Question

1. which is a correct way to measure wavelength? from rarefaction to rarefaction for a longitudinal wave from rest position to crest for a transverse wave from compression to rarefaction for a longitudinal wave from crest to trough for a transverse wave

Explanation:

The wavelength of a longitudinal wave can be measured from compression - to - compression or rarefaction - to - rarefaction. For a transverse wave, it is measured from crest - to - crest, trough - to - trough or any two identical points on the wave. Measuring from rest position to crest gives the amplitude of a transverse wave. Measuring from compression to rarefaction for a longitudinal wave or from crest to trough for a transverse wave does not measure the wavelength.

Answer:

A. from rarefaction to rarefaction for a longitudinal wave