Refraction

Question 1

What is refraction and what is not refraction ?

Answer 1

When a wave crosses a boundary between two materials, it changes speed.
If wave is travelling through the normal it’ll change speed but not be refracted.
If waves hits boundary at an angle, it’ll change direction = refraction

Question 2

If wave ———— towards normal, it’ll ———— down
If wave ———– away from normal, it’ll ——– up

Answer 2

bends, slow
bends , speed

Question 3

How much its refracted by depends on ..

Answer 3

how much the wave speeds up or slows down which depends on density of the two materials ( denser = slow waves travels through it )

Question 4

when light travels from less dense ( air ) into more dense material ( glass ), Will the wave bend towards or away from normal ?

Answer 4

towards

Question 5

Define the optical density of a material

Answer 5

measure of how quickly light can travel through it - higher optical density, slower light waves travel through it

Question 6

Wavelength of a ———— ———— ,when is it ————-, but the ————— ————- the ———–

Answer 6

wave changed, refracted , freq, stays, same

Question 7

what happens to wavelength as it moves into more dense medium

Answer 7

wavelength will decrease

Question 8

ray diagram

Answer 8

https://www.bbc.co.uk/bitesize/guides/znksd6f/revision/6

Question 9

Angle of ————- is ————– than angle of ————- is second material is more optically dense

Answer 9

refraction , smaller, incidence

Question 10

Explaining refraction using wave front diagram

Answer 10

Wave front shows all the points of a wave that are in same position as each other after given number of wavelengths

When a wave crosses a boundary at an angle, only part of the wave front crosses the wave boundary at first. If its travelling into denser material, that part will travel slower than the rest of the wave front.

So by time the whole wave front has crossed the boundary, the faster part of the wave front will have travelled further than the slower part of the wavefront.

The difference in distance travelled by wave front causes the waves to bend - refract