Lesson Plan
Course Title
Electronics
Session Title
Resistance (Resistors): Understanding Color Codes
Performance Objective
Upon completion of this assignment, the students will be able to explain resistance and
tolerance. Students will also show they are able to interpret the resistor color codes to
determine the resistance and tolerance of a given resistor by completing the Resistance Value
and Tolerance Range handout and the Resistors Exam.
Specific Objectives
 Define resistance
 Interpret resistor color codes
 Demonstrate how to use the color code chart for resistors
 Read the value and tolerance of a resistor using the color code chart
 Explain tolerance
 List the factors affecting resistance
 Apply Ohm's Law
 Analyze the relationship between resistance, voltage, and current
Preparation
TEKS Correlations
This lesson, as published, correlates to the following TEKS. Any changes/alterations to the
activities may result in the elimination of any or all of the TEKS listed.
Electronics
 130.368 (c)
o (5) The student implements the concepts and skills that form the technical
knowledge of electronics using project-based assessments. The student is
expected to:
(C) demonstrate knowledge of the fundamentals of electronics theory;
(D) perform electrical-electronic troubleshooting assignments; and
(E) develop knowledge of voltage regulation devices.
Interdisciplinary Correlations
Copyright © Texas Education Agency, 2013. All rights reserved.
1
English Language Arts and Reading, English I
 110.31 (b)
o (1) Reading/Vocabulary Development. Students understand new vocabulary and use it
when reading and writing. Students are expected to:
(A) determine the meaning of grade-level technical academic English words in
multiple content areas (e.g., science, mathematics, social studies, the arts)
derived from Latin, Greek, or other linguistic roots and affixes;
(B) analyze textual context (within a sentence and in larger sections of text) to
distinguish between the denotative and connotative meanings of words; and
(E) use a dictionary, a glossary, or a thesaurus (printed or electronic) to
determine or confirm the meanings of words and phrases, including their
connotations and denotations, and their etymology.

110.31 (b)
o (11) Reading/Comprehension of Informational Text/Procedural Texts. Students
understand how to glean and use information in procedural texts and documents.
Students are expected to:
(A) analyze the clarity of the objective(s) of procedural text (e.g., consider
reading instructions for software, warranties, consumer publications); and
(B) analyze factual, quantitative, or technical data presented in multiple
graphical sources.
Occupational Correlation (O*Net –www.onetonline.org)
Job Title: Solderers and Brazers
O*Net Number: 51-4121.07
Reported Job Titles: Brazer, Solderer, Electronic Assembler, Wirer, Assembly Line Brazer,
Connector, Electronic Technician, Fabricator, Production Technician, Electrical Assembler
Tasks







Melt and apply solder along adjoining edges of workpieces to solder joints, using
soldering irons, gas torches, or electric-ultrasonic equipment.
Heat soldering irons or workpieces to specified temperatures for soldering, using gas
flames or electric current.
Examine seams for defects and rework defective joints or broken parts.
Melt and separate brazed or soldered joints to remove and straighten damaged or
misaligned components, using hand torches, irons, or furnaces.
Melt and apply solder to fill holes, indentations, or seams of fabricated metal products,
using soldering equipment.
Clean workpieces to remove dirt or excess acid, using chemical solutions, files, wire
brushes, or grinders.
Guide torches and rods along joints of workpieces to heat them to brazing temperature,
Copyright © Texas Education Agency, 2013. All rights reserved.
2



melt braze alloys, and bond workpieces together.
Adjust electric current and timing cycles of resistance welding machines to heat metals
to bonding temperature.
Clean equipment parts, such as tips of soldering irons, using chemical solutions or
cleaning compounds.
Turn valves to start flow of gases and light flames and adjust valves to obtain desired
colors and sizes of flames.
Soft Skills
 Monitoring
 Quality Control Analysis
 Active Listening
 Critical Thinking
 Operation Monitoring
References
 Dale, C. (1995). Basic electricity and DC circuits. Appendix 4. Interpreting the resistor
color code. Indianapolis, IN: Prompt Publications.
 Gerrish, H. and Dugger, W. and Roberts, R. (1999) Electricity and electronics introduction
to basic electrical circuit materials. Tinley Park, IL: Goodheart-Willcox Company Inc.
 Wikipedia: http://en.wikipedia.org/wiki/Resistor_color_code
Instructional Aids
 Resistance: Using the Resistor Color Code slide presentation and notes
 Resistors Color Code handout
 Resistance Value and Tolerance Range handout
 Resistance Value and Tolerance Range Answer Key
 Resistors Color Code Activity handout
 Resistors Color Code Activity Answer Key
 Resistors Exam
 Resistors Exam Key
Materials Needed
Assortment of different values of resistors and breadboards (one per student).
