Lesson Notes By Weeks and Term v4 - SHS 3
ELECTROMAGNETIC INDUCTION & APPLICATIONS
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ELECTROMAGNETIC INDUCTION & APPLICATIONS
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Physics
Class: SHS 3
Term: 2nd Term
Week: 10
Grade code: 3.3.3.LI.3
Strand code: 3
Sub-strand code: 3
Content standard code: 3.3.3.CS.1
Indicator code: 3.3.3.LI.3
Theme: ELECTRIC FIELD, MAGNETIC FIELD AND ELECTRONICS
Subtheme: ELECTROMAGNETIC INDUCTION & APPLICATIONS
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Good day, learners. Today, we are going to unravel one of the most important principles in all of physics, a principle that powers our homes, charges our phones, and runs our industries. Think about the Akosombo Dam. It generates massive amounts of electricity for Ghana without burning any fuel. How does it do this? Or consider a simple bicycle light that turns on when you pedal, with no batteries. The magic behind these phenomena is Electromagnetic Induction. It is the link between magnetism and electricity. Understanding this principle is key to understanding how our modern world is powered.
A. What is Electromagnetic Induction?
In our previous lessons, we learned that an electric current can produce a magnetic field (electromagnetism). The big question scientists like Michael Faraday asked was: can the reverse happen? Can a magnetic field produce an electric current? The answer is YES, but with a condition.
Electromagnetic Induction is the process of generating an electromotive force (e.m.f.) and hence a current in a conductor, by changing the magnetic field around it.
An e.m.f. is like a "voltage" or an "electrical pressure" that can push charges around a circuit to create a current. The e.m.f. is induced (created) only when the magnetic field through the conductor is *changing*. A stationary magnet next to a stationary wire does nothing. There must be relative motion or a change in field strength. B. Magnetic Flux (Φ)