Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 1st Term
Week: 11
Age: 15 years
Duration: 45 minutes
Subject: Basic Electronics
Curriculum Theme: Basic Electronics
Previous Lesson: Ohm’s Law: Practical Experiment and Graph.
Topic: RELATIONSHIP BETWEEN VOLTAGE, RESISTANCE AND CURRENT
Subject Matter: Calculating current using V and R, calculating voltage using I and R, calculating resistance using V and I, solving simple circuit problems using Ohm’s law

Specific Objectives

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

Cognitive Domain:

Define Ohm’s Law.
State the relationship between voltage, current, and resistance.
Recall the formulas for calculating current, voltage, and resistance.
Calculate current, voltage, or resistance given the other two values.

Affective Domain:

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

Psychomotor Domain:

Apply Ohm’s Law formulas correctly to solve numerical problems.
Use a calculator efficiently for circuit calculations.

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 (Senior Secondary).
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:

Calculators
Circuit diagrams (on cardboard or drawn on the whiteboard)
Whiteboard and markers

Rationale for the Lesson

Understanding the relationship between voltage, current, and resistance helps pupils to comprehend how electrical components behave in a circuit. This knowledge is important for troubleshooting simple electrical faults and for further studies in electronics.

Prerequisite/Previous Knowledge

Pupils have a basic understanding of electric current, voltage, and resistance as individual electrical quantities.

Lesson Content/Board Summary

RELATIONSHIP BETWEEN VOLTAGE, RESISTANCE AND CURRENT

Ohm’s Law

Ohm’s Law states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them, provided the temperature and other physical conditions remain constant.

The formula for Ohm’s Law is:

V = I × R
Where:

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

Calculating Current (I)

To calculate current, the formula derived from Ohm’s Law is:

I = V / R

Example: A circuit has a voltage of 12 V and a resistance of 4 Ω. Calculate the current flowing through it.

Solution: I = V / R = 12 V / 4 Ω = 3 A.

Calculating Voltage (V)

To calculate voltage, the formula from Ohm’s Law is:

V = I × R

Example: A current of 2 A flows through a resistor of 10 Ω. Calculate the voltage across the resistor.

Solution: V = I × R = 2 A × 10 Ω = 20 V.

Calculating Resistance (R)

To calculate resistance, the formula derived from Ohm’s Law is:

R = V / I

Example: A voltage of 6 V is applied across a component, and a current of 0.5 A flows through it. Calculate the resistance of the component.

Solution: R = V / I = 6 V / 0.5 A = 12 Ω.

Solving Simple Circuit Problems

When solving simple circuit problems involving Ohm’s Law, follow these steps:

Identify the known values (V, I, or R).
Identify the unknown value to be calculated.
Select the appropriate Ohm’s Law formula.
Substitute the known values into the formula.
Perform the calculation and state the answer with the correct unit.

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 introduces the topic by asking pupils if they know how these quantities are related in a circuit.
Pupils’ Activity: Pupils respond to the teacher’s questions and recall aspects of the previous lesson.
Learning Point: Pupils recall previous knowledge and are prepared for the new topic.

Step 2: Understanding Ohm’s Law

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher defines Ohm’s Law and explains the direct and inverse relationships between voltage, current, and resistance. The teacher writes the main formula (V=IR) and its derivations (I=V/R, R=V/I) on the board, explaining each variable and its unit.
Pupils’ Activity: Pupils listen attentively, copy notes, and ask questions for clarification.
Learning Point: Pupils understand the statement of Ohm’s Law and its fundamental formula.

Step 3: Calculating Current

Time: 7 minutes
Teaching Skill: Problem Solving/Demonstration
Teacher’s Activity: The teacher demonstrates how to calculate current using the formula I = V/R, working through a simple example on the board. The teacher ensures pupils understand the substitution and calculation process.
Pupils’ Activity: Pupils observe the demonstration, follow the steps, and attempt to solve the example in their notebooks.
Learning Point: Pupils learn to apply the formula for calculating current.

Step 4: Calculating Voltage

Time: 7 minutes
Teaching Skill: Problem Solving/Demonstration
Teacher’s Activity: The teacher guides pupils through another example, this time calculating voltage using the formula V = I × R. The teacher emphasizes the importance of using correct units.
Pupils’ Activity: Pupils work along with the teacher, solving the example and ensuring they use correct units.
Learning Point: Pupils learn to apply the formula for calculating voltage.

Step 5: Calculating Resistance

Time: 7 minutes
Teaching Skill: Problem Solving/Demonstration
Teacher’s Activity: The teacher presents an example for calculating resistance using the formula R = V/I. The teacher encourages pupils to attempt the calculation before revealing the answer.
Pupils’ Activity: Pupils calculate the resistance for the given example and compare their answers with the teacher’s.
Learning Point: Pupils learn to apply the formula for calculating resistance.

Step 6: Class Activity/Problem Solving

Time: 7 minutes
Teaching Skill: Application/Group Work
Teacher’s Activity: The teacher provides a few simple circuit problems involving calculations of V, I, or R. The teacher asks pupils to work individually or in pairs to solve them, circulating to provide assistance.
Pupils’ Activity: Pupils work on the given problems, applying the learned formulas, and seek help when needed.
Learning Point: Pupils apply Ohm’s Law to solve various circuit problems.

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 formula for Ohm’s Law and identify the variables.
A resistor of 5 Ω has a voltage of 15 V across it. Calculate the current flowing through the resistor.
If a current of 0.5 A flows through a 20 Ω resistor, what is the voltage across the resistor?

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 main points of the lesson, reiterating the importance of Ohm’s Law in basic electronics. The teacher gives homework, asking pupils to solve additional problems involving Ohm’s Law.
Pupils’ Activity: Pupils listen to the summary and copy down the homework assignment.
Learning Point: Pupils consolidate their understanding of the topic.

Lesson Keywords

Voltage – The electrical potential difference between two points in a circuit.
Current – The flow of electric charge per unit time.
Resistance – The opposition to the flow of electric current.
Ohm’s Law – A fundamental law stating the relationship between voltage, current, and resistance in an electrical circuit.
Circuit – A closed loop through which electricity can flow.

Differentiation

For pupils who grasp the concept quickly, the teacher will provide more complex problems involving series or parallel combinations of resistors. For pupils who are struggling, the teacher will provide additional direct practice with simpler calculations and offer one-on-one support.

Note for teachers using this lesson plan

Ensure that pupils are comfortable with basic algebra for rearranging formulas. Emphasize the importance of units in all calculations. Encourage pupils to draw simple circuit diagrams for each problem to visualize the components and values.