Refraction Flashcards
what is refraction?
the change in light speed from one medium to another
refractive index
measures the effect a medium has on light
greater refractive index means..
the angle of refraction will be smaller in the medium
value of refractive index
always greater than or equal to 1
refractive index equation
n=sin theta a / sin theta m
refractive index equation for velocity and wavenlength
n = va/vm = lambda a / lambda m
what happens to frequency of light in medium
DOES NOT CHANGE inside medium
what does refractive index depend on
frequency of light (why white light seperates into rainbow when passing through prism)
each colour refracts differently
do short or long wavelengths refract more?
short
do short or long wavelengths diffract more?
long
what is the critical angle?
the angle at which light no longer refracts and instead travels along the edge of the prism
angle of incidence at which angle of refraction is 90 degrees
critical angle equation
n = 1 / sin theta c
total internal reflection
when all light is reflected back inside the block and none of it is refracted
theta < theta c
refracts
more dense to less dense medium
tends away from normal