Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 2nd Term
Week: 7
Age: 15 years
Duration: 45 minutes
Subject: Physics
Curriculum Theme: Physics
Previous Lesson: Gravitational Field.
Topic: ELECTRIC FIELD
Subject Matter: Electric lines of force, concept of electric field, electric current, potential difference, production of electric current, showing lines of force using a test positive charge, examples of electric field effects.

Specific Objectives

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

Cognitive Domain:

Define an electric field.
Describe electric lines of force and state their characteristics.
Differentiate between electric current and potential difference.
Explain how electric current can be produced.

Affective Domain:

Appreciate the presence and effects of electric fields in daily life.
Develop an interest in the study of electricity.

Psychomotor Domain:

Draw simple diagrams of electric field lines around charges.
Show the direction of an electric field using the concept of a test positive charge.

Participate actively in discussions about electric fields and their applications.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Physics.
State Unified Scheme of Work for Senior Secondary Schools.
New School Physics by M.W. Anyakoha.
Physics for Senior Secondary Schools by P.N. Okeke and O.E. Okeke.

Instructional Materials

The teacher will teach this lesson with the aid of:

Charts showing electric field lines around single and multiple charges.
Diagrams illustrating the concept of a test positive charge.
A whiteboard and markers.
Optional: Simple cells and wires to demonstrate current flow.

Rationale for the Lesson

This lesson helps pupils understand the fundamental concept of electric fields, which is important for grasping how charges interact and how electricity works. Understanding these concepts enables pupils to explain various electrical phenomena observed in their environment and daily life.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of electric charges, their types (positive and negative), and the concept of attraction and repulsion between charges.

Lesson Content/Board Summary

ELECTRIC FIELD

Concept of Electric Field

An electric field is defined as the region or space around an electric charge or a system of charges within which another charged particle would experience an electric force.

Electric Lines of Force

Electric lines of force are imaginary lines used to represent the direction and strength of an electric field. They indicate the path a free positive test charge would take if placed in the field.

The following are characteristics of electric lines of force:

They originate from positive charges and terminate on negative charges.
They never cross each other.
The density of the lines (how close they are) indicates the strength of the electric field; closer lines mean a stronger field.
They are always perpendicular to the surface of a conductor.
They exert lateral pressure on each other (repulsion).
They tend to contract longitudinally (attraction between opposite charges).

Showing lines of force using a test positive charge: A small, imaginary positive charge (called a test charge) is used to determine the direction of the electric field at any point. The direction of the force experienced by this test charge indicates the direction of the electric field at that point.

Electric Current

Electric current is defined as the rate of flow of electric charges (electrons) through a conductor. The SI unit of electric current is the Ampere (A).

Potential Difference

Potential difference (voltage) between two points in an electric field is the work done in moving a unit positive charge from one point to another. It is the driving force that causes electric current to flow. The SI unit of potential difference is the Volt (V).

Production of Electric Current

Electric current can be produced from various sources:

Chemical reactions: Found in batteries and cells (e.g., dry cells, car batteries).
Mechanical energy: Generators convert mechanical energy into electrical energy.
Light energy: Solar cells convert sunlight directly into electricity.
Heat energy: Thermocouples generate a small current when two different metals are heated at their junction.

Examples of Electric Field Effects

Electric fields have various effects and applications in daily life:

Lightning discharges during thunderstorms.
Operation of photocopiers and laser printers (electrostatic imaging).
Electrostatic painting (even coating of paint on surfaces).
Dust precipitators in industrial chimneys.
Electric shocks experienced from faulty appliances.

Teaching Methods/Instructional Techniques

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

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction/Recalling Previous Knowledge
Teacher’s Activity: The teacher greets the pupils, reviews the previous lesson on electric charges, and asks pupils about the interaction between different types of charges (attraction/repulsion). The teacher then introduces the topic “Electric Field” by asking how charges influence each other without touching.
Pupils’ Activity: Pupils respond to questions about charges and listen attentively to the introduction of the new topic.
Learning Point: Pupils recall previous knowledge on charges and are introduced to the concept of an electric field.

