Question 1

What is sound?

Accepted Answer

Sound is a form of energy that produces a sensation of hearing in our ears. It is produced by vibrating bodies and travels in the form of mechanical waves through a medium.

Question 2

How is sound produced?

Accepted Answer

Sound is produced by the vibration of objects. When an object vibrates, it sets the surrounding medium particles into vibration, thus producing sound waves.

Question 3

Which type of waves are sound waves in air?

Accepted Answer

Sound waves in air are longitudinal waves because the particles of the medium vibrate in the direction parallel to the direction of propagation of the disturbance.

Question 4

What is the region of high pressure in a longitudinal wave called?

Accepted Answer

The region of high pressure and high density created in a longitudinal wave is called compression (C).

Question 5

Which of the following mediums does sound travel fastest in?

Accepted Answer

Sound travels fastest in solids because the particles are closely packed, allowing rapid transfer of vibrational energy compared to liquids and gases.

Sound — CBSE Class 9 Science Important Questions & Revision Notes