CBSE 9 Science | 11. Sound by Akhil | Learn Smarter with Allrounder.ai
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11. Sound

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Sections

  • 11

    Sound

    This section explores the nature, production, propagation, and characteristics of sound as a form of energy.

    Learning Practice

  • 11.1

    Production Of Sound

    Sound is produced by the vibration of objects, which can be observed and measured through specific experiments.

    Learning Practice

  • 11.2

    Propagation Of Sound

    Sound propagates through solids, liquids, and gases as a mechanical wave generated by vibrating objects.

    Learning Practice

  • 11.2.1

    Sound Waves Are Longitudinal Waves

    This section explains that sound travels as longitudinal waves through a medium, characterized by compressions and rarefactions of particles.

    Learning Practice

  • 11.2.2

    Characteristics Of A Sound Wave

    This section explores the essential characteristics of sound waves, including frequency, amplitude, and speed, along with their significance.

    Learning Practice

  • 11.2.3

    Speed Of Sound In Different Media

    The speed of sound varies in different media depending on their physical properties, primarily temperature.

    Learning Practice

  • 11.3

    Reflection Of Sound

    This section covers the concept of sound reflection, focusing on how sound waves bounce off surfaces and the phenomena of echoes and reverberation.

    Learning Practice

  • 11.3.1

    Echo

    This section introduces the concept of echoes, discussing how sound reflects off surfaces and the necessary conditions for a distinct echo to be heard.

    Learning Practice

  • 11.3.2

    Reverberation

    Reverberation refers to the persistence of sound in a space due to repeated reflections from surfaces.

    Learning Practice

  • 11.3.3

    Uses Of Multiple Reflection Of Sound

    Multiple reflection of sound has practical applications, including megaphones, stethoscopes, and echoes.

    Learning Practice

  • 11.4

    Range Of Hearing

    The section discusses the audible range of sound for humans and other animals, defining infrasound and ultrasound, and their significance.

    Learning Practice

  • 11.5

    Applications Of Ultrasound

    Ultrasounds are high-frequency sound waves widely utilized in medical and industrial fields for a variety of applications, including imaging and cleaning.

    Learning Practice

References

NCERT Study Material

Class Notes

Memorization

Revision Tests

Chapter FAQs