1. Topic 6 Refraction of Light Light has particle characteristics and behaves like waves. It is a member of the electromagnetic spectrum.

2. contents  Reflection of Light  Refraction of Light  Total Internal Reflection  Lenses  Chapter Review  Reflection of Light  Refraction of Light  Total Internal Reflection  Lenses  Chapter Review

3. refraction of light Exercise water air Incident ray water glass Incident ray air glass Incident ray

5. Ruler in water

6. Thermometer in water

7. total internal reflection For total internal reflection to occur  the light ray must travel from an optically denser medium towards a less dense medium  the angle of incidence must be greater than the critical angle For total internal reflection to occur  the light ray must travel from an optically denser medium towards a less dense medium  the angle of incidence must be greater than the critical angle total internal reflection Note: optically denser medium has a higher refractive index n

8. total internal reflection Exercise water air Incident rays critical angle c of water = 48.7° 41.3° 48.7° 40° 41.3° < c 48.7° 50° > c 50° Total internal reflection

9. total internal reflection n = sin c 1  relationship between refractive index and critical angle is

10. Optic fibre

11. Light enters the core (optically denser) and it reaches the cladding (less dense) at an  >critical angle c. Total internal reflection occurs. cladding core  

13. FIRBE OPTICS 1.Installation of optical fibre at HDB flat http://www.youtube.com/watch?v=Bq6GSMrdqfE 2. Next Generation Nationwide Broadband Network http://www.youtube.com/watch?v=_-CohUnEcn4