Introduction Refraction of light at a boundary Experimental results Refractive index Refractive index of glass Experiment results Reversibility of light Critical angle Total internal reflection Absolute refractive index Questions
 
David Atkinson, Hugh Baird College
Paul Berry, MATTER Project
Introducing the concept of refraction of light when it crosses a boundary
separating two transparent media.
Learning outcomes
After completing this section you should be able to:
 draw the correct path of a ray of light when it crosses a boundary between two media of
different densities; 
 mark on a diagram the angles of incidence and refraction as well as the normal to the
boundary at the point of incidence; 
 state Snell's Law; 
 define the absolute refractive index of a material; 
 state the conditions necessary for total internal reflection to take place; 
 calculate the critical angle for a given pair of media given their absolute refractive
indices. 
Assumed prior knowledge
It is assumed that you have knowledge of the following concepts:
 the measurement of angles in degrees; 
 the meaning of the natural sine (sin) of an angle between 0° and 90°; 
 calculation of the gradient of a straight line graph. 
