| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Physics |
| Lesson Topic: Describe the pattern and direction of the magnetic field due to currents in straight wires and in solenoids |
Learning Objective/s:
- Describe the circular magnetic field pattern around a straight current‑carrying wire and the uniform field inside a long solenoid.
- Apply the right‑hand thumb rule and right‑hand grip rule to determine magnetic field direction for wires and solenoids.
- Calculate magnetic field strength using B = μ₀I/2πr for a straight wire and B = μ₀nI for a solenoid.
- Compare how field strength varies with distance for a straight wire versus a solenoid.
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Materials Needed:
- Projector or interactive whiteboard
- PowerPoint/Google Slides presentation
- Printed diagram handouts of right‑hand rules
- Simple circuit kits (straight wire, battery, ammeter)
- Solenoid model or coil
- Worksheet with practice calculations
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Introduction:
Begin with a quick demonstration: switch on a current through a straight wire and show a compass deflection to spark curiosity. Ask students what they already know about magnetic fields around currents and set the success criteria: they will be able to sketch field patterns, use right‑hand rules, and perform basic calculations.
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Lesson Structure:
- Do‑now (5'): Students answer a short recall question on magnetic field lines from a previous lesson.
- Mini‑lecture (10'): Explain the circular field around a straight wire, introduce the right‑hand thumb rule, and derive B = μ₀I/2πr.
- Hands‑on demo (10'): Use the circuit kit and a compass to observe the field direction; students practice the thumb rule.
- Mini‑lecture (10'): Present the solenoid, right‑hand grip rule, and B = μ₀nI; show diagrams of uniform interior field.
- Group activity (15'): Teams calculate magnetic fields for given wire and solenoid problems on the worksheet; teacher circulates for feedback.
- Concept‑check (5'): Quick quiz (exit ticket) with one question on each rule and one calculation.
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Conclusion:
Summarise the key differences between the magnetic fields of straight wires and solenoids and revisit the right‑hand rules. Collect the exit tickets to gauge understanding, and assign a homework task: solve two additional calculation problems and write a short explanation of how the right‑hand rule would be applied to a coil of wire.
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