 Multimeter and leads
 Resistor 470W
 Resistor 1.0KW
 Resistor 1.5KW
 Resistor 1.0MW
 Breadboard
Copyright © Texas Education Agency, 2013. All rights reserved.
3


Breadboard wire pack (pre-trimmed wires for making connections on the breadboard)
6V battery pack (includes 4 – “AA” batteries)
Equipment Needed
 Computer and projection unit
 Color printer for handouts and quiz
Learner Preparation
The student should be able to see different shades of colors.
Introduction
Introduction (LSI Quadrant I)
 Ask
o What does the word resistance mean?
 Say
o Resistance is the opposition to current flow. The symbol is the letter R, and the unit is
measured in ohms (symbol ).
 Ask
o What is a resistor?
 Say
o The resistor is used to create desirable voltage drops and limit current values in
electronic circuitry.
Outline
Teachers can use the slide presentation, slide notes, and handouts in conjunction with the
following outline.
Outline (LSI Quadrant II)
I.
Basic Definitions
A.
Resistors are components used in electronic
equipment.
B.
They resist or limit the flow of current.
C.
The common carbon composition resistors are
all brown with wire leads coming out of each
end.
D.
On the outside they all look alike. Inside they
may be 10 ohms or 10 mega ohms.
Teacher Notes
Begin Resistance: Using the
Resistor Color Code slide
presentation. Use slide notes
to assist with the
presentation.
Slides 2-3
Copyright © Texas Education Agency, 2013. All rights reserved.
4
E.
F.
The color bands on the outside tell the value on
the inside.
Resistors are a linear device.
II.
Resistor Types Overview
A.
The two basic types of resistors are fixed and
variable.
B.
Fixed resistor values are nearly constant, or
constant within a defined tolerance range.
C.
When actual resistance value is outside the
tolerance range, the resistor is “bad” and needs
to be replaced.
D.
Variable resistors are designed to have an
adjustable value.
E.
The adjustment varies the controlled value of
voltage or current, similar to a volume control.
III.
Symbols and Characteristics
Slides 5-9
A.
A fixed resistor has a zigzag line symbol.
B.
A variable resistor has an arrow through (or
pointing toward) the zigzag line.
C.
Note that a real resistor looks like a tube or a
cylinder.
D.
See slides 7 and 8 for pictures and examples of
actual resistors.
E.
Note that the size of the resistor has nothing to
do with resistance value. This subject will be
discussed in more detail later in the
presentation.
F.
Resistance itself is represented by the letter R,
but the unit of resistance has its own name, Ohm
(symbol is Ω).
IV.
Resistor Color Code Chart
A.
Resistors typically come in a standard package
that looks like a tube or a cylinder, with leads
sticking out each end.
B.
An internal mixture of carbon and filler
determines the actual resistance amount, but
you cannot tell the resistance value from the size
or shape of the package itself.
Slide 4
Slides 10-13
Copyright © Texas Education Agency, 2013. All rights reserved.
5
C.
D.
E.
F.
G.
H.
Color bands that encircle the entire resistor
package indicate the resistance.
The bands can be read regardless of the way the
resistor is placed in the circuit.
Each color represents a number.
The placement of the bands indicate whether
the number is part of the numerical value, or a
multiplier, or a tolerance.
Students need to know this resistor color code;
the easiest way to memorize it is to use a
mnemonic aid.
Wikipedia also has a good color code chart and
description:
http://en.wikipedia.org/wiki/Resistor_color_cod
e
V.
Identifying and Reading the Color Bands
Slides 14-30
A.
Notice the color bands are not in the center of
the resistor.
B.
There are two common methods used to identify
the first band.
C.
The first method is to have a small gap between
bands.
D.
The other method is to have the bands start
close to one end of the resistor.
E.
The band closest to the end is band one.
F.
The value is read from a group of bands (typically
three bands); then after the small gap is the
single tolerance band.
G.
Resistor manufacturers will use one method or
the other (but not both).
H.
On some resistors there is a fifth band. This band
can be another value band for a more accurate
resistance value or an indication of the failure
rate (required for military use).
VI.
Understanding Resistor Color Codes
A.
The only way to learn the color code is to
practice reading them from examples.
B.
Start with examples in the presentation, but also
have students look at pictures of real resistors.
C.
The best practice is to have a variety of real
Slides 31-37
Distribute the Resistors Color
Code handout and have
students work in pairs to
complete.
