Lesson Plan

• Describe magnetic flux and its relationship to magnetic field strength and area.
• Apply Φ = B A cosθ to calculate flux for perpendicular and angled fields.
• Convert units correctly and identify common errors in flux calculations.
• Solve practice problems involving rectangular and circular loops.
• Explain how the angle θ influences flux and justify the use of the cosine factor.

• Projector or interactive whiteboard
• Slide deck with formulas and diagrams
• Worksheet with practice problems
• Rulers and calculators
• Magnetic‑field simulation app (optional)
• Whiteboard markers

Begin with a quick question: “How does a bicycle dynamo light a bulb as you ride?” Connect this to magnetic flux and the idea that changing magnetic fields generate electricity. Review that students already know about magnetic fields (B) and area (A). State that by the end of the lesson they will be able to calculate flux accurately and spot typical mistakes.

1. Do‑Now (5'): Students answer a short prompt on everyday devices that rely on magnetic fields.
2. Mini‑lecture (10'): Review definitions, derive Φ = B A cosθ, and illustrate with a diagram on the projector.
3. Guided example (8'): Work through the square‑loop calculation together, emphasizing unit consistency.
4. Collaborative problem solving (12'): Pairs solve the three practice problems; teacher circulates to check reasoning.
5. Common mistakes discussion (5'): Highlight unit mix‑ups, ignoring θ, and area errors; students correct a deliberately flawed example.
6. Exit ticket (5'): Each student writes one correct flux calculation and one mistake to avoid.

Summarise that magnetic flux depends on field strength, area, and the angle between them, and that consistent SI units are essential. Collect exit tickets to gauge understanding, and assign the worksheet for homework to reinforce the calculations.