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Subject: Physics
Semester: 2
Period: 5
Week: 29
School Name:
Teacher’s Name:
Subject: Physics
Grade Level: Grade 10
Week & Period: Week 29, Period V
Date:
Sub-topic: Capacitors and Capacitance
Learning Objectives: By the end of the lesson, learners should be able to:
- Define a capacitor and capacitance.
- State the unit of capacitance.
- Identify and describe the different types of capacitors and their uses.
- Explain the charging and discharging of a capacitor.
- Solve problems involving capacitance, charge, and potential difference using:
C = Q / V
Instructional Materials:
- Physical capacitors (electrolytic, ceramic, paper)
- Digital multimeter
- Chart of types and symbols of capacitors
- Power supply, connecting wires
- Light bulb, stopwatch (for discharge demo)
- Worksheets with numerical problems
Anticipation (Warm-Up): Pose a question: "Why do some devices still light up after being unplugged?" Introduce capacitors as charge-storage components responsible for this behavior.
Building Knowledge:
- Capacitor: A device that stores electrical energy in an electric field.
- Capacitance (C): Ability of a capacitor to store charge per volt applied. Formula: C = Q / V (Unit: Farad, F)
- Types of Capacitors: Electrolytic, ceramic, mica, polyester – classified by materials and structure.
- Charging a Capacitor: Electrons accumulate on one plate, creating an electric field.
- Discharging a Capacitor: The stored charge is released across a circuit, often quickly.
Example Calculation 1: A capacitor of 10 µF holds a charge of 0.002 C. What is the potential difference? V = Q / C = 0.002 / (10 × 10⁻⁶) = 200 V
Example Calculation 2: Find the charge stored in a 5 µF capacitor connected across 12 V. Q = C × V = 5 × 10⁻⁶ × 12 = 6.0 × 10⁻⁵ C
Activities:
- Match real capacitor types with images and applications.
- Solve 3 problems involving C = Q/V.
- Label diagrams of capacitors showing charging/discharging.
Experiment: Objective: Observe charging/discharging.
Materials: Capacitor (470 µF), battery (9 V), bulb, stopwatch, wires. Procedure:
- Connect the capacitor in series with the bulb and battery.
- Observe bulb brightness during charge.
- Disconnect battery and observe bulb glow during discharge.
Observation: Bulb dims as capacitor discharges.
Conclusion: Capacitor stores and releases energy over time.
Assessment:
- Define capacitance and state its unit.
- What type of capacitor is commonly polarized?
- A 50 µF capacitor holds 0.01 C. What is the voltage?
- Describe the process of charging a capacitor.
Homework:
- Draw symbols for 3 types of capacitors.
- Calculate the charge on a 22 µF capacitor charged to 5 V.
Expanded Notes:
- Capacitors are vital in power supplies, filters, and timing circuits.
- Capacitance depends on plate area, distance, and dielectric material.
- High voltage capacitors can be dangerous when charged.
Differentiation:
- Real object identification for tactile learners.
- Stepwise calculations for visual learners.
- Group demonstrations for peer support.
Teacher’s Reflection:
- Did learners understand charging vs. discharging?
- Were formula applications clear?
- Should we spend more time on experiment interpretation?