Copyright © Texas Education Agency, 2013. All rights reserved.
6
D.
E.
resistors students can see and touch.
Students have to be able to identify the first
color band, and then apply the resistor color
code to determine resistor value.
Pictures can be shown reversed. This is why we
use pictures and not words to have students
practice applying the color code.
VII.
Resistor Tolerance
A.
Resistor tolerance has been mentioned several
times in this lesson because it is an important
concept that is also confusing.
B.
Tolerance is the range of values a resistor may
have and still be a good resistor.
C.
A resistor marked 100,000 ohms with a tolerance
of 20 percent can vary from that value by 20,000
ohms. (100,000 x 0.2) With an ohm meter, the
resistor measuring between 80,000 ohms and
120,000 ohms is still good.
D.
Tolerance is one reason the ohmmeter measures
resistance other than what is marked on the
resistor. The tighter the tolerance, the closer the
resistor is to the value marked on the resistor.
VIII.
Resistor Measurement
Slides 40-45
A. Actual resistance value of a resistor must be
measured with a multimeter (or ohmmeter).
B. The measured value is often different from the
indicated value (the indicated value is from the
color code).
C. As long as the measured value is within the
tolerance range of the resistor, the resistor is still
good.
D. Students should practice measuring resistance
values not only to see how resistance values can
differ from indicated value but also to gain
experience with using a meter.
E. Print or have students create a chart similar to
the one on slide 43 to compare actual
measurement to indicated value using whatever
resistors you have on hand.
Slides 38-39
Distribute the Resistance
Value and Tolerance Range
handout and have students
complete the handout before
moving to resistor
measurement.
Copyright © Texas Education Agency, 2013. All rights reserved.
7
IX.
Resistor Size vs. Resistor Resistance Value
A.
Resistance value depends on the amount of
carbon mixed in with filler when the resistor is
manufactured.
B.
The carbon mixture values do not affect the size
or shape of the resistor.
C.
Heat is generated in the resistor as it consumes
power in the process of restricting or limiting
current.
D.
The more power a device consumes, the hotter it
gets.
E.
At some point, as the temperature rises, the
device will burn up.
F.
A larger surface area means the device will give
off more heat, meaning it will stay cooler for a
given amount of heat.
G.
This heat formula can be used for a variety of
calculations at the teacher’s discretion, but is
used here only to illustrate the relationship
between heat and temperature. (Doing these
calculations is beyond the scope of this
presentation.)
H.
Have students take the Resistors Exam
Slides 46-52
Distribute and have students
take the Resistors Exam.
Grade exam using answer
key.
X.
Team Challenge
A.
The team challenge involves building a circuit
using resistors on a breadboard and then
measuring electrical values.
B.
This can be an extension/enrichment activity
depending on the lab supplies available.
Slides 53-59
Application
Guided Practice (LSI Quadrant III)
 The teacher will use the notes and handouts to explain the resistor color code. The
student will observe, ask questions, and analyze the teacher’s demonstration.
 The students will review the color code handouts and clarify any questions with the
teacher.
 Students will follow the information given in the slide presentation (Slides 5-21).
Independent Practice (LSI Quadrant III)
Copyright © Texas Education Agency, 2013. All rights reserved.
8




Students will memorize the color codes.
Students will work in pairs doing the Resistors Color Code Activity handout and will use it
to refer to.
Students will complete the Resistance Value and Tolerance Range handout.
Students will take the Resistors Exam.
Summary
Review (LSI Quadrants I and IV)








Question
o What does the word resistance mean?
Answer
o Resistance is the opposition to current flow.
Question
o What is a Resistor?
Answer
o Resistors are components used in electronic equipment. They resist or limit the flow of
current. The resistor is used to create desirable voltage drops and limit current values in
electronic circuitry.
Question
o How do you read a resistor?
Answer
o Hold the resistor in your hand with the band closest to the end of the resistor to your
left. Use the color chart to convert the band colors to get the resistor values, multipliers,
and tolerance.
Question
o How do you measure the ohm value?
Answer
o You measure ohm value with a multimeter.
Evaluation
Informal Assessment (LSI Quadrant III)
Teacher monitors individual/group progress as students work on the guided and independent
practice. Teacher provides individual help/redirection as needed.
Evaluation
Copyright © Texas Education Agency, 2013. All rights reserved.
9
Formal Assessment (LSI Quadrant III, IV)
 Resistor Exam
 Resistor Exam Answer Key
Extension/Enrichment (LSI Quadrant IV):
Students that have mastered the lab assignment, can peer-tutor (one-on-one) any students that
are having difficulty understanding the concept of resistor color code.
