4.6.2.6 Visible Light (physics only)

Question 1

What does each colour within the visible light spectrum have?

Answer 1

each colour within the visible light spectrum has its own band of wavelength and frequency

Question 2

Specular reflection:

Answer 2

reflection from a smooth surface in a single direction

Question 3

Diffuse reflection:

Answer 3

reflection from a rough surface - causes scattering

Question 4

How do colour filters work?

Answer 4

colour filters work by absorbing certain wavelengths (and colour) an transmitting other wavelengths (and colour)

Question 5

How is the colour of an opaque object determined?

Answer 5

• colour of an opaque object is determined by which wavelengths of light are more strongly reflected
• wavelengths that are not reflected are absorbed

Question 6

When does an object appear white?

Answer 6

if all the wavelengths of an object are reflected equally the object appears white

Question 7

When does an object appear black?

Answer 7

if all wavelengths are absorbed by the object then it appears black

Question 8

What are objects that transmit light?

Answer 8

Transparent or translucent

Question 9

Primary colours of light:

Answer 9

• red
• green
• blue

Question 10

Red + green

Answer 10

Yellow

Question 11

Red + blue

Answer 11

Magenta

Question 12

Blue + green

Answer 12

Cyan

Question 13

Red + green + blue

Answer 13

White light