Introduction to Sound || Sound - 1 || in Hindi for Class 9

In this Science (Physics) video in Hindi for Class 9 we explained what sound is, how it is generated and propagated, why it needs a material medium to propagate. We also explained what compression and rarefaction are. This is a topic from Chapter 12 - 'Sound' for class 9th from NCERT.

When a body vibrates, it also oscillates the surrounding air column that, in turn, oscillates the next column and so on. In this way energy is being transfered and this disturbance is called a wave.

A wave is a disturbance in a medium that transfers energy progressively from one point to another point in that medium.

Sound is a longitudinal wave.

Longitudinal waves are waves in which the displacement of the particles of the medium is in the same direction as, or the opposite direction to, the direction of propagation of the wave.

In the process of propagation, sound generates compressed air column somewhere, which is called compression and in some places it creates expanded air column, which is called rarefaction.

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🔴 Click here to watch the whole playlist on Chapter 12 : 'Sound' for Class 9 :
   • Characteristics of a sound wave || Sound -...  

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Related videos :-

🔴 Sound is produced by a vibrating object
   • Видео  

🔴 Longitudinal Wave demonstration
   • Видео  

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