PHYSICS - WAVES - Refraction

Refraction

Bending of light or other waves as it passes from 1 medium to another due to a change in its speed

change in speed causes light ray to bend at the boundary between the 2 media

incident ray

ray of light that approaches the boundary between 2 media

refracted ray

ray of light that bends as it passes into the 2nd medium

normal

imaginary line perpendicular to the boundary at the point where the light ray hits the surface

angle of incidence(i)

angle between incident ray and normal

angle of refraction(r

angle between refracted ray and normal

refractive index (n)

measure of how much a material slows down light

n = v¹/v² = sini/sinr

v¹ = speed of light in first medium

v² = speed of light in second medium

laws of refraction

1.incident ray, refracted ray, and normal lie in the same plane

2.ratio of sini and sinr is contant

effect of refraction

1.towards the normal - when light enters a denser medium, it slows down and bends towards the normal

2.away from normal - when light enters a less dense medium, it speeds up and bends away from the normal

refractive index (n)

measure of how much light slows down when entering a medium

v = speed of light in vacuum (c) / speed of light in medium (v)

snell’s law

describes how light bends when moving between 2 different media

n¹sini = n²sinr

n¹ = refractive index of first medium

n² = refractive index of second medium