Béda révisi "Radiasi éléktromagnétik"

m
(Kaca anyar: right|frame|{{Fact|date=June 2007}}Legend<br> γ = [[Gamma rays<br> HX = Hard X-rays<br> SX = Soft X-Rays<br> EUV = Extreme ultraviolet<br> NUV = Near ultr...)
 
m (Mindahkeun ka Gelombang Elektromagnet)
#REDIRECT [[Gelombang Elektromagnet]]
[[Image:spectrum.png|right|frame|{{Fact|date=June 2007}}Legend<br>
γ = [[Gamma ray]]s<br>
HX = Hard [[X-ray]]s<br>
SX = Soft X-Rays<br>
EUV = Extreme [[ultraviolet]]<br>
NUV = Near ultraviolet<br>
[[Visible light]]<br>
NIR = Near [[infrared]]<br>
MIR = Mid infrared<br>
FIR = Far infrared<br>
<br>
[[Radio waves]]<br>
EHF = [[Extremely high frequency]] (Microwaves)<br>
SHF = [[Super high frequency]] (Microwaves)<br>
UHF = [[Ultra high frequency]]<br>
VHF = [[Very high frequency]]<br>
HF = [[High frequency]]<br>
MF = [[Medium frequency]]<br>
LF = [[Low frequency]]<br>
VLF = [[Very low frequency]]<br>
VF = [[Voice frequency]]<br>
ELF = [[Extremely low frequency]]]]
 
'''Gelombang elektromagnetik (EM)''' nyaeta kabeh gelombang anu dihasilkeun tina interaksi antara medan listrik jeung medan magnet. Gelombang EM ngawengku gelombang-gelombang ti mimiti nu panjangna rebuan [[kilometer]] tepi sapondok ukuran [[atom]]. Umumnya disebutkeun yen gelombang EM anu panjangna di luar wates-wate kasebut henteu lumrah, sanajan anggapan ieu henteu sakabehna bener. Batas gelombang pondok kamungkinan ngarupakeun [[gelombang Planck]], jeung wates panjang gelombang pang panjangna saukuran jeung jagat (tingali [[kosmologi fisika]]), sanajan dina dasarna spektrum teh [[taya hinggana|taya hingga]].
 
Enerji elektromagnetik dina sahiji [[panjang gelombang]] [[lambda|λ]] (dina ruang hampa) miboga sahiji [[frekuensi]] ''f'' jeung [[enerji]] [[foton]] ''E''. Jadi, spektrum elektromagnetik bisa dinyatakeun dina tilu kuantitas ieu. Katilu kuantitas ieuc dihubungkeun ku rumus:
 
:''laju gelombang'' (''c'') = ''frekuensi'' x ''panjang gelombang''
 
atawa
 
:<math>\lambda = \frac{c}{f} \,\!</math>
 
jeung
 
:<math>E=hf \,\!</math>
 
atawa
 
:<math>E=\frac{hc}{\lambda} \,\!</math>
 
dimana:
* ''c'' nyaeta [[laju cahaya]], 299,792,458 m/s (pasti).
* ''h'' nyaeta [[konstanta Planck]], <math>(h \kira-kira 6.626069 \cdot 10^{-34} \ \mbox{J} \cdot \mbox{s} \approx 4.13567 \ \mathrm{\mu} \mbox{eV}/\mbox{GHz})</math>.
 
Jadi, gelombang elektromagnet frekuensi luhur miboga panjang gelombang nu pondok jeun enerji anu gede; gelombang elektromagnet frekuensi handap miboga panjang gelombang anu panjang sarta enerji anu saeutik.
 
Mangsa gelombang cahaya (jeung gelombang elektromagnetik lianna) asup kana sahiji mediyeum, [[panjang gelombang]]na ngurangan. Panjang gelombang radiasi elektromagnetik, teu paduli mediyeum naon anu diliwatanna, biasana dirumuskeun dikaitkeun jeung panjang gelombang ruang hampa, sanajan hal ieu teu salawasna dinaytakeun sacara jelas.
 
