Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: First Term
Week: 9
Age: 15 years
Duration: 45 minutes
Subject: Basic Electronics
Curriculum Theme: Basic Electronics
Previous Lesson: Measuring Voltage, Current and Resistance.
Topic: RELATIONSHIP BETWEEN VOLTAGE CURRENT AND RESISTANCE Ohm’s law
Subject Matter: definition of Ohm’s law, mathematical expression of Ohm’s law, identifying V I R in equations, applying Ohm’s law to simple circuit values

Specific Objectives

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

Cognitive Domain:

Define Ohm’s law.
State the mathematical expression of Ohm’s law.
Identify voltage (V), current (I), and resistance (R) in equations.

Affective Domain:

Appreciate the importance of Ohm’s law in electrical circuits.
Show interest in solving problems related to electrical quantities.

Psychomotor Domain:

Apply Ohm’s law to calculate unknown values in simple circuit problems.
Manipulate the Ohm’s law formula to find voltage, current, or resistance.

Participate actively in class discussions and problem-solving exercises.
Collaborate with peers to solve simple circuit problems.

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 relevant author.

Instructional Materials

The teacher will teach this lesson with the aid of:

Calculator
Charts illustrating Ohm’s law triangle and simple circuits
Whiteboard/Chalkboard
Markers/Chalk

Rationale for the Lesson

This lesson helps pupils understand the fundamental relationship between voltage, current, and resistance in electrical circuits. Understanding Ohm’s law is important for analyzing and designing basic electronic circuits and for daily applications of electricity.

Prerequisite/Previous Knowledge

Pupils should have a basic understanding of electricity, including the concepts of voltage, current, and resistance, from previous lessons.

Lesson Content/Board Summary

Ohm’s Law

Definition of Ohm’s Law

Ohm’s law states that the current flowing through a metallic conductor is directly proportional to the voltage across its ends, provided that the temperature and other physical conditions remain constant.

Mathematical Expression of Ohm’s Law

Ohm’s law can be expressed mathematically in three forms:

V = I x R (Voltage = Current x Resistance)
I = V / R (Current = Voltage / Resistance)
R = V / I (Resistance = Voltage / Current)

Identifying Voltage, Current, and Resistance (V, I, R) in Equations

In the Ohm’s law equations:

V represents Voltage, measured in Volts (V).
I represents Current, measured in Amperes (A).
R represents Resistance, measured in Ohms (Ω).

Application of Ohm’s Law to Simple Circuit Values

Ohm’s law is used to calculate any one of the three quantities (V, I, R) if the other two are known.
The following are examples of applying Ohm’s law:

Example 1: If a circuit has a voltage of 12V and a resistance of 4Ω, the current (I) is I = V/R = 12V/4Ω = 3A.
Example 2: If a current of 2A flows through a resistor of 5Ω, the voltage (V) across the resistor is V = I x R = 2A x 5Ω = 10V.
Example 3: If a voltage of 24V causes a current of 6A to flow, the resistance (R) is R = V/I = 24V/6A = 4Ω.

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 reviews the previous lesson on basic electrical quantities (voltage, current, resistance). The teacher then asks pupils what they think connects these three quantities in a circuit.
Pupils’ Activity: Pupils respond to the greetings and questions, recalling previous knowledge.
Learning Point: Pupils recall prior knowledge and are prepared for the new topic.

Step 2: Presentation of Ohm’s Law Definition

Time: 8 minutes
Teaching Skill: Explanation/Lecture
Teacher’s Activity: The teacher states Ohm’s law clearly and explains its meaning, emphasizing the conditions under which it applies (constant temperature and physical conditions). The teacher writes the definition on the board.
Pupils’ Activity: Pupils listen attentively, ask questions for clarification, and copy the definition into their notebooks.
Learning Point: Pupils understand and can state the definition of Ohm’s law.

Step 3: Mathematical Expression of Ohm’s Law

Time: 7 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher introduces the mathematical expression V = I x R and shows how it can be rearranged to find I and R. The teacher uses a chart or draws the Ohm’s law triangle to help pupils remember the formulas.
Pupils’ Activity: Pupils observe the demonstration, copy the formulas, and ask questions regarding the rearrangement.
Learning Point: Pupils can write the mathematical expressions for Ohm’s law and identify the variables.

Step 4: Identifying V, I, R in Equations

Time: 7 minutes
Teaching Skill: Explanation/Questioning
Teacher’s Activity: The teacher clearly explains what each symbol (V, I, R) represents and their respective standard units (Volts, Amperes, Ohms). The teacher asks pupils to identify the symbols and units in various simple statements.
Pupils’ Activity: Pupils correctly identify V, I, R and their units when prompted by the teacher.
Learning Point: Pupils can identify voltage, current, and resistance symbols and units.

Step 5: Application of Ohm’s Law (Worked Examples)

Time: 8 minutes
Teaching Skill: Problem Solving/Demonstration
Teacher’s Activity: The teacher works through one or two examples on the board, demonstrating how to apply Ohm’s law to calculate unknown values (V, I, or R) in simple circuits, using the calculator as needed.
Pupils’ Activity: Pupils pay attention to the steps, ask questions, and follow along with their calculators.
Learning Point: Pupils learn the process of applying Ohm’s law to solve problems.

Step 6: Class Activity/Practice

Time: 5 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher writes a simple problem on the board and asks pupils to solve it individually or in pairs. The teacher walks around to provide assistance.
Pupils’ Activity: Pupils attempt to solve the given problem, applying the formulas learned.
Learning Point: Pupils practice applying Ohm’s law and reinforce their understanding.

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 Ohm’s law.
State the three mathematical expressions of Ohm’s law.
What does the symbol ‘I’ represent in Ohm’s law, and what is its unit?
A circuit has a voltage of 20V and a current of 4A. Calculate the resistance.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 1 minute
Teaching Skill: Recap/Summarization
Teacher’s Activity: The teacher briefly summarizes the key points of the lesson, reiterating the importance of Ohm’s law in electronics. The teacher assigns homework which involves solving more problems on Ohm’s law.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils consolidate their learning and prepare for further practice.

Lesson Keywords

Ohm’s Law – A fundamental law in electronics that relates voltage, current, and resistance.
Voltage (V) – The electrical potential difference between two points, measured in Volts.
Current (I) – The flow of electric charge, measured in Amperes.
Resistance (R) – The opposition to the flow of electric current, measured in Ohms.
Circuit – A closed loop through which current can flow.

Differentiation

For pupils who grasp the concept quickly, the teacher can provide more complex problems involving series and parallel combinations of resistors. For pupils who need more support, the teacher will provide simplified problems with step-by-step guidance and offer individual attention during the practice session.

Note for teachers using this lesson plan

Ensure that pupils understand the concept of proportionality before introducing Ohm’s law. Emphasize the units of measurement for voltage, current, and resistance, as this is important for accurate calculations. Encourage pupils to use calculators for problem-solving and to always show their working steps.