AFOQT Practice Test

What is the wavelength of a wave?

1. The height of the wave

2. Distance between crests (or troughs) of waves

3. Time taken for a wave to complete one cycle

4. Number of waves that occur in a specific time

The correct answer is: Distance between crests (or troughs) of waves

The correct understanding of the wavelength of a wave is indeed the distance between crests (or troughs) of waves. Wavelength is defined as the spatial period of a periodic wave, which is the distance over which the wave's shape repeats. It is measured as the distance between successive peaks (crests) or troughs, highlighting its significance in characterizing any type of wave, including sound and electromagnetic waves. The other aspects mentioned in the options serve different purposes related to wave behavior. For example, the height of the wave corresponds to the amplitude, which indicates the wave's energy rather than the distance between crests. The time taken for a wave to complete one cycle refers to the wave's period, providing insight into its frequency but not directly measuring wavelength. Finally, the number of waves that occur in a specific time relates to frequency, indicating how many wavelengths fit into a unit of time but does not define the distance between those wavelengths themselves. Thus, understanding wavelength as the distance between crests highlights its essential role in wave properties.