NCERT Class 9 Science Exploration: Chapter 10 — 10. Sound Waves: Characteristics and Applications
This chapter, '10. Sound Waves: Characteristics and Applications,' from NCERT's Class 9 Science Exploration book, delves into the fundamental aspects of sound. It begins by highlighting sound as a crucial sensory experience that informs us about our surroundings, listing various everyday sounds. The chapter revisits the concept that sound is a form of energy, emphasizing that energy transforms but is never lost. It poses questions about the conversion of energy to sound and how sound is produced and perceived. The core of the chapter focuses on the production of sound, explaining that sound originates from vibrations. Through activities and examples like musical instruments and vocal cords, it illustrates how vibrating objects, strings, membranes, air columns, and vocal cords generate sound. The chapter also touches upon how humans and animals produce sound, concluding that sound is inextricably linked to vibration. This foundational understanding is essential for comprehending sound's behavior and its applications in the physical world, aiding students in their CBSE science curriculum.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 9 |
| Subject | Science |
| Book | Exploration |
| Chapter | Chapter 10 — 10. Sound Waves: Characteristics and Applications |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 4 minutes |
| Word count | 677 |
Learning outcomes
- Understand that sound is a form of energy produced by vibrations.
- Identify various sources of sound in everyday life.
- Explain how sound is produced in musical instruments and the human voice.
- Recognize the role of vibrations in sound production.
- Differentiate between vibrating and non-vibrating objects in relation to sound.
Vocabulary
| Word | Meaning |
|---|---|
| Vibration | The periodic to and fro motion (oscillations) of an object. |
| Source of sound | The object that produces sound. |
| Sonority | A property of some metals where sound is produced when struck with an object. |
| Vocal cords | Tightly stretched muscular flaps inside the voice box (larynx) that vibrate to produce sound in humans and some animals. |
| Larynx | The voice box in the throat where vocal cords are located. |
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Practice questions
- What is sound? Answer: 10. Sound Waves: Characteristics and Applications is a form of energy that helps us become aware of our surroundings.
- How is sound produced? Answer: 10. Sound Waves: Characteristics and Applications is produced by vibrations of objects.
- Give an example of a musical instrument that produces sound through vibrating strings. Answer: A guitar or a sitar produces sound through vibrating strings.
- What are vocal cords and where are they located? Answer: Vocal cords are tightly stretched muscular flaps located inside the voice box or larynx in the throat.
- What happens to sound when the vibration stops? Answer: When the vibration stops, the sound also stops.
Frequently asked questions
What is the relationship between sound and energy?
10. Sound Waves: Characteristics and Applications is a form of energy that is produced by vibrations.
How do astronauts communicate in space?
Astronauts communicate using radio waves, as sound cannot travel in a vacuum.
Can bats use sound to locate prey?
Yes, most bats use a form of sound called echolocation to locate their prey in the dark.
What causes sound?
10. Sound Waves: Characteristics and Applications is caused by the vibration of objects.
How do humans produce sound?
Humans produce sound by the vibration of their vocal cords located in the larynx.
What is vibration?
Vibration is the rapid back and forth movement of an object.
Related resources
Important topics
Topics covered
NCERT Class 9 Science — Exploration — Chapter 10 — 10. Sound Waves: Characteristics and Applications. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.