Béda révisi "Radiasi éléktromagnétik"

 
===Laju rambatan===
Lamun kawat (atawa objék nu boga sifat konduksi saperti [[anteneu]]) ngalirkeun [[arus bulak-balik]] ([[AC]], mangka radiasi éléktromagnétik dirambatkeun dina frékuénsi anu sarua jeung arus listrik kasebut. Gumantung kana kaayaan, radiasi éléktromagnétik bisa nindak salaku [[gelombang]] atawa salaku [[foton|partikel]]. Salaku gelombang, radiasi éléktromagnétik boga ciri mibanda ([[laju cahaya]]), [[panjang gelombang]], jeung [[frékuénsi]]. Waktu dianggap sabagé partikel, radiasi éléktromagnétik dipikawanoh salaku [[foton]], anu boga énergi anu sabanding jeung frékuénsi gelombang sakumaha anu digambarkeun ku rumus [[Max Planck|Planck]] ''E = hν'', dimana ''E'' nyaéta énergi foton, ''h'' = 6.626 &times; 10<sup>-34</sup> J• nyaéta [[konstanta Planck]], sarta ''ν'' nyaéta frékuénsi gelombang.
{{tarjamahkeun|Inggris}}
Any electric charge which accelerates, or any changing magnetic field, produces electromagnetic radiation. Electromagnetic information about the charge travels at the speed of light. Accurate treatment thus incorporates a concept known as [[retarded time]] (as opposed to advanced time, which is unphysical in light of [[causality]]), which adds to the expressions for the electrodynamic [[electric field]] and [[magnetic field]]. These extra terms are responsible for electromagnetic radiation. When any wire (or other conducting object such as an [[antenna (electronics)|antenna]]) conducts [[alternating current]], electromagnetic radiation is propagated at the same frequency as the electric current. Depending on the circumstances, it may behave as a [[wave]] or as [[photon|particle]]s. As a wave, it is characterized by a velocity (the [[speed of light]]), [[wavelength]], and [[frequency]]. When considered as particles, they are known as [[photon]]s, and each has an energy related to the frequency of the wave given by [[Max Planck|Planck's]] relation ''E = hν'', where ''E'' is the energy of the photon, ''h'' = 6.626 &times; 10<sup>-34</sup> J·s is [[Planck's constant]], and ''ν'' is the frequency of the wave.
 
Radiasi éléktromagnétik patuh kana hiji aturan nyaéta, henteu paduli kana lingkunganana, radiasi EM dina rohangan hapa salawasna ngarambat dina laju anu sarua jeung [[laju cahaya]], ''rélatif ka panitén'', henteu paduli kana laju si panitén. (Sifat radiasi éléktromagnétik ieu nungtun [[Albert Einstein]] nyieun téori [[rélativitas husus]].)
One rule is always obeyed regardless of the circumstances: EM radiation in a vacuum always travels at the [[speed of light]], ''relative to the observer'', regardless of the observer's velocity. (This observation led to [[Albert Einstein]]'s development of the theory of [[special relativity]].)
 
In a medium (other than vacuum), [[velocity of propagation]] or [[refractive index]] are considered, depending on frequency and application. Both of these are ratios of the speed in a medium to speed in a vacuum.
 
== Spéktrum éléktromagnétik ==
3.120

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