refraction of light

Question 1

why are light waves refracted when they travel across a boundary between air and a transparent medium

Answer 1

because the speed of light changes at this kind of boundary as the transparent medium is more optically dense

Question 2

what happens when light travels from air to glass

Answer 2

it is directed towards the normal, the angle of refraction is less than the angle of incidence

Question 3

what happens when light travels from glass to air

Answer 3

it is directed away from the normal, the angle of refraction is more than the angle of incidence

Question 4

what is refraction

Answer 4

change in direction of waves when they travel across from one medium to another.

Question 5

why might you see a faint mirror image of yourself when you look at a window

Answer 5

because when waves cross a boundary between two materials, partial reflection can also happen as well as refraction

Question 6

when a narrow beam of white light passes through a triangular glass prism, what happens and why?

Answer 6

the ray comes out of the prism in a different direction to the incident ray and is split into colours of the spectrum. this is because the speed of light in glass depends on wavelength, and therefore on the colour of the light. for example, blue light travels slower in glass than red light, so it is refracted more.