Copyright © Texas Education Agency, 2013. All rights reserved.
10
Resistors Color Code
1st Color Band: First digit of value
2nd Color Band: Second digit of value
Tolerance
3 Color Band: Multiplier or numbers of zeros
rd
Example:
Brown
1
Black
0
Yellow
0000
Gold
5%
100,000 ohms = 100k 5%
Significant Digit
First and second band
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White

0
1
2
3
4
5
6
7
8
9
Decimal Multiplier
Third band
1
10
100
1,000 (k)
10,000
100,000
1,000,000 (M)
10,000,000
100,000,000
1,000,000,000
th
Tolerance (4 band): No Band-20%, Silver-10%, Gold-5%
Copyright © Texas Education Agency, 2013. All rights reserved.
11
Name ____________________________________________Date __________________Class ______
Resistance Value and Tolerance Range
Determine the resistance value and tolerance range of the following resistors.
1. A) Indicated resistance:
1.
B) Tolerance:
C) Acceptable resistance value range:
2. A) Indicated resistance:
B) Tolerance:
2.
C) Acceptable resistance value range:
3.
3. A) Indicated resistance:
4.
4. A) Indicated resistance:
5.
5. A) Indicated resistance:
6.
6. A) Indicated resistance:
B) Tolerance:
C) Acceptable resistance value range:
B) Tolerance:
C) Acceptable resistance value range:
B) Tolerance:
C) Acceptable resistance value range:
B) Tolerance:
C) Acceptable resistance value range:
7. A) Indicated resistance:
B) Tolerance:
7.
C) Acceptable resistance value range:
8.
8. A) Indicated resistance:
B) Tolerance:
C) Acceptable resistance value range:
9. A) Indicated resistance:
B) Tolerance:
9.
C) Acceptable resistance value range:
10.
10. A) Indicated resistance:
B) Tolerance:
C) Acceptable resistance value range:
11.
How would you tell a 1 W resistor from a ½ W Resistor?
A
B
C
D
12.
The color code is different
th
The 4 band is silver
The physical size is different
The leads are different length
Which of the following is the formula for heat dissipation?
A
B
C
D
Copyright © Texas Education Agency, 2013. All rights reserved.
12
Resistance Value and Tolerance Range Answer Key
Determine the resistance value and tolerance range of the following resistors.
1. A) Indicated resistance: 100000Ω
1.
B) Tolerance: 5000
C) Acceptable resistance value range: 95000 – 105000 Ω
2. A) Indicated resistance: 720000 Ω
B) Tolerance: 36000
2.
C) Acceptable resistance value range: 684,000 – 756,000 Ω
3.
3. A) Indicated resistance: 2200 Ω
4.
4. A) Indicated resistance: 65 Ω
5.
5. A) Indicated resistance: 4 Ω
6.
6. A) Indicated resistance: 1000 Ω
7.
7. A) Indicated resistance: 8000
B) Tolerance: 110 Ω
C) Acceptable resistance value range: 2090 – 2310 Ω
B) Tolerance: 3.25
C) Acceptable resistance value range: 61.75 – 68.25 Ω
B) Tolerance: .2
C) Acceptable resistance value range: 3.8 – 4.2 Ω
B) Tolerance: 100
C) Acceptable resistance value range: 900 – 1100 Ω
B) Tolerance: 400
C) Acceptable resistance value range: 7600 – 8400 Ω
8.
8. A) Indicated resistance: 1800000 Ω
B) Tolerance: 90,000
C) Acceptable resistance value range: 1710000 – 1891000 Ω
9.
9. A) Indicated resistance: 570 Ω
B) Tolerance: 28.5
C) Acceptable resistance value range: 541.5 – 598.5 Ω
10.
10. A) Indicated resistance: 200000 Ω
B) Tolerance: 10,000
C) Acceptable resistance value range: 190,000 – 210,000 Ω
11.
How would you tell a 1 W resistor from a ½ W Resistor?
A
The color code is different
B
The 4th band is silver
C
The physical size is different
D
The leads are different length
12.
Which of the following is the formula for heat dissipation?
A
B
C
D
Copyright © Texas Education Agency, 2013. All rights reserved.
13
Name ____________________________________________Date __________________Class ______
Resistors Color Code Activity
Fill in the lines with the correct value of each resistor.
1.
Red, Brown, Black, No Band
_________, _________, ________, ________
2.
Yellow, Red, Brown, Gold
_________, ________, _________, ________
3.
