P1 - Wave Properties Flashcards
(13 cards)
What happens when a waves meet a new material or an obstacle?
It’s direction can be changed.
How do waves travel?
In straight lines.
What 3 things cause a wave to change its direction?
Refraction, diffraction, reflection.
What happens if light is reflected on a clear angle?
You get a clear reflection because all the light is reflected at the same angle.
What is the law of reflection?
Angles of INCIDENCE = angles of REFLECTION
Where is the angle of incidence?
In between the incidence ray and the normal.
Where is the angle of reflection?
In between the reflected light ray and the normal
What is the normal?
It’s an imaginary like that is perpendicular (90 degrees) to the surface.
What does total internal reflection depend on?
The critical angle.
What conditions can total internal reflection only happen in?
When it is travelling from a dense material like glass, water or Perspex towards a less dense substance like air.
What happens if the angle of incidence is bigger than the critical angle?
It’s all internally reflected known as - total internal reflection.
What happens if the angle of incidence is equal to the critical angle?
The light ray would go along the surface with some internal reflection.
What happens if the angle of incidence is smaller than the critical angle?
Most of the light is refracted, but some of it is internal reflected.
