Question

which of the boxes represents the wavelength of a wave?
neither
b
a
both

Explanation:

The wavelength of a wave is the distance between two consecutive points that are in - phase (e.g., from crest to crest or trough to trough). In the given wave diagram, box B represents the distance between two consecutive crests (or troughs), which is the definition of wavelength. Box A represents the amplitude (the maximum displacement from the equilibrium position), and box C may represent something else (not relevant to wavelength). So only box B represents the wavelength.

Answer:

B. B