Lesson Notes By Weeks and Term v4 - SHS 3
ATOMIC PHYSICS
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ATOMIC PHYSICS
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Subject: Physics
Class: SHS 3
Term: 2nd Term
Week: 17
Grade code: 3.3.4.LI.2
Strand code: 4
Sub-strand code: 1
Content standard code: 3.3.4.CS.3
Indicator code: 3.3.4.LI.2
Theme: ATOMIC AND NUCLEAR PHYSICS
Subtheme: ATOMIC PHYSICS
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Welcome, future engineers and scientists! Today, we are exploring a fascinating part of Atomic Physics that powers our daily lives. Look at the mobile phone in your pocket or the laptop you use. How do you charge them? You use a charger that you plug into the wall socket. But the electricity from the wall (AC) is very different from the electricity your battery needs (DC). The device that makes this change possible – the charger – works because of principles rooted deep in Atomic Physics. In this lesson, we will "look inside" a battery charger and understand the atomic science that makes it work.
Part 1: The Problem - AC vs. DC
Our homes, schools, and offices are supplied with Alternating Current (AC) from the Electricity Company of Ghana (ECG). In AC, the direction of the current flows back and forth rapidly (50 times per second, or 50 Hz).
However, electronic devices like phones, laptops, and rechargeable lamps use batteries. Batteries store and supply Direct Current (DC), where the current flows in only one direction.
The Challenge: How do we use AC from the wall to charge a DC battery? The Solution: We need a device to convert AC into DC. This process is called rectification, and the core of the device that does this is a rectifier, found inside every battery charger.