Wavelength and Frequency wavelength Copyright2010 Pearson Prentice Hall,Inc. The frequency of a wave is the number of complete cycles that pass a fixed point in a second. Wavelength is the distance between any two peaks (or any two troughs)of the wave. Chapter 12 4Chapter 12 4 Wavelength and Frequency • The frequency of a wave is the number of complete cycles that pass a fixed point in a second. • Wavelength is the distance between any two peaks (or any two troughs) of the wave