Refraction

Question 1

Name a rule of refraction

Answer 1

A beam of light will always bend towards the normal when passing from a less dense to a more dense medium

Question 2

What is the bending of light called

Answer 2

Refraction

Question 3

What happens with different wavelengths of light?

Answer 3

The amount of refraction increases as the wavelength of light decreases

Question 4

What does a material have and what is it?

Answer 4

A refractive index

A value based on the density of materials

Question 5

What happens when a beam of light hits a dense material

Answer 5

As it enters, it bends towards the normal, when it leaves, it bends away from the normal

Question 6

What is the normal

Answer 6

An imaginary line that is perpendicular to the edge of the surface of the denser material

Question 7

What does monochromatic mean?

Answer 7

A single colour

Question 8

What happens when a monochromatic beam of light passes from air to water?

Answer 8

It is refracted at an angle determined by the refractive index of water

Question 9

What does refract mean?

Answer 9

Make a beam of light change direction when it entere something

Question 10

What is angle of incidence labelled as?

Answer 10

Øvi

Question 11

What is angle of refraction labelled as?

Answer 11

Øvr

Question 12

What is the angle of the exit beam labelled as?

Answer 12

Øvi because angle of incidence is always equal to the angle of the exit beam

Question 13

What is the equation for the refractive index?

Answer 13

n = sinØvi/sinøvr

Question 14

The angle of incidence is 23.1 and the angle of refraction is 14.9. Work out the refractive index and material

Answer 14

n = sinØvi/sinøvr

n = sin(23.1)/sin(14.9)
n = 1.525

Question 15

What is the refractive index of glass?

Answer 15

1.52

Question 16

The material is glass. Work out the angle of refraction if the beam enters the glass block at an angle of 35⁰

Answer 16

n = sinØvi/sinøvr
1.52 = n = sin(35)/sinøvr

Rearrange to get:
Øvr = sin^-1(sin(35)/1.52)
Øvr = 22.2⁰

Question 17

What will happen if 0vi becomes so large that it becomes perpendicular to the normal?

Answer 17

No refraction will take place

Question 18

Think on example of where we have a ray travelling from a more dense medium to a less dense medium. What happens if keep increasing the Øvi?

Answer 18

The Ø gets bigger and bigger until it is equal to 90°

Question 19

What happens when Øvi and Øvr are equal to 90°

Answer 19

There will be no further refraction and the light ray will reflect internally

Question 20

How do we calculate the critical angle

Answer 20

SinØvc = nv2/nv1

Question 21

What is critical angle in equation from?

Answer 21

SinØvc

Question 22

Use the equation for critical angle, nv1 = 1.52 nv2 = 1.00

Answer 22

Øvc = sin^-1(1/1.52)
Øvc = 41.1°

Question 23

What is the angle called where refraction is internalised?

Answer 23

Critical angle

Question 24

What is refractive index in equation terms?

Answer 24

n

Question 25

What do n^1 and n^2 represent?

Answer 25

n^1 = more dense medium
n^2 = less dense medium