1Refraction
The bending of light as it passes from one medium to another
2*when light travels medium to medium, refracted towards or away from normal?
*When light travels from a rarer
to a denser medium it is
refracted towards the normal
When light travels from a
denser to a rarer medium it is
refracted away from the
3The Laws of Refraction of Light
1) The incident ray, the normal and the refracted ray all lie in the same plane.
2) The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant
.
i.e. n = Sin i ÷ Sin r , where n is a constant
4Refractive Index of a Medium/Substance
The Refractive Index of a Medium is the ratio of the sine of the angle of incidence to the sine of the angle of refraction when light travels from a vacuum into that medium.
(if substance, medium= substance)
5Refractive Index between Two Media
The refractive index between two media is the ratio of the sine of the angle of incidence to the sine of the angle of refraction when light travels from one of those media into the other.
6Critical Angle
When light travels from a denser to a rarer medium the angle of incidence whose corresponding angle of refraction is 90° is called the critical angle for those two media.
7Total Internal Reflection
Occurs when the angle of incidence in the denser medium exceeds the critical angle and all the light is reflected back into the medium.
8Optical Fibre
A very thin transparent rod through which light can
travel by total internal reflection