Revise GCSE Physics

Question:Why is it called Total Internal Reflection?

It is called Total internal reflection because there is always a small reflection when a wave travels from one medium to another.

When light passes through ordinary glass, there is a 4% reflection from both sides of the glass. This is why you can see your reflection in a glass window.

It is called internal reflection because it happens inside of a material.

Total internal reflection is often shortened to TIR.