Difference between revisions 1698262 and 1698263 on enwikiversity

'''Electromagnetic radiation''' comes in many different types, although the differences between them are quantitative rather than qualitative.  This teaching aid lists the different types that are generally recognised.

Electromagnetic radiation is an Electromagnetic oscillation wave that travels at speed of visible light carries[[Quantum]]'s energy called [[Photon]]

==Electromagnetic oscillation wave==
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There are many bands within these, which are even vaguer and more prone to overlap.  Each band is discussed in more detail below.  The limits given are rough, so exact consistency between wavelength, frequency and photon energy cannot be expected.

==Microwaves==
{{main|Radiation/Microwaves|Microwave radiation|Microwaves}}
'''Microwaves''' in radio telecommunications are the very shortest wavelengths usable for communication.  They have wavelength 1mm to 30cm, or frequency 1-300 GHz.

An important frequency is 1420 MHz (wavelength 21.1cm).  Interstellar hydrogen radiates at this frequency, making it a very useful frequency for radio astronomers.

Microwaves have only fairly recently been regarded as distinct from very short wavelength radio waves.  Their recognition is probably due to the popularity of microwave ovens.  In fact, these ovens typically use frequencies of 300MHz to 1GHz, or wavelengths 30cm to 100cm, frequencies in the lower half of the UHF band hence slightly below the radio telecommunications definition.⏎
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==Infra-reds==
{{main|Radiation/Infra-reds|Infra-red radiation|Infra-reds}}
'''Infra-red''' radiation, the first non-visible electromagnetic radiation to be discovered, was discovered by William Herschel in 1800.

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There are several terms used.

==External links==
[[Category:Physics]]
[[Category:Electromagnetism]]
[[Category:Radiation]]
[[Category:Resources last modified in August 2016]]