1. Refraction

2. Reflection & Refraction

3. Refraction

4. Air – lower refractive index Water – higher refractive index The Kingfisher When light is passing from a higher refractive substance into a lower refractive substance the light rays bend away from the perpendicular to the surface. perpendicular Refraction

5. Air – lower refractive index Water – higher refractive index The Fish When light is passing from a lower refractive substance into a higher refractive substance the light rays bend toward the perpendicular to the surface. perpendicular Refraction

6. Air – lower refractive index Glass – higher refractive index Glass Window Air – lower refractive index Refraction Light passing through a transparent material exits at the same angle it enters

7. Lens Application Refraction

8. Total Internal Reflection Can occur when light inside glass block hits the edge at certain angles As you increase the angle the ray gets bent However – at a particular angle called the Critical Angle something strange happens

9. TOTAL INTERNAL REFLECTION OF LIGHT N INCIDENT RAY REFRACTED RAY The ray is refracted parallel to the edge of the block at the Critical angle

10. As we increase the angle of incidence As the angle of incidence increases, the ray is now only reflected back inside the block The edge of the block acts like a mirror The ray does not pass out of the block This is total internal reflection

11. So the 60 0 angle has total internal reflection

12. Internal Reflection This occurs only when light travels from more dense to less dense media.

13. Appplications Fibre optics – Communication – Lighting – Endoscopy