refraction of light Flashcards Preview

10 science-- optics > refraction of light > Flashcards

Flashcards in refraction of light Deck (31)
Loading flashcards...
1

refraction

the bending of light as it travels at an angle from one medium to a different medium

2

how does light travel in the same medium?

in a straight line and at a constant speed

3

what happens when light travels from one medium to another?

the light rays refract ("bend")

4

fermat's principle

when light travels from one point to another, it follows the path that will take the least time
in a single medium, the path that takes the least time is a straight line

5

refracted ray

ray that is bent upon entering a second medium

6

angle of refraction

the angle between the normal and a refracted ray

7

angle of incidence ___ angle of reflection

=

8

when does the light ray bend towards the normal?

a light ray travels from a medium in which its speed is faster (less dense medium) to a medium in which its speed is slower (denser medium)

9

when does the light ray bend away from the normal?

a light ray travels from a medium in which its speed is slower (denser medium) to a medium in which its speed is faster (less dense medium)

10

how much a light ray refracts is determined by _____________

the extent of the change in the speed of light as it travels from one medium to another

11

when light passes from one medium to the next and the change in the speed of light becomes greater (faster), the angle of refraction becomes ________

greater

12

index of refraction (n)

ratio of the speed of light in a vacuum divided by the speed of light in a given medium

13

what does the n stand for in n = c/v?

index of refraction

14

what does the c stand for in n = c/v?

speed of light in a vacuum

15

the speed of light in a vacuum

3 x 10 to the power of 8 m/s

16

what does the v stand for in n = c/v?

speed of light in a particular medium

17

why is the index of refraction always greater than 1?

the speed of light is always higher in a vacuum than in a medium

18

dispersion

the process of separating colours by refraction

19

each colour of light travels at ______________ in any medium

a slightly different speed

20

when do all the wavelengths of light and all the other forms of electromagnetic waves travel at the same speed (speed of light)?

only in a vacuum

21

when does partial reflection and refraction occur?

as light reaches a boundary between two media

22

in partial reflection and refraction, some light is reflected and some is refracted, but ___________

not equally

23

as the angle of incidence increases, more light will be _______ and less _________

reflected / refracted

24

critical angle

angle of incidence that produces an angle of refraction at 90 degrees and no light passes into the second medium

25

what does the critical angle depend on?

the optical densities of the 2 media

26

when does total internal reflection occur?

when the angle of incidence increases past the critical angle

27

how can total internal reflection occur?

light travels from a more dense medium (speed is lower) to a less dense medium (speed is higher)
the refracted ray angle increases more than the incident angle moving away from the normal towards the boundary of the two media

28

total internal reflection
eventually the refracted ray hits 90 degrees, the incident angle at which this occurs is called the __________

critical angle

29

total internal reflection
as the incident ray angle increases beyond the critical angle, the light no longer refracts because ___________

the refracted ray would no longer be in the second medium; all the light is reflected back into the first medium

30

for angles of incidence greater than the critical angle, _________ occurs

total internal reflection