Total internal reflection

The video tutorial explains the concept of total internal reflection, which occurs when the angle of incidence exceeds the critical angle, causing light to be completely reflected within a material. For glass, this critical angle is approximately 42°. This principle is utilized in fibre optic cables to transmit information efficiently over long distances without loss.

What is the condition for total internal reflection to occur?

• The angle of incidence must be zero.

• The angle of incidence must be greater than the critical angle.

• The angle of incidence must be equal to the critical angle.

• The angle of incidence must be less than the critical angle.

What is the approximate critical angle for glass?

• 90 degrees

• 30 degrees

• 42 degrees

• 60 degrees

What happens to light when the angle of incidence exceeds the critical angle?

• It is absorbed by the material.

• It stops traveling.

• It is refracted out of the material.

• It is completely reflected within the material.

How do fiber optic cables use total internal reflection?

• To transmit information in the form of light.

• To transmit sound waves.

• To absorb light and convert it to heat.

• To reflect sound waves.

Why is total internal reflection beneficial for fiber optic cables?

• It increases the speed of sound transmission.

• It allows light to escape the cable.

• It reduces the cost of the cables.

• It prevents loss of information over long distances.