| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Physics |
| Lesson Topic: State that, for a parallel circuit, the current from the source is larger than the current in each branch |
Learning Objective/s:
- Describe why each branch of a parallel circuit experiences the full source voltage.
- Explain why the total source current is greater than the current in any single branch.
- Apply Ohm’s law and the parallel‑resistance formula to calculate total current.
- Compare series and parallel circuits in terms of current, voltage, and equivalent resistance.
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Materials Needed:
- Projector or interactive whiteboard
- Breadboard, three resistors (4 Ω, 6 Ω, 12 Ω), 9 V battery
- Multimeter
- Physics worksheet with practice questions
- Computer with PhET circuit simulation
- Calculator
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Introduction:
Begin with a quick discussion of household wiring and why appliances can run simultaneously. Recall students’ prior knowledge of series circuits and the concept of current flow. State that by the end of the lesson they will be able to demonstrate that the source current in a parallel circuit exceeds any branch current.
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Lesson Structure:
- Do‑now (5'): Students answer a short question on series‑circuit current (review).
- Mini‑lecture (10'): Present key concepts – equal voltage across branches, total current as sum of branch currents, resistance formula.
- Demonstration (10'): Build a 2‑branch parallel circuit on the breadboard; measure each branch current and the source current.
- Guided practice (15'): Use the PhET simulation to explore different resistor values; students record observations.
- Worked example (10'): Solve the 12 V, 6 Ω & 12 Ω example together, highlighting the algebraic sum.
- Independent practice (10'): Worksheet question on three resistors (4 Ω, 6 Ω, 12 Ω) with a 9 V source.
- Exit ticket (5'): Write one sentence explaining why the source current is larger than any branch current.
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Conclusion:
Summarize the relationship between source current and branch currents in parallel circuits and revisit the comparison with series circuits. Collect exit tickets to check understanding, and assign homework to calculate total current for a new set of parallel resistors using the formulas practiced today.
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