केल्विन का स्रोत देखें

{{एक स्रोत}}
{{तापमान}}
'''कैल्विन''' (चिन्ह: '''K''') [[तापमान]] की मापन इकाई है। यह सात [[मूल इकाइयाँ|मूल इकाईयों]] में से एक है। कैल्विन पैमाना ऊष्मगतिकीय तापमान पैमाना है, जहाँ, परिशुद्ध शून्य, पूर्ण ऊर्जा की सैद्धांतिक अनुपस्थिति है, जिसे शून्य कैल्विन भी कहते हैं। (0 K)

कैल्विन पैमाना और कैल्विन के नाम [[यूनाइटेड किंगडम|ब्रिटिश]] भौतिक शास्त्री और अभियाँत्रिक [[:en:William Thomson, 1st Baron Kelvin|विलियम थामसन, प्रथम बैरन कैल्विन]] (1824–1907) के नाम पर रखा गया है, जिन्होंने विशुद्ध तापमानमापक पैमाने की आअवश्यकत जतायी थी।(0 K ≡ −273.15 °C और 273.16 K ≡ 0.01)

== कैल्विन की परिभाषा ==
[[File:CelsiusKelvinThermometer.jpg|thumb|200px|]]
कैल्विन और कैल्विन पैमाना, अन्तर्राष्ट्रीय समझौते के अनुसार दो बिंदुओं द्वारा परिभाषित हैं: [[:en:Vienna Standard Mean Ocean Water|वियना मानक औसत महासागरीय जल]] (VSMOW) के [[विशुद्ध बिंदु]] और [[त्रिगुण बिंदु]].<ref name=sib2115>{{cite web | title=Unit of thermodynamic temperature (kelvin) | work=SI Brochure, 8th edition | pages=Section 2.1.1.5 | url=http://www1.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/kelvin.html | publisher=Bureau International des Poids et Mesures | date=1967 | accessdate=2008-02-06 | archive-url=https://web.archive.org/web/20070926215600/http://www1.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/kelvin.html | archive-date=26 सितंबर 2007 | url-status=dead }}</ref> यह परिभाषा कैल्विन पैमाने को सीधे सेल्सियस पैमाने से जोड़ती है। 
विशुद्ध शून्य: इसे परम शून्य भी कहते हैं। वह तापमान, जिससे अधिक शीतल कुछ भी संभव नहीं होता और वस्तु में कुछ भी ऊर्जा नहीं शेष रहती है। — यह परिभाषा अनुसार 0 K ''और'' −273.15&nbsp;°C है। 
जल का [[त्रिगुण बिंदु]] परिभाषा अनुसार, यथार्थतः 273.16 K ''और'' 0.01&nbsp;°C होता है। इस परिभाषा से तीन कार्य होते है:
# यह कैल्विन इकाई की महत्ता स्थिर करता है, जो कि 273.16 के परम शून्य और जल के त्रिगुण बिंदु के अन्तर का एक भाग होता है;
# यह स्थापित करता है, कि एक कैल्विन की महत्ता यथार्थतः सेल्सियस पैमाने की एक डिग्री बढ़ोत्तरी के बराबर हो; और
# यह दोनों पैमानों के नल बिंदुओं के अन्तर को 273.15 kelvins (0 K ≡ −273.15&nbsp;°C और 273.16 K ≡ 0.01&nbsp;°C) के बराबर रखता है। कैल्विन में तापमान को अन्य पैमानों में निम्न सारणी द्वारा अंतरण किया जासकता है।

