Question

Which of the following does not allow sound propagation?

• A. vacuum
• B. steel
• C. air
• D. water

Answer 1

The correct option is A

vacuum

Explanation of correct option: In the case of option(A),

1. Sound requires a material medium to propagate.
2. In a medium, molecules will be present that can be compressed and expanded in space which in turn facilitates sound propagation.
3. Since vacuum does not have molecules, sound propagation is not possible.

Explanation of incorrect option: In the case of options (B), (C), and (D),

Steel, air, and water contain molecules that can vibrate and facilitate the propagation of sound waves.

Hence, option (A) is the correct answer.