What is Resistor?
[[File:6 different resistors.jpg|thumb|right|200px|6 different resistors]] [[File:Serial Resistors.svg|thumb|Two resistors in serial circuit]] [[File:Parallel Resistors.svg|thumb|Two resistors in parallel circuit]] [[File:Tw-resistor-color-code-ex22-ohms.gif|thumb|Resistor color code]] A '''resistor''' limits the [[electric current]] that flows through a circuit. Resistance is the restriction of current.<ref>{{cite book |last=Lowery |first=Lawrence |date=2001 |title=Electronics Resources |url=http://delta-education.com/productdetail.aspx?Collection=N&prodID=4108&return=1096= |location=Berkeley, CA |publisher=Lawrence Hall of Science |page=6-8 |isbn=1583564209 |accessdate=2015-05-12 }}{{Dead link|date=November 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> In a resistor the energy of the [[electron]]s that pass through the resistor are changed to heat and/or light. For example, in a [[light bulb]], the [[tungsten]] filament acts as a resistor that heats up because of the current going through it, causing it to glow.<ref>{{cite web |url=http://www.qrg.northwestern.edu/projects/vss/docs/thermal/3-whats-a-resistor.html|title=what's a resistor|accessdate=20 May 2012}}</ref> == Series and parallel == Resistors can be linked in various combinations to help make a [[electrical circuit|circuit]]: #Series - Where the resistors are linked ''one after another''. #Parallel - Where the resistors are linked ''over one another''. There are many different types of resistors. Resistors have different power ratings to tell engineers how much [[Watt|power]] they can handle before they break and how accurate their value is.<ref>{{cite web |url=http://physics.bu.edu/py106/notes/Circuits.html |title= series and parallel circuits |accessdate=20 May 2012}}</ref> Connecting two resistors in series results in a higher resistance, and connecting them in parallel makes a lower resistance. Nowadays the electrical industry in many cases uses so called [[surface-mount technology]] based resistors which can be very small.<ref na