Question

Which of the following statements is/are correct?

• A. A compression in a longitudinal wave is represented by a crest in pressure-distance graph.
• B. A compression in a longitudinal wave is represented by a trough in pressure-distance graph.
• C. A rarefaction in a longitudinal wave is represented by a crest in pressure-distance graph.
• D. A rarefaction in a longitudinal wave is represented by a trough in pressure-distance graph.

Answer 1

Answer: (A), (D)

The correct options are
A A compression in a longitudinal wave is represented by a crest in pressure-distance graph.
D A rarefaction in a longitudinal wave is represented by a trough in pressure-distance graph.

A compression is a region of high pressure and a rarefaction is a region of low pressure in a longitudinal wave. Thus, a compression is represented by a peak, i.e., crest in pressure-distance graph. Similarly, a rarefaction is represened by a trough.