11.8+ 11.9 Refractive index+ total internal reflection Flashcards
1
Q
What is refractive index?
A
How much it slows down
2
Q
What is Snells Law?
A
3
Q
What happens to the angle of incidence / refraction when moving from one medium to another?
A
4
Q
Define total internal reflection
A
The reflection of all light back into the original medium when hitting a boundary between two media;
* the original medium will have a higher refractive index (n1>n2)
* the incidence angle at the boundary must be greater than the critical angle
5
Q
Define critical angle
A
The angle of incidence at the boundary between 2 media, that will produce an angle of refraction of 90°
6
Q
What is the critical angle ?
A
7
Q
What is the formula for the critical angle?
A
8
Q
What happens in fibre optic cables ?
A
Total internal reflection
9
Q
Does refractive index vary with frequency?
A