Blue, Red, Red, Silver
_________, ________, _________, ________
4.
Orange, Black, Black, Silver
_________, ________, _________, ________
5.
Red, Yellow, Orange, No Band
_________, ________, _________, ________
6.
Red, Violet, Brown, Silver
_________, ________, _________, ________
7.
Orange, White, Black, No Band
_________, ________, _________, ________
8.
Green, Blue, Orange, Gold
_________, ________, _________, ________
9.
Red, Red, Red, Gold
_________, ________, _________, ________
10.
Gray, Green, Yellow, No Band
_________, ________, _________, ________
Copyright © Texas Education Agency, 2013. All rights reserved.
14
Resistors Color Code Activity Answer Key
Fill in the lines with the correct value of each resistor.
1.
Red, Brown, Black, No Band
2______, 1______, none___, _20%___
(21 ohms +/- 4.2 or 16.8-25.2)
2.
Yellow, Red, Brown, Gold
4______, 2______, 0______, 5% _ ___
(420 ohms +/- 21 or 399-441)
3.
Blue, Red, Red, Silver
6______, 2______, 00_____, 10% ___
(6200 ohms +/- 620 or 5580-6820)
4.
Orange, Black, Black, Silver
3______, 0______, none___, 10%____
(30 ohms +/- 3 or 27-33)
5.
Red, Yellow, Orange, No Band
2______, 4______, 000____, 20%___
(24000 ohms +/- 4800 or 19200-28800)
6.
Red, Violet, Brown, Silver
2______, 7______, 0______, 10% ___
(270 ohms +/- 27 or 243-297)
7.
Orange, White, Black, No Band
3______, 9______, none___, 20%____
(39 ohms +/- 7.8 or 31.2-46.8)
8.
Green, Blue, Orange, Gold
5______, 6______, 000____, 5%_____
(56000 ohms +/- 2800 or 53200-58800)
9.
Red, Red, Red, Gold
2______, 2______, 00_____, 5%_____
(2200 ohms +/- 110 or 2090-2310)
10.
Gray, Green, Yellow, No Band
8______, 5______, 0000___, 20%____
(850,000 ohms +/- 170,000 or
680,000-1,020,000)
Copyright © Texas Education Agency, 2013. All rights reserved.
15
Name ____________________________________________Date __________________Class ______
Resistors Exam
Mark the best answer to each question.
1.
2.
3.
4.
5.
The resistor color code is used to express the value of all types of resistors.
 True
 False
In the resistor color code, black represents the number _______.
A
0
B
3
C
2
In the resistor color code, red represents the number _______.
A
0
B
1
C
2
In the resistor color code, orange represents the number _______.
A
0
B
3
C
2
In the resistor color code, brown represents the number _______.
A
0
B
1
C
2
6.
Decode the resistor.
Value __________
Tolerance __________
Brown, Black, Brown, Gold
7.
Decode the resistor.
Value __________
Tolerance __________
Red, Red, Brown, Silver
8.
Decode the resistor.
Value __________
Tolerance __________
Yellow, Violet, Red
9.
Decode the resistor.
Value __________
Tolerance __________
Orange, Orange, Orange, Gold
Copyright © Texas Education Agency, 2013. All rights reserved.
16
10.
Decode the resistor.
Value _________
Tolerance __________
Brown, Red, Yellow, Gold
Copyright © Texas Education Agency, 2013. All rights reserved.
17
Resistors Exam Key
Mark the best answer to each question.
1.
2.
3.
4.
5.
The resistor color code is used to express the value of all types of resistors.
True
 False
In the resistor color code, black represents the number _______.
A
0
B
3
C
2
In the resistor color code, red represents the number _______.
A
0
B
1
C
2
In the resistor color code, orange represents the number _______.
A
0
B
3
C
2
In the resistor color code, brown represents the number _______.
A
0
B
1
C
2
6.
Decode the resistor.
Value 100
Tolerance 5%
Brown, Black, Brown, Gold
7.
Decode the resistor.
Value 220
Tolerance 10%
Red, Red, Brown, Silver
8.
Decode the resistor.
Value 4.7k or 4,700
Tolerance 20%
Yellow, Violet, Red
9.
Decode the resistor.
Value 33k or 33,000
Tolerance 5%
Orange, Orange, Orange, Gold
Copyright © Texas Education Agency, 2013. All rights reserved.
18
10.
Decode the resistor.
Value 120k or 120,000
Tolerance 5%
Brown, Red, Yellow, Gold
Copyright © Texas Education Agency, 2013. All rights reserved.
19