Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: First Term
Week: 10
Age: 15 years
Duration: 45 minutes
Subject: Radio, Tv & Electronics
Curriculum Theme: Trade
Previous Lesson: Electronic Components: Identification, Types And Symbols.
Topic: ELECTRONIC COMPONENTS
Subject Matter: Calculation of values, Component ratings, Resistor color codes, Capacitor values

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

State the meaning of resistor color codes.
Identify the color bands on a resistor.
Explain how to determine capacitor values.
List common component ratings.

Affective Domain:

Appreciate the importance of accurate component value identification.
Show interest in performing calculations for electronic components.

Psychomotor Domain:

Calculate the resistance value of a resistor using its color code.
Identify the value of a capacitor from its markings.
Demonstrate how to handle different electronic components.

Collaborate with peers to solve problems related to component values.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Basic Technology (JSS 1-3) & Trade Subjects (SSS 1-3)
State Unified Scheme of Work for Radio, TV & Electronics (SSS 1)
Radio, TV & Electronics for Senior Secondary Schools by A.O. Akinyemi
https://www.allaboutcircuits.com/textbook/semiconductors/chpt-2/resistor-color-codes/
https://www.electronics-tutorials.ws/capacitor/cap_1.html

Instructional Materials

The teacher will teach this lesson with the aid of:

Resistor color chart
Sample resistors of various values
Sample capacitors
Calculator
Whiteboard and markers

Rationale for the Lesson

This lesson helps pupils understand how to identify and read the values of basic electronic components. This knowledge is important for selecting the correct components for circuits and for troubleshooting electronic devices, which are practical skills in the field of electronics.

Prerequisite/Previous Knowledge

Pupils have some basic understanding of electronic components like resistors and capacitors from previous lessons.

Lesson Content/Board Summary

ELECTRONIC COMPONENTS: VALUES AND RATINGS

Resistor Color Codes

Resistors use a system of colored bands to indicate their resistance value and tolerance. Each color represents a numerical digit, a multiplier, or a tolerance value.

The following are the standard resistor color code values:

Black – 0
Brown – 1
Red – 2
Orange – 3
Yellow – 4
Green – 5
Blue – 6
Violet – 7
Grey – 8
White – 9

Common tolerance colors are:

Gold – ±5%
Silver – ±10%
No band – ±20%

To read a 4-band resistor: The first band is the first digit, the second band is the second digit, the third band is the multiplier, and the fourth band is the tolerance.

Capacitor Values

Capacitors store electrical energy. Their value, called capacitance, is measured in Farads (F), though microfarads (µF), nanofarads (nF), and picofarads (pF) are more common.

The following are ways to determine capacitor values:

Direct Marking: Larger capacitors often have their value printed directly on them (e.g., 10µF, 47nF).
Numeric Codes: Smaller capacitors may use a 3-digit code (e.g., 104 = 10 x 10^4 pF = 100,000 pF = 0.1 µF). The first two digits are the significant figures, and the third is the multiplier (power of 10 in pF).
Color Codes: Some older or specialized capacitors may use a color code similar to resistors.

Component Ratings

Component ratings specify the maximum electrical limits a component can safely handle without damage or failure. Exceeding these ratings can lead to component breakdown.

The following are common component ratings:

Voltage Rating: Maximum voltage that can be applied across the component (e.g., 50V for capacitors).
Current Rating: Maximum current that can flow through the component (e.g., 1A for fuses, 500mA for diodes).
Power Rating: Maximum power a component can dissipate (e.g., 0.25W for resistors).
Temperature Rating: Operating temperature range.

Calculation of Values

Calculating values involves applying the rules of color codes or numeric markings. For resistors, once the color bands are identified, the numerical value is derived using the standard chart. For capacitors, direct reading or code interpretation provides the value.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to mention some basic electronic components they know. The teacher then introduces the topic: “Electronic Components: Calculation of Values, Component Ratings, Resistor Color Codes, Capacitor Values,” explaining that identifying the correct values is essential in electronics.
Pupils’ Activity: Pupils respond to the teacher’s questions and listen attentively to the introduction.
Learning Point: Pupils recall previous knowledge of electronic components and understand the focus of the lesson.

Step 2: Resistor Color Codes

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher displays a resistor color chart and sample resistors. The teacher explains the resistor color code system, demonstrating how each band represents a digit, multiplier, and tolerance using the chart and actual resistors. The teacher writes examples on the board.
Pupils’ Activity: Pupils observe the chart and resistors, listen to the explanation, and copy notes from the board. They ask questions for clarification.
Learning Point: Pupils understand the resistor color code system and can identify the meaning of each band.

Step 3: Calculating Resistor Values

Time: 8 minutes
Teaching Skill: Practical Application/Guided Practice
Teacher’s Activity: The teacher demonstrates step-by-step how to calculate the resistance value of a resistor using its color bands with several examples. For instance, Brown-Green-Red-Gold. The teacher guides pupils through a calculation.
Pupils’ Activity: Pupils follow the teacher’s demonstration, calculate along with the teacher, and practice on provided examples.
Learning Point: Pupils learn to apply the color code rules to calculate resistor values.

Step 4: Capacitor Values

Time: 7 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher shows different types of capacitors (e.g., electrolytic, ceramic) and explains how their values are typically marked—either directly printed or using a 3-digit numeric code. The teacher clarifies units like µF, nF, and pF.
Pupils’ Activity: Pupils observe the sample capacitors, listen to the explanation, and identify markings. They ask questions about the units and codes.
Learning Point: Pupils understand how to read capacitor values from their markings.

Step 5: Component Ratings

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher explains the concept of component ratings (voltage, current, power) and why they are important for safe circuit design and operation. The teacher gives examples of typical ratings for resistors and capacitors.
Pupils’ Activity: Pupils listen and understand the importance of not exceeding component ratings.
Learning Point: Pupils learn about various component ratings and their significance.

Step 6: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

What is the resistance value of a resistor with color bands: Yellow, Violet, Orange, Gold?
Mention two ways to identify the value of a capacitor.
State two common component ratings.
Why is it important to consider component ratings when designing a circuit?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 7: Conclusion

Time: 5 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the importance of accurately identifying component values and ratings. The teacher assigns homework: Ask pupils to find and list the color codes for at least five different resistors at home or in the school lab.
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their understanding and prepare for further practice.

Lesson Keywords

Resistor – An electronic component that opposes the flow of electric current.
Capacitor – An electronic component that stores electrical energy in an electric field.
Color Code – A system of colored bands used to indicate the value and tolerance of a resistor.
Capacitance – The ability of a capacitor to store an electric charge, measured in Farads.
Component Rating – The maximum electrical limits (e.g., voltage, current, power) a component can safely handle.

Differentiation

For pupils who grasp the concepts quickly, the teacher can provide more complex resistor color code examples (e.g., 5-band resistors) or introduce series/parallel calculations for resistors. For pupils needing more support, the teacher will provide additional one-on-one guidance and simpler color code examples, using the color chart more extensively.

Note for teachers using this lesson plan

Ensure that actual resistors and capacitors are available for pupils to handle and observe. The resistor color chart should be clear and visible to all pupils. Encourage pupils to practice reading values from various components to build confidence. Emphasize the practical implications of understanding component values and ratings for safety and functionality in electronics.