By Team Aakash Byju's
When a light ray moves from a denser medium to a rarer medium, it deviates from the average at a refracted angle r.
As the angle of incidence increases, it moves further away from normal and the angle of refraction decreases.
By increasing the angle of incidence, the angle of refraction will become equal to 90 degrees, and a further increase in angle results in reflection.
The angle of incidence should correspond to the angle of refraction which is known as the Critical angle.
For the total internal reflection to occur, the angle of incidence must be greater than the critical angle.
Snell's law governs the formula for total internal reflection, which is formulated as: