Lesson Notes By Weeks and Term v4 - SHS 1
POWERING THE FUTURE WITH ENERGY FORMS
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
POWERING THE FUTURE WITH ENERGY FORMS
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: General Science
Class: SHS 1
Term: 1st Term
Week: 19
Grade code: 2.3.1.LI.2
Strand code: 3
Sub-strand code: 1
Content standard code: 2.3.1.CS.1
Indicator code: 2.3.1.LI.2
Theme: VIGOUR BEHIND LIFE
Subtheme: POWERING THE FUTURE WITH ENERGY FORMS
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
Welcome, students! Every day, we see large metal boxes on electricity poles in our communities, from the busiest streets of Accra to quiet villages. We hear them humming. These are transformers. We also use smaller versions of them every time we charge our phones or laptops. But what do they do, and how do they work? This lesson will demystify the transformer. Understanding transformers is crucial because they are the backbone of how the Electricity Company of Ghana (ECG) gets power from the Akosombo Dam to our homes safely and efficiently. By the end of this lesson, you will understand the magic behind these essential devices that power our modern lives.
2.1 What is a Transformer?
A transformer is a static electrical device that transfers electrical energy from one circuit to another through electromagnetic induction. Its primary function is to increase (step-up) or decrease (step-down) the voltage of an alternating current (AC) supply without changing its frequency.
Key Point: Transformers ONLY work with Alternating Current (AC). They do not work with Direct Current (DC) from sources like a dry cell battery. This is because their operation depends on a *changing* magnetic field. 2.2 Components of a Simple Transformer
A simple transformer has three main parts: Primary Coil: The coil of insulated wire that is connected to the input AC voltage source. Secondary Coil: The coil of insulated wire where the output voltage is induced. Soft Iron Core: A core made of laminated (layered) soft iron sheets. Its purpose is to concentrate the magnetic field lines, ensuring that almost all the magnetic flux created by the primary coil links with the secondary coil. The core is laminated to reduce energy loss due to *eddy currents*. 2.3 The Principle of Operation: Mutual Induction