Question

In sound waves, the individual particles of the medium move in which direction w.r.t direction of propagation of the disturbance?
A. parallel
B. perpendicular
C. angular
D. do not move

Answer 1

Hint: A sound wave is a disturbance caused in a medium due to continuous compression and rarefaction of the particles in the medium. Sound waves are longitudinal waves. A longitudinal wave is a type of wave in which the oscillations of the particle are parallel with the direction of the propagation of the wave.

Complete answer:
A wave is a disturbance in a medium, which travels in a particular direction . It is produced to the oscillatory motion of the particles in that medium. For example, when we disturb a tightly held string, when we observe waves in that string. A sound wave is a disturbance caused in a medium due to continuous compression and rarefaction of the particles in the medium.

Due to the compressions and rarefactions, a pressure difference is produced in the medium. As a result, sound waves are also called pressure waves. Sound waves are longitudinal waves. A longitudinal wave is a type of wave in which the oscillations of the particle are parallel with the direction of the propagation of the wave. Therefore, in a sound wave, the individual particles of the medium oscillate in the direction parallel with the direction of the propagation of the disturbance.

Hence, the correct option is A.

Note: When a wave is produced at a point, it propagates it the direction away from the point of origin. We can easily observe this in water. If we disturb the water surface at a point, water waves (called ripples) are produced at that point, which travel in the outward direction.Since a wave propagates in a particular direction, there is transfer of energy from one point to another.