Editing Electronic color code (section)

==Resistors==
{{anchor|Resistor code}}
[[Image:Preferred values 05 Pengo.svg|thumb|One decade of the [[E12 series]] (there are twelve preferred values per decade of values) shown with their electronic color codes on [[resistor]]s]]
[[Image:0-ohm.jpg|thumb|A [[Zero-ohm link|0&nbsp;Ω resistor]] (zero ohm), marked with a single black band]]

===Color band system===
To distinguish left from right there is a gap between the C and D bands:
[[Image:Resistor bands.svg|A diagram of a resistor, with four color bands A, B, C, D from left to right]]
[[Image:4-Band Resistor.svg|A diagram of a 2.7&nbsp;MΩ color-coded resistor.]]
{{ordered list
 | list-style-type=upper-alpha
 | The first significant figure of component value (left side)
 | The second significant figure (some precision resistors have a third significant figure, and thus five bands).
 | The decimal multiplier (number of trailing zeroes, or power of 10 multiplier)
 | If present, indicates tolerance of value in percent (no band means 20%)
}}

In the above example, a resistor with bands of red, violet, green, and gold has first digit 2 (red; see table below), second digit 7 (violet), followed by 5 (green) zeroes: {{val|2,700,000|u=ohms}}. Gold signifies that the tolerance is ±5%.

Precision resistors may be marked with a five band system, to include three significant digits, a power of 10 multiplier (number of trailing zeroes, and a tolerance band. An extra-wide first band indicates a wire-wound resistor.<ref name="Westman_1968"/>
[[File:Resistor Color Code.svg|alt=resistor color code|thumb|Resistor color code]]
Resistors manufactured for military use may also include a fifth band which indicates component failure rate ([[Reliability engineering|reliability]]); refer to [[MIL-HDBK]]-199<ref name="MIL_HDBK_199C"/> for further details.

Tight tolerance resistors may have three bands for significant figures rather than two, or an additional band indicating [[temperature coefficient of resistance]] (TCR), in units of [[parts per million|ppm]]/[[Kelvin|K]].

All coded components have at least two value bands and a multiplier; other bands are optional.

The standard color code per [[IEC 60062:2016]] is as follows:
{{Electronic colour code}}
Resistors use various [[E series of preferred numbers#Lists|E series of preferred numbers]] for their specific values, which are determined by their [[tolerance (engineering)|tolerance]]. These values repeat for every decade of magnitude: ... 0.68, 6.8, 68, 680, ... For resistors of 20% tolerance the E6 series, with six values: 10, 15, 22, 33, 47, 68, then 100, 150, ... is used; each value is approximately the previous value multiplied by {{radic|10|6}}. For 10% tolerance resistors the E12 series, with {{radic|10|12}} as multiplier, is used; similar schemes up to E192, for 0.5% or tighter tolerance are used. The separation between the values is related to the tolerance so that adjacent values at the extremes of tolerance approximately just overlap; for example, in the E6 series {{nobr|10 + 20%}} is 12, while {{nobr|15 − 20%}} is also 12.

[[Zero ohm resistor]]s, marked with a single black band,<ref name="NZO_NIC"/> are lengths of wire wrapped in a resistor-like body which can be mounted on a [[printed-circuit board]] (PCB) by automatic component-insertion equipment. They are typically used on PCBs as insulating "bridges" where two tracks would otherwise cross, or as soldered-in [[Jumper (computing)|jumper]] wires for setting configurations.

=== Body-end-dot system ===
The "body-end-dot" or "body-tip-spot" system was used for cylindrical composition resistors sometimes still found in very old equipment (built before the Second World War); the first band was given by the body color, the second band by the color of one end of the resistor, and the multiplier by a dot or band around the middle of the resistor. The other end of the resistor was in the body color, silver, or gold for 20%, 10%, 5% tolerance (tighter tolerances were not routinely used).<ref name="FTRC_1946"/><ref name="BTS"/><ref name="RMA"/><ref name="Antique_Resistor"/>

===Examples===
[[Image:Resistors color code.jpg|right|300px|thumb|Example color-coded resistors]]
From top to bottom:
* Green, blue, black, black, brown
** 560&nbsp;ohms ±1%
* Red, red, orange, gold
** {{val|22000|u=ohms}} ±5%
* Yellow, violet, brown, gold
** 470&nbsp;ohms ±5%
* Blue, grey, black, gold
** 68&nbsp;ohms ±5%

The physical size of a resistor is indicative of the [[power (physics)|power]] it can dissipate.

There is an important difference between the use of three and of four bands to indicate resistance. The same resistance is encoded by:
*Red, red, ''orange'' = ''22'' followed by ''3'' zeroes = {{val|22000}} (excluding default, silver, or gold tolerance)
*Red, red, ''black'', ''red'' = ''220'' followed by ''2'' zeroes = {{val|22000}} (excluding brown or other band for tolerance)

===Mnemonics===
{{Further|List of electronic color code mnemonics}}

Useful [[mnemonic]]s have been created to make it easier to remember the numeric order of resistor color bands:

* '''B'''etty '''B'''rown '''R'''uns '''O'''ver '''Y'''our '''G'''arden '''B'''ut '''V'''iolet '''G'''ingerly '''W'''alks.
* '''B'''ad '''B'''ears '''R'''aid '''O'''ur '''Y'''ummy '''G'''rub '''B'''ut '''V'''eto '''G'''rey '''W'''affles.
* '''BB''' '''ROY''' from '''G'''reat '''B'''ritain has a '''V'''ery '''G'''ood '''W'''ife. 
The following example includes the tolerance codes — gold, silver and none:

* '''B'''ad '''B'''eer '''R'''ots '''O'''ut '''Y'''our '''G'''uts '''B'''ut '''V'''odka '''G'''oes '''W'''ell – '''G'''et '''S'''ome '''N'''ow.<ref name="Campbell_BUCD"/>

The colors are sorted in ascending order of visible light photon [[visible light spectrum|frequency/energy]] like in a rainbow to make them easy to remember and to reduce the significance of possible read errors due to color shifts and fading over time<!-- except for the tolerance ring -->: red (2), orange (3), yellow (4), green (5), blue (6), violet (7). Black (0) has no energy, brown (1) has a little more, white (9) has everything and grey (8) is like white, but less intense.<ref name="Clement"/>