Chapter 9, Problem 33R

To determine

The correct option.

Answer to Problem 33R

The correct option is C.

Explanation of Solution

Introduction:

Longitudinal waves make rarefaction ad compression region.

The region where particle density is higher is called compression region and the region where particle density is lesser is called rarefaction region.

The region X is the rarefaction region because the density in that region is lesser as compared to the other regions.

Crest is the highest point in the wave but here region X is not the highest position, region adjacent to X is compression as the particles are compressed.

Trough is the lowest point in a sine wave, this is not a sign wave.

Thus, a, b and d are incorrect.

Conclusion:

Therefore, the correct option is C.