Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: First Term
Week: 9
Age: 15 years
Duration: 45 minutes
Subject: Basic Electricity
Curriculum Theme: Basic Electricity
Previous Lesson: Capacitors: Types, Symbols and Applications.
Topic: CAPACITOR COLOR CODING.
Subject Matter: Capacitor colour code table, calculation of capacitance values using colour code, reading capacitor value from colour bands.

Specific Objectives

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

Cognitive Domain:

State the capacitor colour code table correctly.
Explain the steps involved in reading capacitor values from colour bands.
Calculate capacitance values using the colour code.

Affective Domain:

Appreciate the importance of colour coding in identifying capacitor values.
Show interest in practical applications of basic electricity.

Psychomotor Domain:

Draw the capacitor colour code table.
Accurately read the capacitance value from a given capacitor using its colour bands.

Collaborate with peers to interpret capacitor colour codes.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Basic Technology (Senior Secondary School).
State Unified Scheme of Work for Basic Electricity SSS 1.
Basic Electricity for Senior Secondary Schools by A.O. Okoro.
Online resources for electronic components colour codes.

Instructional Materials

The teacher will teach this lesson with the aid of:

Capacitor colour code chart.
Sample capacitors with visible colour bands.
Whiteboard and markers.

Rationale for the Lesson

This lesson helps pupils to understand how to identify the value of a capacitor, which is an important component in many electronic circuits. Being able to read colour codes enables pupils to select the correct capacitor for various applications in practical electronics.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of electricity, electronic components, and the function of a capacitor.

Lesson Content/Board Summary

CAPACITOR COLOUR CODING

Definition of Capacitor Colour Coding

Capacitor colour coding is a system used to indicate the capacitance value, tolerance, and sometimes the voltage rating of a capacitor using a series of coloured bands or dots.

Capacitor Colour Code Table

The capacitor colour code table assigns numerical values to different colours. This table is essential for decoding the capacitance value.

The standard colour code is:

Black – 0
Brown – 1
Red – 2
Orange – 3
Yellow – 4
Green – 5
Blue – 6
Violet – 7
Grey – 8
White – 9
Gold – Multiplier (x0.1), Tolerance (±5%)
Silver – Multiplier (x0.01), Tolerance (±10%)
No Colour – Tolerance (±20%)

Steps for Reading Capacitor Values Using Colour Bands

To read the capacitance value from colour bands, follow these steps:

Identify the first band, which represents the first significant digit.
Identify the second band, which represents the second significant digit.
Identify the third band, which represents the multiplier (power of ten).
Identify the fourth band, which represents the tolerance (percentage variation).
Some capacitors may have a fifth band for voltage rating or temperature coefficient.

Calculation of Capacitance Values

The capacitance value is calculated by combining the digits and multiplying by the multiplier. The unit of capacitance is Farad (F), often expressed in microfarads (µF) or nanofarads (nF).

Example: If a capacitor has colour bands: Red, Green, Orange, Gold.

Red = 2 (1st digit)
Green = 5 (2nd digit)
Orange = 3 (Multiplier = 10^3)
Gold = ±5% (Tolerance)

Value = 25 x 10^3 pF = 25,000 pF = 25 nF with ±5% 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 greets the pupils, reviews the previous lesson on types of capacitors, and introduces the topic by asking pupils how they would identify the value of different capacitors if the value is not printed clearly.
Pupils’ Activity: Pupils respond to questions and listen attentively.
Learning Point: Pupils recall previous knowledge and are introduced to the new topic.

Step 2: Presentation of Capacitor Colour Code Table

Time: 10 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher displays the capacitor colour code chart and guides pupils to draw the table in their notebooks. The teacher explains the numerical value assigned to each colour.
Pupils’ Activity: Pupils observe the chart, copy the table, and ask questions for clarification.
Learning Point: Pupils learn the standard capacitor colour code table.

Step 3: Explanation of Reading Values from Colour Bands

Time: 10 minutes
Teaching Skill: Demonstration
Teacher’s Activity: The teacher explains the significance of each colour band (first digit, second digit, multiplier, tolerance). Using a sample capacitor, the teacher demonstrates how to identify and read the values from the colour bands.
Pupils’ Activity: Pupils pay close attention to the explanation and demonstration, noting the steps.
Learning Point: Pupils understand the process of interpreting colour bands on a capacitor.

Step 4: Practical Reading Exercise

Time: 7 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher distributes sample capacitors to groups of pupils and asks them to identify the colour bands and attempt to read the values. The teacher moves around to provide guidance.
Pupils’ Activity: Pupils work in groups to identify colour bands on the provided capacitors.
Learning Point: Pupils gain practical experience in identifying capacitor colour codes.

Step 5: Calculation of Capacitance Values

Time: 5 minutes
Teaching Skill: Problem Solving
Teacher’s Activity: The teacher guides pupils through examples of calculating capacitance values from specific colour codes, writing the steps clearly on the board.
Pupils’ Activity: Pupils follow the examples, participate in calculations, and write down the solutions.
Learning Point: Pupils learn how to calculate capacitance values using the colour code formula.

Step 6: Class Activity/Practice

Time: 3 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher writes a few colour code combinations on the board and asks pupils to calculate the capacitance values individually or in pairs.
Pupils’ Activity: Pupils attempt to calculate the capacitance values.
Learning Point: Pupils reinforce their understanding through practice.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

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

What is capacitor colour coding?
State the colour code for the number 5 and the multiplier 10^4.
Explain how to read the capacitance value from a capacitor with four colour bands.
Calculate the capacitance value for a capacitor with the following colour bands: Brown, Black, Red, Silver.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 0 minutes
Teaching Skill: Closure
Teacher’s Activity: The teacher summarizes the main points of the lesson and assigns homework: “Draw the capacitor colour code table and find three different capacitors, then write down their colour codes and calculated values.”
Pupils’ Activity: Pupils listen to the summary and copy the homework.
Learning Point: Pupils consolidate their learning and are given tasks for further practice.

Lesson Keywords

Capacitor – An electronic component that stores electrical energy in an electric field.
Colour Code – A system using coloured bands to indicate component values.
Capacitance – The ability of a component to store an electrical charge, measured in Farads.
Multiplier – The factor by which the significant digits are multiplied.
Tolerance – The permissible variation in the actual value of a component from its stated value, expressed as a percentage.

Differentiation

For pupils who are struggling, the teacher will provide simplified colour code charts and extra worked examples. Advanced pupils will be challenged with capacitors having more bands (e.g., for voltage rating) or asked to research other capacitor marking systems.

Note for teachers using this lesson plan

Ensure that the sample capacitors have clearly visible colour bands. Encourage pupils to memorize the colour code table for quick identification. Emphasize the importance of correct orientation when reading the bands.