Refraction Flashcards
What is refraction?
the way a wave changes direction as it enters a different medium
What happens when we enter a more optically dense material?
The wave will slow down and bend towards the normal
What happens when we enter a less optically dense material
The wave will speed up and bend away from the normal
this means wavelength must increase
What wave property doesn’t change during refraction?
frequency
What 2 properties do change?
the wavelength and wave speed - these both decrease or increase
What are the 2 rules of refraction?
- both rays lie in a plane perpendicular to surface
- snell’s law
what is the refractive index?
a ratio between speed of light in a vacuum and in that material . it is always greater than 0.
equation for the refractive index?
n = c/v n = λ1/λ2 n = v1/v2
What does a greater refractive index mean?
a more optically dense material
What is snell’s law?
n1 sin x1 = n2 sinx2
it is the ration of angles of incidence and refraction
What is the name of the ray approaching the interface/boundry?
incidence ray
What is the name of the ray within the new medium?
refracted ray
what is the refractive index of the air?
n = 1
What does using a larger angle mean in terms of precision of measurements?
a more precise measurements as uncertainty is reduced, as a certain percentage leads to a smaller value
a graph of sinx1 against sinx2 gives a gradient of what if one of the mediums is air/
the refractive index
