Name: Superconductivity: An Overview
Uploaded: 2019-07-19
Duration: 2 min 51 s
Description: Resistance of mercury at very low temperatures reduces to nearly zero. Certain materials exhibit this property of superconductivity. Let's learn more.

Question

Explain the colour code for carbon resistors with illustrations.

Accepted Answer

There are many types of resistors, both fixed and variable. The most common type for electronics use is the carbon resistor. They are made in different physical sizes with power dissipation limits commonly from 1 watt down to 1/8 watt. The resistance value and tolerance can be determined from the standard resistor colour code.
Resistor Colour Code
Resistance value,
First three bands.
1st band - 1st digit
2nd band - 2nd digit
3rd band - number of zeros.
0 Black
1 Brown
2 Red
3 Orange
4 Yellow
5 Green
6 Blue
7 Violet
8 Gray
9 White
4th band,
Tolerance 5% Gold
10% Silver
20% No band A variation on the colour code is used for precision resistors which may have five coloured bands. In that case the first three bands indicate the first three digits of the resistance value and the fourth band indicates the number of zeros. In the five-band code the fifth band is gold for 1% resistors and silver for 2%.
There is another scheme for resistors which have the values stamped on them. Since a decimal point is easy to miss, this code uses R instead of a decimal point. For values over 100Ωfour numbers are used. The tolerance is indicated by a letter.

Explain the colour code for carbon resistors with illustrations.

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