Revise GCSE Physics

Question:What is Total Internal Reflection?

When a wave arrives at the interface between a more dense medium (like glass) and a less dense medium (like air) something unexpected can happen.

The diagram shows what happens if we increase the angle of incidence at which a ray of light arrives at a glass to air interface.

So, if the angle of incidence is greater than a value called the critical angle, then no refraction occurs and instead all of the light is reflected.

Angry face