P3 - Refractive Index Flashcards
1
Q
What is refraction caused by?
A
A change of medium density so a change in speed.
2
Q
What is refraction?
A
When waves change direction as they enter a different medium.
3
Q
What happens when waves slow down?
A
They bend towards the normal.
4
Q
What happens when light enters glass or plastic?
A
It slows down to 2/3 of its speed in air.
5
Q
What happens if a wave hits a boundary at 90 degrees (along the normal for example)?
A
It will not change direction.
6
Q
What is the angle of incidence?
A
The angle at which the light hits the medium.
7
Q
What is the refractive index?
A
The ratio of speed of light in a vacuum to speed of light in that medium.
8
Q
What is the equation for refractive index (n)?
A
Refractive index (n) = sin i / sin r.
