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arc
arc in electricity, highly luminous and intensely hot discharge of electricity between two electrodes. The arc was discovered early in the 19th cent. by the English scientist Sir Humphry Davy, who so named it because of its shape. An arc is characterized by a high current, low voltage, and indefinite duration. It is usually started when two electrodes carrying an electric current are drawn apart. At the instant the electrodes are parted, strong electric forces draw electrons from one electrode to the other, initiating the arc. The discharge consists of a current composed of these electrons and charged gas particles, called ions, that form between the electrodes. The first practical electric light, the arc lamp, made use of the arc formed between two carbon rods (see lighting ). Today the use of the arc lamp is limited to special purposes, e.g., in searchlights and in research applications. The principle of the electric arc is employed in welding (as in the hydrogen arc, where hydrogen is introduced between tungsten electrodes) and also in generating heat in the electric furnace. A spark, like an arc, is a discharge of electricity between two points, but it has a high voltage and a short duration. Lightning is an example of a spark. |
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"arc." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "arc." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1E1-arc-elec.html "arc." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-arc-elec.html |
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arc
arc / ärk/ • n. 1. a part of the circumference of a circle or other curve. ∎ a curved shape, or something shaped like a curve: the arc of the sky. ∎ a curving trajectory: he swung his flashlight in an arc. ∎ [as adj.] Math. indicating the inverse of a trigonometrical function. 2. (also electric arc) a luminous electrical discharge between two electrodes or other points. • v. (arced ; arc·ing ) [intr.] 1. move with a curving trajectory: the ball arced across the room. 2. [usu. as n.] (arcing) form an electric arc: check that switches operate properly with no sign of arcing. PHRASES: minute of arcsee minute1 (sense 2). second of arcsee second2 (sense 2). |
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"arc." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "arc." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O999-arc005.html "arc." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-arc005.html |
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arc
arc in geometry, a curved line or any part of it; in particular, a portion of the circumference of a circle. The length s of an arc of a circle of radius r and subtending a central angle of θ radians is s = r θ; if θ is measured in degrees, then the arc is given by s =2π r θ/360. |
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Cite this article
"arc." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "arc." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1E1-arc-geo.html "arc." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-arc-geo.html |
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arc
arc Portion of a curve. For a circle, the length (s) of an arc is found either by 2rπ × θ/360 or the product of the radius (r) and the angle (θ), measured in radians, that it subtends at the centre: that is, s = r θ.
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"arc." World Encyclopedia. 2005. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "arc." World Encyclopedia. 2005. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O142-arc.html "arc." World Encyclopedia. 2005. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-arc.html |
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ARC
ARC / ärk/ • abbr. ∎ Med. AIDS-related complex. ∎ American Red Cross. |
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Cite this article
"ARC." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "ARC." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O999-arc.html "ARC." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-arc.html |
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arc
arc A part of a circle. Angular measure is given in units of arc. See Degree of Arc; Minute of Arc; Second of Arc; Radian.
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"arc." A Dictionary of Astronomy. 1997. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "arc." A Dictionary of Astronomy. 1997. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O80-arc.html "arc." A Dictionary of Astronomy. 1997. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-arc.html |
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arc
arc XIV. — (O)F. :- L. arcus bow, arch.
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T. F. HOAD. "arc." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. T. F. HOAD. "arc." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O27-arc.html T. F. HOAD. "arc." The Concise Oxford Dictionary of English Etymology. 1996. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O27-arc.html |
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ARC
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"ARC." A Dictionary of Nursing. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "ARC." A Dictionary of Nursing. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O62-ARC.html "ARC." A Dictionary of Nursing. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-ARC.html |
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arc
arc of a graph. See graph.
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JOHN DAINTITH. "arc." A Dictionary of Computing. 2004. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. JOHN DAINTITH. "arc." A Dictionary of Computing. 2004. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O11-arc.html JOHN DAINTITH. "arc." A Dictionary of Computing. 2004. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O11-arc.html |
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arc
arc See ISLAND ARC.
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AILSA ALLABY and MICHAEL ALLABY. "arc." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "arc." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O13-arc.html AILSA ALLABY and MICHAEL ALLABY. "arc." A Dictionary of Earth Sciences. 1999. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-arc.html |
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arc
arc
•arc, ark, Bach, bark, barque, Braque, Clark, clerk, dark, embark, hark, impark, Iraq, Ladakh, Lamarck, lark, macaque, marc, mark, marque, narc, nark, Newark, park, quark, sark, shark, snark, spark, stark, Vlach
•matriarch, patriarch
•tanbark • ringbark • stringy-bark
•Offenbach • ironbark • oligarch
•salesclerk • titlark • skylark
•meadowlark • woodlark • mudlark
•landmark • checkmark • Denmark
•benchmark • waymark • trademark
•seamark • Bismarck • telemark
•tidemark • Kitemark • pockmark
•Ostmark • hallmark • Goldmark
•Deutschmark • bookmark • footmark
•earmark • watermark • birthmark
•anarch • car park • skatepark
•ballpark
•Petrarch, tetrarch
•hierarch, squirearch
•exarch • Pesach • loan shark
•Plutarch • aardvark
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"arc." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "arc." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O233-arc.html "arc." Oxford Dictionary of Rhymes. 2007. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-arc.html |
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