chapter  49
2 Pages

Topic 49. Radio Transmission

If we apply the output from an oscillator to a pair of metal rods, electrons rush to and fro along the rods. Their rapid motion generates an electromagnetic field. Electromagnetic waves spread outward from the rods, like ripples on a pond, only in three dimensions. If the frequency of the oscillator is between 30 Hz and 30 GHz, the waves are radio waves.