Chapter 12 Sound

Sensation of hearing is sound with our ears we can listen different kind of sound and even we understand the difference between them but we don't know actual science behind the sound so this chapter make us cleare how of sound originate, it propagates, its quality and many more. You may have also heard the animals like elephant dogs etc can feel natural calamities like earthquake before it commencement what the reason behind this lets understand.

Download pdf of NCERT Solutions for Class Science Chapter 12 Sound

Download pdf of NCERT Examplar with Solutions for Class Science Chapter 12 Sound

Exercise 1

  • Q1 How does the sound produced by a vibrating object in a medium reach your ear?

    When a disturbance is created on an object, it starts vibrating and sets the particles of the medium to vibrate. These vibrating particles then force the particles adjacent to them to vibrate. As a result, the adjacent particle is disturbed from its mean position and the original particle comes back to rest. This process continues till the disturbance reaches our ears.

Exercise 2

Exercise 3

Exercise 4

Exercise 5

  • Q1 Distinguish between loudness and intensity of sound.

    Intensity of a sound wave is not a physical quantity which can be accurately measured. It does not depend upon the sensitivity of the ear. Loudness is not an entirely physical quantity. The loudness of a sound is defined by its amplitude. The amplitude of a sound decides its intensity, which in turn is perceived by the ear as loudness.

Exercise 6

Exercise 7

Exercise 8

  • Q1 Why are the ceilings of concert halls curved?

    Concert halls are very big, so the sound might not reach every corner of the hall. Ceilings of concert halls are curved so that sound after reflection spreads uniformly in all parts of the hall.

Exercise 9

Exercise 10

Exercise 11

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