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how the radio radiation happens?
Radio waves are generated by a disturbance of the electromagnetic field.
An EM wave is composed of an electric field and a magnetic field that are oscillating together. The fields are oriented perpendicular to each other, and the wave travels in a direction perpendicular to both of the fields.

Lightning for example gives out a pulse of radio waves over a broad range of frequencies, because of the ionization of the air.

For communication & TV, an electronic oscillator is used to generate an electrical signal, and when fed to an antenna, this signal will generate radio waves. These particular radio waves are modulated to carry the information - speech - pictures etc.


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