Lesson Plan: Resistors
Date: February 21st, 2013
Course: Life Skills 8
Lesson Objectives:
Time: 10 -15 minutes
Students will be able to describe what resistors are used for and use the resistor color code to
determine the value of a resistor
Introduction
Introduce resistors
-Resistors are the most common component in electronic circuits. Their purpose is to control
current flow and control voltage.
-Resistance is measured in units called Ohms. The symbol which is used to represent Ohm, is the
Greek letter omega which is used instead of writing the word Ohm. Show students the
schematic symbol for resistor.
Lesson Details
Carbon Film Resistor
-The most common type of resistor is the carbon film resistor. Each resistor has a number of
colored bands and each color has a numeric value. Resistor values are identified by a color code.
Show students a resistor color code chart. The color of the first and second bands each
represent a single digit between 0-9. The third colored band represents the number of 0’s placed
after the first two numbers. The fourth band represents the tolerance and is generally gold. A
gold band indicated + -5%. Tolerance means that the resistance value could be higher or lower
than its coded value. Example: a 1000 ohm + -5% could be as high as 1050 or as low as 950
How to use the code- Have students follow along by observing the document camera
Read the color code for the first digit and write it down. Read the color for the second digit and
write it down. We now have the 2 significant digits of the resistance code. Read the color code
for the third digit and add the amount of 0’s placed after the first 2 numbers.
Units
Resistance that are in thousands or millions of Ohms are better represented with other units.
The unit kilo or k is used to represent 1000. A 47000
resistor is better known as 47k .
If the resistance is in the millions, the unit used is Mega or M. A 12 000 000 ohm resistor is better
shown as 12M
Questions
Finish the lesson with a quick review
What is the most common component in electronic circuits? Resistor
What is the most common type of resistor? Carbon film
What does the unit kilo represent? 1000
What does the unit Mega represent? 1,000,000
Closure
Tell students to complete the resistor color code worksheet in their design portfolios. We will go
over the answers next class.
Assessment
- what changes or additions for next lesson
- student feed back/quiz/test=marks