Lesson Notes By Weeks and Term v4 - SHS 2
ELECTROMAGNETISM
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
ELECTROMAGNETISM
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Physics
Class: SHS 2
Term: 2nd Term
Week: 6
Grade code: 2.3.1.LI.5
Strand code: 3
Sub-strand code: 2
Content standard code: 2.3.1.CS.2
Indicator code: 2.3.1.LI.5
Theme: ELECTRIC FIELD, MAGNETIC FIELD AND ELECTRONICS
Subtheme: ELECTROMAGNETISM
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! Today, we are exploring a very important component in almost every electronic device you use: the capacitor. Think about your phone charger, the flash on a camera, or the backup power systems (UPS) many homes and offices use during "dumsor" (power outages). These devices rely on the ability of capacitors to store and release electrical energy quickly. A capacitor acts like a small, super-fast rechargeable battery. Understanding how they store energy is fundamental to understanding how modern electronics work. This knowledge is not just for exams; it helps us appreciate the technology that shapes our daily lives in Ghana.
2.1 What is a Capacitor?
A capacitor is an electronic component that stores electrical energy in an electric field. In its simplest form, it consists of two parallel metal plates separated by an insulating material called a dielectric. The dielectric can be air, paper, ceramic, or plastic. Symbol: The circuit symbol for a capacitor is: `---||---` 2.2 Capacitance (C)
Capacitance is the measure of a capacitor's ability to store electric charge. It is defined as the ratio of the magnitude of the charge (Q) on one of the plates to the potential difference (V) between the plates. Formula: `C = Q / V` Units: The SI unit of capacitance is the Farad (F), named after Michael Faraday.
One Farad is a very large unit of capacitance. In practice, we use smaller units: microfarad (μF): 1 μF = 10⁻⁶ F nanofarad (nF): 1 nF = 10⁻⁹ F picofarad (pF): 1 pF = 10⁻¹² F 2.3 How a Capacitor Stores Energy