Refraction

Question 1

what is the content in this lesson

Answer 1

This lesson focuses on refraction, speed of light and its relationship to refractive index. We will find that although the speed of light in a vacuum is constant, it does slow down when travelling through different transparent mediums.

Question 2

what is Refraction

Answer 2

the change in direction of a light ray due to a change in speed when light travels from one medium into the other of different optical density.

Question 3

what is optical density

Answer 3

When light travels from one optical medium to another it either slows down or speeds up depending on whether the medium is dense or not. Thedenser the medium theslower the speed of light.

Question 4

why does light slow down when it goes into a more dense medium

Answer 4

When light travels from space (which is a vacuum) into the air, it will slow down. The easiest way to understand it is that the protons of light are absorbed and re-emitted every time it comes across a particle, so that absorption and emission takes a bit of time, and hence it slows down.

Question 5

how does refraction work when light travels from one medium to another

Answer 5

The bigger the difference in the speed of light between two mediums, the more it will refract or bend as it goes from one medium to another.

Question 6

what is the refractive index

Answer 6

The refractive indexof a material is the ratio of the speed of light in vacuum (c) to the speed of light in a material (v).

Question 7

what is the formula for refractive index

Answer 7

n = c/v

nis the refractive index

cis the speed of light in a vacuum

vis the speed of light in the other medium

Question 8

what is the angle of incidence

Answer 8

Angle of incidence:The angle between the normal to a surface and the incident light ray.

Question 9

what is the angle of refraction

Answer 9

Angle of refraction:The angle between the normal to a surface and the refracted lightray.