Reflection & Refraction

Views:
 
Category: Education
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

Slide 1:

The King David High School Science Department Reflection and Refraction By Mr Jones

Reflection:

Reflection For light reflecting off a plane mirror (flat, smooth, shiny): Mirror Incident Ray Reflected Ray Normal Angle of reflection (r) r i The normal is a line drawn at right angles (perpendicular) to the surface. Angle of incidence ( i ) =

Reflection:

Reflection For light reflecting off a plane mirror (flat, smooth, shiny): Mirror Angle of reflection (r) Angle of incidence ( i ) =

Refraction:

Refraction Air Perspex Incident Ray Emergent Ray Normal Normal Refracted Ray

Refraction:

Refraction As light passes from a less optically dense material into a more optically dense material it moves towards the normal. As light passes from a more optically dense material into a less optically dense material it moves away from the normal. Less optically dense More optically dense Incident Ray Normal Less optically dense More optically dense Emergent Ray Normal

Total Internal Reflection:

Total Internal Reflection Incident Ray Refracted Ray Reflected Ray When the angle of incidence is small (less than 42°) most of the light emerges from the Perspex and is refracted away from the normal. A tiny amount of light is reflected at the interface. i <42°

Total Internal Reflection:

Total Internal Reflection Incident Ray When the angle of incidence is 42° most of the light is refracted at 90° from the normal (along the interface). Some light is reflected at the interface. 42° is described as the critical angle. 42° 90°

Total Internal Reflection:

Total Internal Reflection Incident Ray Reflected Ray When the angle of incidence is greater than 42° no refraction takes place. All of the light is reflected. This is known as total internal reflection. i >42°

Total Internal Reflection:

Total Internal Reflection