Which among the following is true for propagation of sound waves ?
[amp_mcq option1=”Sound can travel in vacuum and it is a transverse wave in air.” option2=”Sound cannot travel in vacuum and it is a longitudinal wave in air.” option3=”Sound can travel in vacuum and it is a longitudinal wave in air.” option4=”Sound cannot travel in vacuum and it is a transverse wave in air.” correct=”option2″]
This question was previously asked in
UPSC NDA-2 – 2021
The correct option is B. Sound waves are mechanical waves that require a medium to propagate and cannot travel through a vacuum. In air, sound waves are longitudinal waves, meaning the particles of the medium vibrate parallel to the direction of wave propagation.
Sound transmission involves the vibration of particles in a medium. In air, this vibration creates regions of compression and rarefaction that travel through the air as a wave. Because the particle displacement is along the direction of energy propagation, it is a longitudinal wave. Vacuum lacks the particles needed to transmit these vibrations, hence sound cannot travel in a vacuum.