Description: Radio waves are electromagnetic waves that range from a frequency of about
3 hertz and a wavelength on the order of magnitude of 100,000 kilometers to
a frequency of about 300 gigahertz and a wavelength on the order of
magnitude of 1 millimeter. Uses: Radio waves are used by humans for the wireless transmission of sound
messages or other information. Radio waves that originate from outer space
are studied by astronomers to gather information about the universe. Facts: Information is placed in a radio wave in one of three basic ways: Amplitude
modulation (AM), in which the intensity of the wave is varied, frequency
modulation (FM), in which the frequency of the wave is varied, or in
digital form, also known as pulse modulation, in which the signal is
rapidly turned on and off in a defined pattern.
Radio frequencies can be divided into types and uses based on frequency
ranges. For example, VHF (very high frequency) radio waves are used for FM
radio and television, and SLF (super low frequency) waves are used to
communicate with submarines underwater. |
