How is wavelength measured?

Wavelength is defined as the distance between two consecutive points of the same phase in a wave. This is commonly interpreted as the distance between two crests (the highest points) or two troughs (the lowest points), which each represent the same part of the wave cycle. Therefore, the correct answer to how wavelength is measured can accurately reflect the distance from the beginning of a peak (a crest) to the end of a valley (which comes after that peak).

This measurement captures the full cycle of the wave, indicating how waves propagate through space. Including both the crest and valley in the measurement ensures that one encompasses the entirety of a wave's cycle. Such a definition is essential in fields like radar and telecommunications, where understanding wavelengths is crucial for effective signal transmission and reception.

The other choices, while partially relevant, do not fully encapsulate the standard definition of wavelength. For example, measuring from crest to crest would also be correct but does not represent the diverse context offered by measuring the complete cycle. Similarly, measuring from trough to trough is accurate but is less commonly used compared to measuring from crest to crest or peak to valley. The notion of measuring from pulse to pulse does not apply to wavelength in a conventional sense and is typically a concept associated more