This memory aid covers Memory Aid within Reflection & Refraction for GCSE Physics. Revise Reflection & Refraction in Waves for GCSE Physics with 15 exam-style questions and 15 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 9 of 13 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
🧠 Memory Aid
Refraction direction: "Slow to Fast — bend away from normal. Fast to Slow — bend toward normal."
Or remember it with a speed analogy: entering a denser medium is like a car going from tarmac into mud. The car slows and turns toward the mud (toward the normal). Coming back out of mud onto tarmac, it speeds up and swings away.
Critical angle conditions — the "DANG" rule:
- Denser medium (light must be in the denser material)
- Angle is greater than critical angle
- No refraction occurs
- Goes back by total reflection
Practice questions for Reflection & Refraction
According to the law of reflection, the angle of incidence is:
Explain why a ray of light bends when it passes from air into water.