Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 2nd Term
Week: 4
Age: 15 years
Duration: 45 minutes
Subject: GSM Maintenance And Repairs
Curriculum Theme: Trade
Previous Lesson: Simple Electric Circuits: Ohm’s Law And Electrical Quantities.
Topic: The Simple Electric Circuits
Subject Matter: Uses of resistors, Uses of capacitors, Uses of inductors, Colour coding of carbon resistors

Specific Objectives

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

Cognitive Domain:

State the uses of resistors, capacitors, and inductors.
Identify the colour code bands on carbon resistors.
Calculate the resistance value of a carbon resistor using its colour code.

Affective Domain:

Appreciate the importance of these components in electronic circuits.
Develop an interest in understanding electronic component specifications.

Psychomotor Domain:

Accurately identify the colour codes on given carbon resistors.
Demonstrate how to read and interpret resistor colour codes.

Discuss with peers the functions of various electronic components.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Basic Technology (JSS 1-3)
State Unified Scheme of Work for Senior Secondary Schools
Basic Electronics for Senior Secondary Schools by O.A. Okoro
https://www.allaboutcircuits.com/textbook/direct-current/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:

Assorted resistors
Assorted capacitors
Assorted inductors
A resistor colour code chart

Rationale for the Lesson

Understanding these components helps pupils grasp how electronic devices work and prepares them for practical repairs in GSM maintenance. This knowledge is fundamental for diagnosing faults and replacing parts effectively, leading to improved repair skills.

Prerequisite/Previous Knowledge

Pupils should have a basic understanding of electric current, voltage, and simple circuit components from previous lessons in Basic Technology.

Lesson Content/Board Summary

The Simple Electric Circuits

Uses of Resistors

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. Its main function is to oppose the flow of electric current.

The following are uses of resistors:

Limiting current flow in a circuit.
Dividing voltage in a circuit.
Adjusting signal levels.
Terminating transmission lines.

Uses of Capacitors

A capacitor is a passive two-terminal electrical component that stores electrical energy in an electric field. It consists of two electrical conductors separated by a dielectric (insulating) material.

The following are uses of capacitors:

Storing energy.
Filtering out noise in power supplies.
Timing circuits.
Coupling and decoupling AC signals.

Uses of Inductors

An inductor, also known as a coil or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. It typically consists of a conductor wound into a coil.

The following are uses of inductors:

Filtering out noise in power supplies (chokes).
Storing energy in switching power supplies.
Tuning circuits (e.g., in radios).
Blocking AC while allowing DC to pass.

Colour Coding of Carbon Resistors

Carbon resistors are small components whose resistance value is indicated by a series of coloured bands printed on their body. This system allows for quick identification of the resistance value, tolerance, and sometimes temperature coefficient.

The standard colour code uses four or five bands:

First Band: First significant digit.
Second Band: Second significant digit.
Third Band: Multiplier (power of 10).
Fourth Band: Tolerance (percentage accuracy).
(Fifth Band, if present): Temperature Coefficient.

The following table shows the common colour code values:

Black: 0 (Digit), 1 (Multiplier)
Brown: 1 (Digit), 10 (Multiplier), 1% (Tolerance)
Red: 2 (Digit), 100 (Multiplier), 2% (Tolerance)
Orange: 3 (Digit), 1,000 (Multiplier)
Yellow: 4 (Digit), 10,000 (Multiplier)
Green: 5 (Digit), 100,000 (Multiplier), 0.5% (Tolerance)
Blue: 6 (Digit), 1,000,000 (Multiplier), 0.25% (Tolerance)
Violet: 7 (Digit), 10,000,000 (Multiplier), 0.1% (Tolerance)
Grey: 8 (Digit), 100,000,000 (Multiplier), 0.05% (Tolerance)
White: 9 (Digit), 1,000,000,000 (Multiplier)
Gold: 0.1 (Multiplier), 5% (Tolerance)
Silver: 0.01 (Multiplier), 10% (Tolerance)
No Colour: 20% (Tolerance)

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 introduces the lesson by asking pupils to name some common electronic devices they use daily (e.g., mobile phones, radios). The teacher then asks what small components they might see inside these devices if they were opened.
Pupils’ Activity: Pupils mention various electronic devices and speculate about the small components within them.
Learning Point: Pupils are engaged and relate the topic to their daily experiences.