=== कैल्विन के तुल्य ===

{| border="1" cellpadding="4" cellspacing="0" style="margin: 1em 1em 1em 0; background: #f5f5f0; border: 2px #52524d solid; border-collapse: collapse; font-size: 95%;"
|-
|style="background:#d4d4d4" align="center"|''' '''
|style="background:#d4d4d4" align="center"|'''कैल्विन'''
|style="background:#d4d4d4" align="center"|'''सेल्सियस'''
|style="background:#d4d4d4" align="center"|'''फ़ैरन्हाइट'''
|-
|style="background:#d9d9d3" align="right"|परम शून्य<br />
(exactly, परिभाषा अनुसार)
|align="center"|0 K
|align="center"|−273.15&nbsp;°C
|align="center"|−459.67&nbsp;°F
|-
|style="background:#d9d9d3" align="right"|जल का हिमांक बिंदु
|align="center"|273.15 K
|align="center"|0&nbsp;°C
|align="center"|32&nbsp;°F
|-
|style="background:#d9d9d3" align="right"|जल का त्रिगुण बिंदु<br />
(exactly, by definition)
|align="center"|273.16 K
|align="center"|0.01&nbsp;°C
|align="center"|32.018&nbsp;°F
|-
|style="background:#d9d9d3" align="right"|जल का [[क्वथनांक]]
|align="center"|373.1339 K
|align="center"|[[सेल्सियस#जल के हिमांक और क्वथानांक|99.9839 °C]]
|align="center"|211.9710&nbsp;°F
|}

<!-- For [[Vienna Standard Mean Ocean Water]] (VSMOW) at one [[Atmosphere (unit)|standard atmosphere]] (101.325 kPa) when calibrated solely per the two-point definition of thermodynamic temperature. Older definitions of the Celsius scale once defined the boiling point of water under one standard atmosphere as being exactly 100 °C. However, the current definition results in a boiling point that is actually 16.1 mK less. For more about the actual boiling point of water, see [[Vienna Standard Mean Ocean Water#VSMOW in temperature measurement|VSMOW in temperature measurement]]. -->

=== SI उपसर्ग === <!-- This section is linked from [[Absolute zero]], [[Thermodynamic temperature]], as well as from other articles. Only delete or rename it with careful consideration, and please fix any resulting broken links.-->

{{SI गुणक|unit=केल्विन|symbol=K}}

<!-- == Typographical and usage conventions ==
===Uppercase/lowercase, plural form usage, and written conventions===
When reference is made to the unit kelvin (either a specific temperature or a temperature interval), kelvin is always spelled with a lowercase k unless it is the first word in a sentence.<ref>BIPM: SI brochure, [http://www1.bipm.org/en/si/si_brochure/chapter5/5-2.html Section&nbsp;5.2]</ref> When reference is made to the "Kelvin ''scale''", the word "kelvin"—which is normally a noun—functions [[adjective|adjectivally]] to modify the noun "scale" and is capitalized.

Until the 13th [[General Conference on Weights and Measures]] (CGPM) in 1967–1968, the unit kelvin was called a "degree", the same as with the other temperature scales at the time. It was distinguished from the other scales with either the adjective suffix "Kelvin" ("degree Kelvin") or with "absolute" ("degree absolute") and its symbol was °K. Note that the latter (degree absolute), which was the unit’s official name from 1948 until 1954, was rather ambiguous since it could also be interpreted as referring to the [[Rankine scale]]. Before the 13th CGPM, the plural forms were "degrees Kelvin" or "degrees absolute". The 13th CGPM changed the name to simply "kelvin" (symbol K).<ref>{{cite paper | author=Barry N. Taylor | title=Guide for the Use of the International System of Units (SI) | version=Special Publication 811 | format=.PDF | publisher=National Institute of Standards and Technology | url=http://physics.nist.gov/cuu/pdf/sp811.pdf | date=1995 | accessdate=2008-02-06}}</ref> The omission of "degree" indicates that it is not relative to an arbitrary reference point such as the Celsius and Fahrenheit scales, but rather an absolute unit of measure which can be manipulated algebraically (e.g. multiply by two to indicate twice the amount of heat). -->

=== तापमान और अंतराल ===
<!-- Because the kelvin is an individual unit of measure, it is particularly well-suited for expressing ''temperature intervals:'' differences between temperatures or their uncertainties (e.g., “Agar exhibited a melting point hysteresis of 25 kelvins.” and “The uncertainty was 10 millikelvins.”). Of course, the kelvin is also used to express specific temperatures along its scale (e.g. “[[Gallium]] melts at 302.9146 kelvin”).

