IGCSE Physics: The Doppler Effect | Edexcel Modular | Unit 5 | L4

IGCSE Physics: The Doppler Effect | Edexcel Modular | Unit 5 | L4

This lesson covers spec point 5.8 — explaining the change in observed frequency and wavelength when a source moves relative to an observer (the Doppler Effect). Entirely qualitative — no calculations required at IGCSE.

PowerPoint includes:
• Retrieval starter reviewing wave speed and frequency
• Direct Instruction (I Do) — Doppler Effect defined; wavefront compression and stretching explained; stationary vs moving source comparison
• Guided Practice (We Do) — three real-world scenarios: approaching train, stationary source, departing train
• Independent Practice (You Do) — buzzer on a string exam question; wavefront sketch activity; racing car sequencing task
• Misconception check: does wave speed change? (true/false with reasoning reveal)
• Real-world discussion: mobile phone frequency bands
• Review and Reflect exit ticket on observed wavelength

Activity Sheet includes:
• 10 questions plus stretch — entirely qualitative, matching spec requirements
• Questions covering approaching, receding, stationary and relative motion scenarios
• Q8 includes a wavefront sketch task
• Q10 targets the relative motion misconception (observer moving with source)
• Stretch question uses racing car sequencing activity from the lesson
• Full mark scheme for teacher use