Question

When a longitudinal wave is incident at the boundary of denser medium, then ___________.

• A. Compression reflects as a compression
• B. Compression reflects as a rarefaction
• C. Rarefaction reflects as a compression
• D. Longitudinal wave reflects as transverse wave

Answer 1

The correct option is A Compression reflects as a compression

On reflection from a denser medium, a change of phase by ${180}^{\circ }$ takes place for a transverse wave. However no such change occurs for a longitudinal wave.

Hence on reflection of longitudinal wave from a denser medium, a compression remains a compression, and a rarefaction as rarefaction.