Lesson Plan

• Describe the transverse nature of electromagnetic waves.
• Explain why every EM wave propagates at the same speed c in free space.
• Compare the different regions of the electromagnetic spectrum while recognising the common wave properties.
• Apply the relation c = 1/√(μ₀ε₀) to confirm the universal speed of light.

• Projector or interactive whiteboard
• Slide deck with wave diagrams and spectrum chart
• Printed worksheet containing vector‑diagram tasks
• Laser pointer or simulation software (e.g., PhET) to show polarization
• Scientific calculators
• Exit‑ticket slips

Begin with a quick visual of a rainbow and ask students what all the colours have in common. Link this to their prior knowledge of light as an EM wave and state the success criteria: students will identify the transverse nature of EM waves and justify the constant speed c.

1. Do‑now (5 '): short quiz on previous wave concepts.
2. Mini‑lecture (10 '): introduce transverse fields and the constants μ₀, ε₀; derive c = 1/√(μ₀ε₀).
3. Demonstration (10 '): use a laser & polariser or a simulation to visualise perpendicular E and B fields.
4. Guided worksheet (15 '): students label E‑field, B‑field, and propagation direction for several spectrum regions.
5. Check for understanding (5 '): concept questions using clickers or show of hands.
6. Summary discussion (5 '): reinforce that all EM waves share the same transverse nature and speed.

Recap the three key points: transverse fields, universal speed c, and the spectrum’s breadth. Students complete an exit ticket stating one real‑world example of an EM wave and why it still travels at c. For homework, assign a brief research task on a technology that relies on a specific part of the electromagnetic spectrum.