Measuring the Length of Radio Waves Purpose To investigate the relative wavelengths of electromagnetic waves.
All electromagnetic waves travel at the same velocity in vacuum, the speed of light.
If the waves are traveling through some material like air or glass, they may travel at some other slower speed. In this case the frequency stays the same as it was in vacuum, but the wavelength decreases. The relationship says something very interesting. It says that if the frequency of the wave f gets higher, the wavelength must get shorter, since . This means that the waves used for the FM band are about a hundred times smaller in wavelength than the waves used for the AM band.