4.5 Total Internal Reflection

Question 1

What is total internal reflection?

Answer 1

A specific case of refraction in which the ray moves form a medium of higher refract index to one of a lower refractive index. In this case the refracted ray bends away from the normal.

Question 2

What happens when the angle of incidence is increased?

Answer 2

Angle of refraction also increases eventually become 90 degrees.

Question 3

What is the angle of incidence called when the angle of refraction equals 90 degrees?

Answer 3

The critical angle.

Question 4

What happens when the angle of incidence is greater than the critical angle?

Answer 4

No refraction takes place the ray refracts back not the medium from where it came.

Question 5

How can the critical angle be found from Snell’s law?

Answer 5

n1sin@C = n2sin90

or

sin@C = n2/n1