Step 2: Presentation of Resistors

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains what a resistor is and its fundamental role in a circuit. The teacher then lists and explains various uses of resistors, showing physical examples of different types of resistors.
Pupils’ Activity: Pupils listen attentively, observe the resistors, and ask questions for clarification. They note down the uses of resistors.
Learning Point: Pupils understand the definition and primary applications of resistors.

Step 3: Presentation of Capacitors

Time: 7 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains what a capacitor is, how it stores energy, and describes its common uses in electronic circuits. Physical examples of different capacitors (e.g., electrolytic, ceramic) are shown.
Pupils’ Activity: Pupils listen, observe the capacitors, and identify their differences. They note down the uses of capacitors.
Learning Point: Pupils understand the function and uses of capacitors.

Step 4: Presentation of Inductors

Time: 7 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains what an inductor is, how it stores energy in a magnetic field, and outlines its key applications in electronics. Various types of inductors are presented.
Pupils’ Activity: Pupils listen, observe the inductors, and compare them with other components. They note down the uses of inductors.
Learning Point: Pupils understand the function and uses of inductors.

Step 5: Presentation of Colour Coding of Carbon Resistors

Time: 8 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher explains the necessity of colour coding for small components like carbon resistors. Using the colour code chart and actual resistors, the teacher demonstrates how to read the colour bands to determine resistance value and tolerance. The teacher provides a few examples for calculation.
Pupils’ Activity: Pupils observe the colour code chart and the resistors, practicing how to read the bands. They attempt to calculate resistance values from examples given by the teacher.
Learning Point: Pupils learn the system of resistor colour coding and how to interpret it.

Step 6: Practical Application/Guided Practice

Time: 3 minutes
Teaching Skill: Practical Application/Feedback
Teacher’s Activity: The teacher distributes a few resistors to groups of pupils and asks them to identify the colour codes and state the resistance value and tolerance. The teacher walks around, offering guidance and correcting errors.
Pupils’ Activity: Pupils work in groups to identify resistor values and practice reading colour codes.
Learning Point: Pupils gain practical experience in identifying and calculating resistor values.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

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

Define a resistor and state two of its uses.
Mention two uses of a capacitor in electronic circuits.
How is an inductor primarily used in electronics?
Explain the purpose of colour coding on carbon resistors.
A resistor has colour bands: Red, Green, Orange, Gold. What is its resistance value and tolerance?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key learning points about the uses of resistors, capacitors, inductors, and the importance of colour coding in identifying resistor values. The teacher encourages pupils to observe these components in everyday electronic devices.
Pupils’ Activity: Pupils listen and ask any final questions.
Learning Point: Pupils consolidate their understanding of the lesson.

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.
Inductor – An electronic component that stores energy in a magnetic field.
Colour Code – A system using coloured bands to indicate the value and tolerance of a resistor.
Tolerance – The permissible variation in the actual value of a component from its marked value.

Differentiation

For pupils who grasp the concepts quickly, the teacher can provide more complex resistor colour code challenges or ask them to research other types of resistors or capacitors. For those needing more support, the teacher will provide additional individual guidance and simplified colour code practice, focusing on understanding the first three bands before moving to tolerance.

Note for teachers using this lesson plan

Teachers should ensure they have actual physical components (resistors, capacitors, inductors) and a clear colour code chart to make the lesson practical and engaging. Encourage pupils to handle the components carefully. Emphasize the safety precautions when dealing with electronic components and circuits, even simple ones. Practical demonstration and hands-on activities are essential for effective learning in this subject.