Lesson Notes By Weeks and Term v4 - SHS 1
POWERING THE FUTURE WITH ENERGY FORMS
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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: 18
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
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In Ghana, we all depend on electricity from the national grid, powered by sources like the Akosombo and Bui dams. But how does this electricity travel hundreds of kilometres from the Volta Region to our homes in Accra, Kumasi, or Tamale and safely power our phones, lights, and televisions? The answer lies in a simple but powerful device called a transformer. This lesson will demystify the transformer, explaining how it works, its different types, and why it is the unsung hero of our electrical world. Understanding transformers is key to understanding how we power our future.
A. What is a Transformer?
A transformer is an electrical device that transfers electrical energy from one alternating current (AC) circuit to another, without a direct electrical connection. Its main purpose is to change the voltage and current levels.
Crucial Point: Transformers ONLY work with Alternating Current (AC). They do not work with Direct Current (DC) from batteries because the working principle requires a *changing* magnetic field. A steady DC current creates a steady, unchanging magnetic field, which cannot induce a voltage in the second coil. B. The Principle of Operation: Mutual Electromagnetic Induction
The transformer works on a principle called mutual electromagnetic induction. This sounds complex, but it can be broken down into four simple steps: Input: An alternating voltage is applied to the first coil, called the primary coil. This causes an alternating current to flow through it. Magnetic Field Creation: This alternating current produces a continuously changing magnetic field in and around the primary coil. Field Concentration: The soft iron core is used to concentrate this changing magnetic field and guide it to pass through the second coil, called the secondary coil. Output (Induction): As the changing magnetic field lines "cut" through the wires of the secondary coil, they induce an alternating voltage (or e.m.f.) across the ends of the secondary coil. This is Faraday's Law of Induction in action.