 
== Spectra of objects ==
[[Image:Electromagnetic-Spectrum.png|right|thumb|250px|Electromagnetic Spectrum Image.]]
Nearly all known objects in the [[universe]] emit, reflect or transmit some light. (One exception, however, may be [[dark matter]], which, along with [[Dark energy]] may make up 96% of the universe's total mass.) The distribution of this light along the electromagnetic spectrum (called the ''spectrum'' of the object) is determined by the object's composition. Several types of spectra can be distinguished depending upon the nature of the radiation coming from an object:
 
* If the spectrum is composed primarily of [[thermal radiation]] emitted by the object itself, an ''[[emission spectrum]]'' occurs.
** Some bodies emit light more or less according to the [[blackbody spectrum]].
* If the spectrum is composed of background light, parts of which the object transmits and parts of which it absorbs, an ''[[absorption spectrum]]'' occurs.
 
[[Electromagnetic spectroscopy]] is the branch of physics that deals with the characterization of matter by its spectra.
[[Image:Incandescent lamp spectra.png|left|thumb|150px|Spectrum of incandescent lamp, in IR range, with b/g noise in yellow]]
A Halogen incandescent lamp, has a light spectra as shown in the accompanying figure. The figure shows just the infrared end of the whole spectra, which is limited by the resolution of the spectrum analyzer from 600 nm to 1500 nm, in the optical window, typical to fiber optic communication systems.
 
 
 
== External links ==
{{commonscat|Electromagnetic spectrum}}
* [http://www.ntia.doc.gov/osmhome/allochrt.html U.S. Frequency Allocation Chart] — Covering the range 3 kHz to 300 GHz (from [[United States Department of Commerce|Department of Commerce]])
* [http://strategis.ic.gc.ca/epic/internet/insmt-gst.nsf/vwapj/spectallocation.pdf/%24FILE/spectallocation.pdf Canadian Table of Frequency Allocations] (from [[Industry Canada]])
* [http://www.ofcom.org.uk/static/archive/ra/topics/spectrum-strat/future/strat02/strategy02app_b.pdf UK frequency allocation table] (from [[Ofcom]], which inherited the [[Radiocommunications Agency]]'s duties, pdf format)
*[http://www.scienceofspectroscopy.info The Science of Spectroscopy] - supported by NASA, includes OpenSpectrum, a Wiki-based learning tool for spectroscopy that anyone can edit
 
==See also==
*[[W_band]]
*[[V_band]]
 
{{EMSpectrum}}
 
<!--Categories-->
[[Category:Electromagnetic spectrum| ]]
[[Category:Waves| ]]
 
<!--Interwiki-->
[[af:Elektromagnetiese spektrum]]
[[ar:طيف]]
[[bg:Електромагнитен спектър]]
[[ca:Espectre electromagnètic]]
[[cs:Elektromagnetické spektrum]]
[[da:Elektromagnetisk spektrum]]
[[de:Elektromagnetisches Spektrum]]
[[es:Espectro electromagnético]]
[[eu:Espektro elektromagnetikoa]]
[[fr:Spectre électromagnétique]]
[[gl:Espectro electromagnético]]
[[id:Spektrum elektromagnetik]]
[[it:Spettro elettromagnetico]]
[[he:ספקטרום אלקטרומגנטי]]
[[ml:വിദ്യുത്കാന്തിക വര്‍ണ്ണരാജി]]
[[ms:Spektrum elektromagnet]]
[[nl:Elektromagnetisch spectrum]]
[[ja:電磁スペクトル]]
[[pl:Widmo elektromagnetyczne]]
[[pt:Espectro eletromagnético]]
[[sk:Elektromagnetické spektrum]]
[[fi:Sähkömagneettinen spektri]]
[[ta:மின்காந்த நிழற்பட்டை]]
[[tr:Elektromanyetik tayf]]
[[zh:電磁波譜]]
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