WavesTopic Summary
Topic Summary: Reflection and Refraction
Part of Reflection & Refraction — GCSE Physics
This topic summary covers Topic Summary: Reflection and Refraction within Reflection & Refraction for GCSE Physics. Revise Reflection & Refraction in Waves for GCSE Physics with 15 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 13 of 13 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 13 of 13
Practice
15 questions
Recall
15 flashcards
Topic Summary: Reflection and Refraction
Key Terms
- Normal: perpendicular line to surface at point of contact
- Specular: reflection from smooth surface → clear image
- Diffuse: reflection from rough surface → scattered rays
- Critical angle: angle beyond which TIR occurs
- TIR: total internal reflection when angle > critical angle
Key Rules
- i = r (law of reflection)
- Fast to slow → bends toward normal
- Slow to fast → bends away from normal
- TIR: denser medium + angle > critical angle
- Hit at 90° → no bending, but speed changes
TIR Applications
- Optical fibres (data transmission)
- Endoscopes (medical imaging)
- Diamonds (sparkle)
- Binoculars / periscope prisms
Exam Tips
- Always draw the normal first in ray diagrams
- Angles measured from normal, not surface
- State BOTH TIR conditions for full marks
- "Slow to fast bends AWAY" — away = opposite to where it came from