Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: Second Term
Week: 4
Age: 15 years
Duration: 45 minutes
Subject: Basic Electronics
Curriculum Theme: Basic Electronics
Previous Lesson: Electric Power: Deriving Power.
Topic: CIRCUIT COMPONENTS Concept of resistors. Symbols, sign and unit of resistance.
Subject Matter: concept of a resistor, functions of resistors in circuits, types of resistors, symbol of resistor, unit of resistance and meaning of ohm

Specific Objectives

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

Cognitive Domain:

Define a resistor.
State at least two functions of resistors in circuits.
Identify different types of resistors.
State the unit of resistance and its meaning.

Affective Domain:

Appreciate the importance of resistors in various electronic devices.
Show interest in identifying resistor symbols in circuit diagrams.

Psychomotor Domain:

Draw the standard symbol for a fixed resistor.
Identify different types of resistors from physical samples.

Collaborate with peers to discuss the applications of resistors.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Basic Technology.
State Unified Scheme of Work for Basic Electronics (SSS 1).
Basic Electronics for Senior Secondary Schools by A.O. Okoro.

Instructional Materials

The teacher will teach this lesson with the aid of:

Assorted resistors (fixed, variable).
Charts showing resistor symbols.
Whiteboard/Blackboard and markers/chalk.

Rationale for the Lesson

This lesson helps pupils understand a fundamental component of all electronic devices. Understanding resistors enables pupils to grasp how current flow is controlled and regulated in circuits, which is important for basic electronics knowledge and practical applications.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of electric current, voltage, and simple electrical circuits.

Lesson Content/Board Summary

Concept of Resistors

What is a Resistor?

A resistor is an electronic component that opposes or limits the flow of electric current in a circuit. It introduces electrical resistance into a circuit.

Functions of Resistors in Circuits

The following are the functions of resistors:

To limit the flow of current.
To divide voltage in a circuit.
To generate heat (e.g., in heating elements).
To provide specific voltage levels for other components.

Types of Resistors

Resistors are broadly classified into two main types:

Fixed Resistors: These resistors have a resistance value that does not change. Their resistance value is permanent and cannot be adjusted. Examples include carbon composition resistors, metal film resistors, and wire-wound resistors.
Variable Resistors: These resistors have a resistance value that can be changed or adjusted. Examples include potentiometers (used for volume control), rheostats (used for current control), and thermistors (resistance changes with temperature).

Symbol of Resistor

The standard symbol for a fixed resistor in a circuit diagram is a zigzag line. For a variable resistor, it is a zigzag line with an arrow pointing to it.

Unit of Resistance and Meaning of Ohm

The unit of resistance is the Ohm, represented by the Greek letter Omega (Ω). One Ohm is defined as the resistance between two points in a conductor where a potential difference of one volt drives a current of one ampere.

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 questions to link to previous knowledge, such as “What is electric current?” and “What makes a light bulb glow?” The teacher then introduces the topic by stating that for a light bulb to glow correctly, the current flowing through it must be controlled, and this control is achieved by components called resistors.
Pupils’ Activity: Pupils respond to questions and listen attentively.
Learning Point: Pupils recall previous knowledge and are prepared for the new topic.

Step 2: Explanation of Resistors

Time: 7 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher defines a resistor as an electronic component that opposes the flow of electric current. The teacher shows physical samples of various resistors and explains their basic function in controlling current.
Pupils’ Activity: Pupils observe the samples and listen to the explanation, asking questions for clarification.
Learning Point: Pupils understand the definition and basic function of a resistor.

Step 3: Functions of Resistors

Time: 7 minutes
Teaching Skill: Explanation/Listing
Teacher’s Activity: The teacher explains and lists the various functions of resistors in a circuit, such as limiting current, dividing voltage, and generating heat, providing simple examples for each.
Pupils’ Activity: Pupils listen, take notes, and contribute examples if possible.
Learning Point: Pupils learn the practical roles of resistors in electronic circuits.

Step 4: Types of Resistors

Time: 7 minutes
Teaching Skill: Classification/Demonstration
Teacher’s Activity: The teacher explains the two main types of resistors (fixed and variable), showing physical examples of each. The teacher highlights the difference between them and mentions common sub-types.
Pupils’ Activity: Pupils observe the different resistor types, identify their characteristics, and ask questions.
Learning Point: Pupils can differentiate between fixed and variable resistors.

Step 5: Resistor Symbols

Time: 5 minutes
Teaching Skill: Drawing/Illustration
Teacher’s Activity: The teacher draws the standard symbols for fixed and variable resistors on the board or uses a chart. The teacher explains what each symbol represents in a circuit diagram.
Pupils’ Activity: Pupils observe the symbols, draw them in their notebooks, and understand their meaning.
Learning Point: Pupils can draw and identify resistor symbols.

Step 6: Unit of Resistance

Time: 4 minutes
Teaching Skill: Explanation/Defining
Teacher’s Activity: The teacher introduces the unit of resistance, the Ohm (Ω), and explains its meaning. The teacher may briefly mention its relation to voltage and current (Ohm’s Law) without going into detailed calculations.
Pupils’ Activity: Pupils listen, note down the unit and its symbol, and understand the concept of Ohm.
Learning Point: Pupils know the unit of resistance and its definition.

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.
State two functions of a resistor in a circuit.
Mention two types of resistors.
Draw the symbol for a fixed resistor.
What is the unit of resistance?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 5 minutes
Teaching Skill: Summarization/Assignment
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the definition, functions, types, symbols, and unit of resistors. The teacher then assigns homework, asking pupils to research common applications of resistors in household appliances.
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their learning and are encouraged to explore further.

Lesson Keywords

Resistor – An electronic component that opposes the flow of electric current.
Resistance – The opposition to the flow of electric current.
Ohm – The standard unit of electrical resistance.
Fixed Resistor – A resistor with a constant, unchangeable resistance value.
Variable Resistor – A resistor whose resistance value can be adjusted.
Circuit – A closed path through which electric current flows.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to identify specific resistor values using color codes. For pupils needing more support, the teacher can provide simplified diagrams and allow peer tutoring or extra time for drawing symbols and identifying resistor types from samples.

Note for teachers using this lesson plan

Teachers should ensure they have enough physical samples of various resistors to make the demonstration effective. Encourage pupils to handle the components carefully. Emphasize the practical relevance of resistors in everyday electronic gadgets to maintain pupil engagement.