IG Phy – Total Internal Reflection and The Critical Angle

When light travels from glass to air, it speeds up and refracts towards the normal.

The angle of incidence is equal to the angle of reflection.

The critical angle is the angle of incidence when the angle of refraction is 90°.

Total internal reflection occurs when the angle of incidence is less than the critical angle.

Total internal reflection can only occur when light travels from a medium with a lower refractive index to a higher refractive index.

The critical angle for glass is about 42°.

Total internal reflection is used in optical fiber cables.

An optical fiber can channel light even when it is bent.

Light entering one end of the fiber undergoes repeated internal reflections as it travels along the length of the fiber.

The refractive index of a material can be calculated using the formula n=sinc1​.

Prisms provide multiple and blurred images unlike glass mirrors.

A bicycle reflector uses total internal reflection to reflect light back towards its source.

Total internal reflection cannot be demonstrated using a semi-circular glass block.

Optical fibers are more expensive than traditional copper cables and can carry fewer signals.