3 Resistor Color Code Lab Exercise printable pdf download

3 Resistor Color Code Lab Exercise

EXPERIMENT NO. 1

Resistor Color Code

Objective

The objective of this exercise is to become familiar with the measurement of resistance values using a

digital multimeter (DMM). A second objective is to learn the resistor color code.

Theory Overview

The resistor is perhaps the most fundamental of all electrical devices. Its fundamental attribute is the

restriction of electrical current flow: The greater the resistance, the greater the restriction of current.

Resistance is measured in Ohms. The measurement of resistance in unpowered circuits may be performed

with a digital multimeter. Like all components, resistors cannot be manufactured to perfection. That is, there

will always be some variance of the true value of the component when compared to its nameplate or

nominal value. For precision resistors, typically 1% tolerance or better, the nominal value is usually printed

directly on the component. Normally, general purpose components, i.e. those worse than 1%, usually use a

color code to indicate their value.

The resistor color code typically uses 4 color bands. The first two bands indicate the precision values (i.e.

the mantissa) while the third band indicates the power of ten applied (i.e. the number of zeroes to add). The

fourth band indicates the tolerance. It is possible to find resistors with five or six bands but they will not be

examined in this exercise. Examples are shown below:

It is important to note that the physical size of the resistor indicates its power dissipation rating, not its

ohmic value.

Each color in the code represents a numeral. It starts with black and finishes with white, going through the

rainbow in between:

0 Black

1 Brown

2 Red

3 Orange

4 Yellow

5 Green

6 Blue

7 Violet

8 Gray

9 White

For the fourth, or tolerance, band:

5% Gold

10% Silver

20% None

3 Resistor Color Code Lab Exercise