and Ranging).
29. The property of sound used in this method is reflection of sound waves.
30. One practical use of SONAR is measuring ocean depth and locating underwater objects such as submarines.
31. High-frequency sound waves with frequencies above 20,000 Hz are called ultrasonic waves or ultrasound.
32. One medical application of ultrasonic waves is ultrasonography, which is used to create images of internal organs during medical diagnosis.
33. Ultrasonic waves are not audible to humans because their frequency is higher than the upper limit of the human hearing range, which is 20,000 Hz.
What is Included in Sound Waves Characteristics and Applications Worksheet?
This Class 9 Science worksheet provides a complete practice structure covering important areas of the chapter.
Students will practice:
- Very short answer questions for quick revision
- Short answer questions based on important concepts
- Formula-based numerical problems
- Reasoning and application-based questions
- Competency-based questions following CBSE exam patterns
- Real-life applications of sound waves
- Answer key for checking responses
The worksheet focuses on improving understanding of concepts rather than just remembering answers.
Important topics covered:
- Production and propagation of sound
- Longitudinal sound waves
- Compression and rarefaction
- Frequency, wavelength, amplitude, and time period
- Speed of sound
- Reflection of sound
- Echo and reverberation
- Ultrasound and SONAR applications
Important Concepts Practiced
After completing this worksheet, students will strengthen the following concepts:
- How sound is produced by vibrations
- Requirement of medium for sound propagation
- Nature of longitudinal waves
- Difference between compression and rarefaction
- Characteristics of sound waves
- Relationship between frequency, wavelength, and speed
- Calculation-based sound problems
- Reflection of sound waves
- Working principle of echo
- Uses of SONAR and ultrasound technology
These concepts help students build a strong foundation for advanced Physics topics.
Key Takeaways from Sound Waves Characteristics and Applications
- Sound is a mechanical wave that requires a medium to travel.
- Sound travels through solids, liquids, and gases but not through a vacuum.
- Sound waves in air are longitudinal waves.
- Frequency controls the pitch of sound.
- Amplitude affects the loudness of sound.
- The speed of a wave depends on wavelength and frequency.
- Reflection of sound is used in technologies like SONAR.
- Ultrasound has important applications in medicine and industries.
- Regular worksheet practice improves numerical and conceptual understanding.