Step 2: Explanation of Electric Field and Lines of Force

Time: 10 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher defines an electric field and explains electric lines of force using charts to illustrate their direction and density around single positive, single negative, and pairs of charges. The teacher also states and explains the characteristics of electric lines of force.
Pupils’ Activity: Pupils observe the charts, listen to the explanations, and ask questions for clarification.
Learning Point: Pupils understand the concept of electric field and electric lines of force, including their characteristics.

Step 3: Introduction to Electric Current and Potential Difference

Time: 10 minutes
Teaching Skill: Definition/Comparison
Teacher’s Activity: The teacher defines electric current as the flow of charge and potential difference as the work done per unit charge. The teacher explains the difference between the two concepts and mentions their respective units (Ampere and Volt).
Pupils’ Activity: Pupils take notes, define the terms, and participate in discussions to differentiate between current and potential difference.
Learning Point: Pupils can define and differentiate between electric current and potential difference.

Step 4: Discussion on Production of Electric Current

Time: 5 minutes
Teaching Skill: Enumeration/Explanation
Teacher’s Activity: The teacher discusses various methods by which electric current can be produced, such as chemical reactions (batteries), mechanical energy (generators), and light energy (solar cells).
Pupils’ Activity: Pupils listen, contribute examples, and note down the different sources of electric current.
Learning Point: Pupils identify and explain different ways electric current is produced.

Step 5: Demonstration of Field Direction using a Test Positive Charge

Time: 5 minutes
Teaching Skill: Demonstration/Visualisation
Teacher’s Activity: The teacher uses a diagram or explains vividly how a small, imaginary positive test charge is used to determine the direction of an electric field at any point. The teacher shows how the force on this test charge determines the field direction.
Pupils’ Activity: Pupils observe the demonstration, ask questions, and practice drawing simple field lines based on the test charge concept.
Learning Point: Pupils understand how to use a test positive charge to determine electric field direction.

Step 6: Examples of Electric Field Effects

Time: 5 minutes
Teaching Skill: Application/Brainstorming
Teacher’s Activity: The teacher leads a discussion on various real-life examples and applications of electric fields, such as lightning, photocopiers, and electrostatic painting.
Pupils’ Activity: Pupils contribute examples from their daily experiences and discuss the effects of electric fields.
Learning Point: Pupils relate the concept of electric fields to practical applications and phenomena.

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 an electric field.
State two characteristics of electric lines of force.
Differentiate between electric current and potential difference.
Mention two ways electric current can be produced.
Explain how a test positive charge is used to show the direction of an electric field.

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, emphasizing the importance of understanding electric fields. The teacher then assigns homework related to drawing electric field patterns for different charge configurations.
Pupils’ Activity: Pupils listen to the summary and copy down the homework assignment.
Learning Point: Pupils consolidate their learning and are given tasks to reinforce understanding.

Lesson Keywords

Electric Field – The region around a charged body where another charge experiences a force.
Electric Lines of Force – Imaginary lines used to represent the direction and strength of an electric field.
Electric Current – The rate of flow of electric charges.
Potential Difference – The work done in moving a unit positive charge from one point to another in an electric field.
Test Charge – A small, imaginary positive charge used to determine the direction of an electric field.

Differentiation

For pupils who grasp concepts quickly, the teacher can provide additional challenges such as analyzing electric fields in three dimensions or researching advanced applications. For those needing more support, the teacher will use simplified diagrams, offer one-on-one explanations, and provide more practice questions with direct guidance.

Note for teachers using this lesson plan

Ensure that the charts used for electric field lines are clear and visible to all pupils. Encourage pupils to ask questions and engage in discussions to foster a deeper understanding of these abstract concepts. Practical demonstrations, if possible, can further enhance learning.