ELECTRONICS
I. Objectives

To determine a resistors value by examining its color bands.

To determine if the resistors as within tolerance.
II. Subject mater
Topic: Resistance Measurement
Reference: EDocfind.com, From Wikipedia, the free encyclopedia, and http://www.educypedia.be/electronics/
Materials: Colored Resistors, Calculator
III. Activities
1. Review a. What is resistor?

Resistors are Electronic components that are designed to have a specific amount of resistance. b. Types of resistor? Meaning?

There are two types of resistors; Fixed and Variable Resistors. o Fixed Resistors the value cannot change. o Variable Resistors can change their value over a specific range. c. Kinds of Fixed Resistors?

There several kinds of fixed resistors such as composition carbon, metal film, and wire – wound.
2. Motivation
Have you seen resistor? o Yes.
What have you notice to the Resistor? o It has different colors.
3. Presentation
A. Discussion
Teacher’s Activity a. What Is Resistance? b. What are the three most important characteristics of a resistor are? c. How the Resistance of the Resistors
Measured? d. How do we know which color corresponds to which number? e. What is Resistor Color Code?
Student’s Activity
Resistance (R) is the amount of opposition to the flow of electrical current.
Resistance is measured in units called ohms, named after German scientist and mathematician Georg Simon Ohm
(1787-1845), and it is symbolized by the
Greek capital letter omega (W).
1. Resistance Nominal Value
2. Tolerance
3. Power Rating
Trough it’s color bands.
By using the Resistor Color Code.

Resistor Color Code f. Which side of a resistor do I read from?
Converting the Nominal Resistance and
Tolerance into the Color Code.
4-Band Resistors
1. Resistors with

5% and

10% Tolerance will have 4-bands
2. Convert nominal value to ohms (

)
3. 1 st digit (from left to right) of nominal value =
1 st color band
4. 2 nd digit of nominal value = 2 nd band
5. Number of zeros remaining = 3 rd (multiplier) band
6. Tolerance = 4 th band
5-Band Resistors
1. Resistors with

1% and

2% Tolerance will have 5-bands
2. Convert nominal value to ohms (

)
3. 1 st digit (from left to right) of nominal value =
1 st color band
4. 2 nd digit of nominal value = 2 nd band
5. 3 rd digit of nominal value = 3 rd band
6. Number of zeros remaining = 4 th (multiplier) band
7. Tolerance = 5 th band
Tolerance Bands
To calculate tolerance range
1. Determine the resistors stated resistance
In order to identify the nominal resistance and the tolerance of a resistor, manufacturers typically use a color band system known as the resistor color code.
For 4-band resistors a gold or silver band is always the last band.
If the resistor has 5 bands or if there is no tolerance band (±20%), then the first band is the one located closest to a lead.

from the color bands.
2. Multiply the stated resistance times (x) the tolerance percentage.
3. Add and Subtract your tolerance figure from the stated resistance to identify the acceptable range.
Example 1.
Determine the nominal resistance value and the tolerance for the resistor shown below.
10 x ± %
Calculate the Tolerance.
Example 2.
10 x
± %
Example 3.
10 x
± %
2 2 10 x 2 ± 5%
2,200 Ω x .05 (or 5%)
= +/- 110 Ohms tolerance
Maximum
2,200 Ω + 110 Ω = 2310 Ω
Minimum
2,200 Ω – 110 Ω = 2090 Ω
4 7 10 x 3
or 47K
Ω
± 5%
47 K Ω x .05 (or 5%)
= +/-
2.35 K Ω tolerance
Maximum
47 K Ω + 2.35 K Ω = 49.35 K Ω
Minimum
47 K Ω – 2.35 K Ω = 44.65 K Ω

4. Application
The teacher will group the student into three.
The teacher will provide the colored resistors.
Each group will get five colored resistor.
They will calculate the resistance and get the maximum and minimum tolerance of the colored resistors.
They will write their answer with solution to
1 0 0 10 x 1 ± 2%
1,000
Ω x .02 (or 2%)
= +/- 20 Ω tolerance
Maximum
1,000
Minimum
Ω + 20 Ω = 1,020 Ω
1,000
Ω – 20 Ω = 980 Ω one whole sheet of paper.
5. Evaluation
A.
Calculate the Stated Resistance for the Resistor
1. What is the stated Resistance and tolerance percentage?___________ Ω (2 pts.)
2. What is the Tolerance of the resistor?___________
Ω (3 pts.)
3. The resistor is working properly if it measures between ___________
Ω
and ___________ Ω of resistance. (5 pts.) (show the solution)
B.
Calculate the Stated Resistance for the Resistor
1. What is the stated Resistance and tolerance percentage?___________ Ω (2 pts.)
2. What is the Tolerance of the resistor?___________ Ω (3 pts.)
3. The resistor is working properly if it measures between ___________
Ω
and ___________
Ω of resistance. (5 pts.) (show the solution)
C.
Calculate the Stated Resistance for the Resistor
1. What is the stated Resistance and tolerance percentage?___________
Ω (2 pts.)
2. What is the Tolerance of the resistor?___________ Ω (3 pts.)
3. The resistor is working properly if it measures between ___________ Ω
and ___________
Ω of resistance. (5 pts.) (show the solution)
Prepared by,
___________________________
JOHN HOWARD NOMBREFIA