refraction Flashcards
define refraction
bending or change in direction of light when it travels from one medium into another
which way does light bend when it travels into a medium that slows the speed of light
towards the normal
which way does light refract when it travels into a medium that speeds its pace
away from the mirror
what is the index of refraction
ratio of speed of light in a vacuum to the speed of light in a medium
what does Snell’s law show
relationship between angles of incidence and refraction
what are the rules for refraction
1) incident ray, the normal, and refracted ray all lie on the same plane
2) light bends toward the normal when the speed of light in the second medium is less than the speed of light in the first medium
what is the equation for the index of refraction
n= c/v
what does each variable mean in the index of refraction equation
n = index of refraction
c = speed of light in vacuum
v = speed of light in a given medium
what is a critical angle
the angle of incidence that results in an angle of refraction of 90 degrees
when does total internal refraction occur
occurs when the angle of incidence is greater than the critical angle
what conditions must be present for total internal reflection to occur
1) the light is travelling slower in the first medium than the second
2) the angle of incidence is large enough that no refraction occurs in the second medium
what is fibre optics
technology that uses light to transmit information along a glass cable
