Refraction of light

Question 1

Refraction

Answer 1

1. Light bends when it passes from one medium to another of different density
2. As it passes into a denser medium it slows down
3. This is because the wavelength decreases while frequency stays the same

Question 2

Laws of refraction

Answer 2

1. Sin i/Sin r is constant for two given media (Snell’s Law) ( i = angle of incidence, r = angle of refraction)
2. The incident ray, the refracted ray, and the normal are all in the same planes

include:
n = sin i/sin r + notation

Question 3

Refractive index formulas

Answer 3

Sin i/Sin r

Real depth/Apparent depth

c₁/c₂ (speed of light in medium 1 (normally air) divided by speed of light in medium 2)

1/Sin C (critical angle)

Question 4

Refractive index symbol

Answer 4

n

Question 5

Refraction diagram

Answer 5

in hardback

Question 6

at night, when the lamp is switched on, a disc of light is seen at the surface of the swimming pool. Why does the area surrounding disc of light appear dark in the water?

Answer 6

no light emerges from pool due to total internal reflection

Question 7

why is each fibre (optical fibre) coated with glass of lower refractive index?

Answer 7

so that total internal reflection occurs and no light escapes

Question 8

refraction of light

Answer 8

the bending of light on passing from one medium to another

Question 9

when finding refractive index

Answer 9

refractive index is the ratio of the speed of light in a vacuum to the speed of light in a medium, so when finding the refractive index of a medium, imagine it if it was going into the medium even if the diagram shows the light ray leaving the medium

ie. if ray of light is leaving medium, angle of incidence is angle of refraction and vice versa when you use the formula sin i/sin r

Question 10

angle of incidence diagram

Answer 10

angle of incidence is the inner angle, opposite angle from it is the angle of refraction (look at diagram)