One disadvantage of the kelvin is that intervals ''and'' specific temperatures on the Kelvin scale use exactly the same symbol (e.g., “Agar exhibited a melting point hysteresis of 25 K,” and “The triple point of hydrogen is 13.8033 K”). -->

<!-- ===Formatting and typestyle for the K symbol===
The kelvin symbol is always a [[Roman type|roman]], [[Italic type|non-italic]] capital K. In the SI naming convention, all symbols named after a person are capitalized; in the case of the kelvin, capitalizing also distinguishes the symbol from the SI prefix “kilo”, which has the lowercase k as its symbol. The admonition against italicizing the symbol K applies to all SI unit symbols; only symbols for variables and constants (e.g. ''P'' = pressure, and ''c'' = 299,792,458 m/s) are italicized in scientific and engineering papers. As with most other SI unit symbols (angle symbols, e.g. 45° 3′ 4″, are the exception) there is a space between the numeric value and the kelvin symbol (e.g. “99.987 K”).<ref name=nist>{{cite web | title=SI Unit rules and style conventions | url=http://physics.nist.gov/cuu/Units/checklist.html | publisher=National Institute of Standards and Technology | date=September 2004 | accessdate=2008-02-06}}</ref><ref name=sib533>{{cite web | title=Rules and style conventions for expressing values of quantities | work=SI Brochure, 8th edition | pages=Section 5.3.3 | url=http://www.bipm.org/en/si/si_brochure/chapter5/5-3-2.html#5-3-3 | publisher=Bureau International des Poids et Mesures | date=1967 | accessdate=2008-02-06}}</ref>

===The special Unicode kelvin character===
[[Unicode]] provides a [[Unicode compatibility characters|compatibility character]] for the kelvin at U+212A (decimal 8490), for compatibility with CJK encodings that provide such a character (as such, in most fonts the width is the same as for [[fullwidth]] characters). Below in maroon text is the kelvin character followed immediately by a simple uppercase K:

:<span class="Unicode" style="color:#721F01;font-size:bigger">K K</span>

When viewed on computers that properly support Unicode, the above line may be similar to the line below (size may vary): -->

:[[चित्र:Kelvin symbol plus K.svg|23px]]
<!-- 
The canonical decomposition of this character is U+004B (uppercase K), so some browsers may simply display a "K" in its place due to [[Unicode normalization]].-->

=== कैल्विन और सेल्सियस पैमानों का तकनीकी लेखों में मिश्रित प्रयोग ===
<!-- In science and in engineering, the Celsius scale and the kelvin are often used simultaneously in the same article (e.g. “…its measured value was 0.01023 °C with an uncertainty of 70 µK…”). This practice is permissible because the degree Celsius is a special name for the kelvin for use in expressing Celsius temperatures and the magnitude of the degree Celsius is exactly equal to that of the kelvin.<ref name=sib222>{{cite web | title=Units with special names and symbols; units that incorporate special names and symbols | work=SI Brochure, 8th edition | pages=Section 2.2.2, Table 3 | url=http://www.bipm.org/en/si/si_brochure/chapter2/2-2/table3.html | publisher=Bureau International des Poids et Mesures | date=2006 | accessdate=2008-02-06}}</ref> Notwithstanding the official endorsement provided by Resolution 3 of the 13th CGPM, states “a temperature interval may also be expressed in degrees Celsius,” the practice of simultaneously using both “°C” and “K” remains widespread throughout the scientific world as the use of [[SI prefix#List of SI prefixes|SI prefixed]] forms of the degree Celsius (such as “µ°C” or “microdegrees Celsius”) to express a temperature interval has not been well-adopted.<ref name=res313>{{cite web | title=Resolution 3: SI unit of thermodynamic temperature (kelvin) | work=Resolutions of the 13th CGPM | url=http://www.bipm.fr/en/CGPM/db/13/3/ | publisher=Bureau International des Poids et Mesures | date=1967 | accessdate=2008-02-06}}</ref> -->

== वर्ण तापमान ==
 <!-- The kelvin is often used in the measure of the [[color temperature]]of light sources. Color temperature is based upon the principle that a [[black body|black body radiator]] emits light whose color depends on the temperature of the radiator. Black bodies with temperatures below about 4000 K appear reddish whereas those above about 7500 K appear bluish. Color temperature is important in the fields of image projection and [[photography]] where a color temperature of approximately 5500 K is required to match “daylight” film emulsions. In [[astronomy]], the [[stellar classification]] of stars and their place on the [[Hertzsprung-Russell diagram]] are based, in part, upon their surface temperature, known as [[effective temperature]]. The photosphere of the Sun, for instance, has an effective temperature of 5777 K. -->

== कैल्विन पैमाने का इतिहास ==
<!-- Below are some historic milestones in the development of the Kelvin scale and its unit increment, the kelvin. For more on the history of thermodynamic temperature, see ''Thermodynamic temperature: [[Thermodynamic temperature#History of thermodynamic temperature|History of thermodynamic temperature]].''

