RADIOWAVES:- Radio is the wireless transmission of signals through free space by electromagnetic radiation with frequency significantly below that of visible light, in the radio frequency range, from about 30 KHz to 300 GHz. These waves are called radio waves. Electromagnetic radiation travels by means of oscillating electromagnetic field that passes through the air and the vacuum of space. Transducing information such as sound into an electronic signal, this is then sent as an electromagnetic radio wave from a transmitter. A receiver intercepts the radio wave and extracts the information-bearing electronic signal, which is converted back using another transducer such as a speaker. Information, for example sound, is carried by systematically changing (modulating) some property of the radiated waves, such as their amplitude, frequency phase or pulse width. When radio waves strike an electrical conducto...
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