YOUR ANSWER:
1. c is correct. Ohms and watts determine the rating of a resistor.
2. b is correct. Resistor "B" is much larger than resistor "A" and physical size is the
main determining factor when considering power ratings.
You can find the resistance of any resistor by using an ohmmeter, but it is easier to find the value of a
resistor by its markings.
Many carbon (axial-lead) resistors have their values printed on them, but they are often mounted so that
you cannot read the printed marking. Also, heat often discolors the resistor body, making it impossible to read.
Some axial-lead resistors are so small that the printed marking cannot be read. To make the value of axial-lead
resistors easy to read, a 12-color marking system has been established and used.
Axial-lead resistors are coded by the end-to-center band system of marking, as shown in drawing below.
In the color-code system of marking, three colors are used to indicate the resistance value in ohms, and a
fourth color is used to indicate the tolerance of the resistor. By reading the colors in the correct order and
substituting the corresponding numbers from the code chart, you can immediately tell all you need to know about
the resistor.
Select the statement below that describes how to find the resistance of an axial-lead resistor. Circle your
choice.
a. To find the resistance of an axial-lead resistor, a voltmeter is used.
b. To find the resistance of an axial-lead resistor, an end-to-center color band system of marking is used.
(Continued Page 1-27)
IT0340
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