Question

Sound is called longitudinal wave because

• A. sound need a material medium for propagation
• B. the molecules of the medium oscillate to and fro about their mean position in the direction of propagation
• C. sound waves moves in the direction of its production
• D. all reasons are correct

Answer 1

The correct option is B the molecules of the medium oscillate to and fro about their mean position in the direction of propagation

When a sound travels through its medium, the molecules in the air oscillate to and fro about their mean positions in the direction of propagation of the sound wave. Hence it is a longitudinal wave.