Question

Which of these is not a medium for propagation of sound?
(a)vacuum
(b)water
(c)Air
(d)steel

Answer 1

Answer:

vacuum is not a medium for propagation of sound

Answer 2

A. Vacuum, as sound waves are longitudinal in nature

Explanation:

1. Waves may be divided into two categories. Longitudinal and transverse waves.
2. Transverse waves: Waves that cause vibrations in a medium in a direction that is perpendicular to their propagation (eg. Light).
3. Longitudinal waves: These waves have the same direction of propagation as the vibrations produced in the medium. Sound waves are longitudinal, they cannot move in a vacuum.