* '''1848:''' [[William Thomson, 1st Baron Kelvin|Lord Kelvin (William Thomson)]], wrote in his paper, ''On an Absolute Thermometric Scale,'' of the need for a scale whereby “infinite cold” (absolute zero) was the scale’s null point, and which used the degree Celsius for its unit increment. Thomson calculated that absolute zero was equivalent to −273 °C on the air thermometers of the time.<ref name=lordkelvin>{{cite journal | last=Thomson | first=William | coauthors= | title=On an Absolute Thermometric Scale | journal=Philosophical Magazine | month=October | year=1848 | url=http://zapatopi.net/kelvin/papers/on_an_absolute_thermometric_scale.html | accessdate=2008-02-06}}</ref> This absolute scale is known today as the Kelvin thermodynamic temperature scale. It’s noteworthy that Thomson’s value of “−273” was actually derived from 0.00366, which was the accepted expansion coefficient of gas per degree Celsius relative to the ice point. The inverse of −0.00366 expressed to five significant digits is −273.22 °C which is remarkably close to the true value of −273.15 °C.

* '''1954:''' Resolution 3 of the 10th CGPM gave the Kelvin scale its modern definition by designating the triple point of water as its second defining point and assigned its temperature to exactly “273.16 degrees Kelvin.”<ref name=res310>{{cite web | title=Resolution 3: Definition of the thermodynamic temperature scale | work=Resolutions of the 10th CGPM | publisher=Bureau International des Poids et Mesures | url=http://www.bipm.fr/en/CGPM/db/10/3/ | date=1954 | accessdate=2008-02-06}}</ref>

* '''1967/1968:''' Resolution 3 of the 13th CGPM renamed the unit increment of thermodynamic temperature “kelvin”, symbol K, replacing “degree absolute”, symbol °K.<ref name=res313/> Further, feeling it useful to more explicitly define the magnitude of the unit increment, the 13th CGPM also held in Resolution 4 that “The kelvin, unit of thermodynamic temperature, is equal to the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.”<ref name=res413>{{cite web | title=Resolution 4: Definition of the SI unit of thermodynamic temperature (kelvin) | work=Resolutions of the 13th CGPM | url=http://www.bipm.fr/en/CGPM/db/13/4/ | publisher=Bureau International des Poids et Mesures | date=1967 | accessdate=2008-02-06}}</ref>

* '''2005:''' [[International Committee for Weights and Measures|The Comité International des Poids et Mesures]] (CIPM), a committee of the CGPM, affirmed that for the purposes of delineating the temperature of the triple point of water, the definition of the Kelvin thermodynamic temperature scale would refer to water having an isotopic composition specified as ''[[Vienna Standard Mean Ocean Water|VSMOW]]''.<ref name=sib2115/> -->

== इन्हें भी देखेदे ==
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* [[ऊष्मागतिक तापक्रम|ऊष्मगतिकीय तापमान]]
== सन्दर्भ ==
{{reflist|2}}

== बाहरी कड़ियां ==
{{विक्षनरी}}
* {{cite paper | author=Bureau International des Poids et Mesures | title=The International System of Units (SI) Brochure | version=8th Edition | format=.PDF | publisher=International Committee for Weights and Measures | url=http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf | date=2006 | accessdate=2008-02-06}}

{{TemperatureScales}}
{{अन्तर्राष्ट्रीय इकाई प्रणाली}}

[[श्रेणी:SI मूल इकाइयाँ]]
[[श्रेणी:तापमान की इकाइयँ]]
[[श्रेणी:भौतिकी]]