C.3.4—Total internal reflection Topic Practice
C.3.4—Total internal reflection Topic Practice
Practise deciding when total internal reflection occurs by using critical-angle equations, refractive-index data, and prism or fibre ray diagrams.
How this is tested
- calculate the critical angle from refractive index or speed data, then compare it with the incident angle
- use a prism or fibre ray diagram to decide whether a ray emerges or undergoes total internal reflection
- state the design choice that cladding has slightly lower n than the core to keep rays trapped in a fibre