Light Flashcards
How is a spectrum produced from white light?
A prism splits white light into the component colours
What colour will an orange t shirt look under a red filter?
Red because orange is made of red and yellow and yellow is made of red and green. The red light goes through the filter but the green is absorbed and does not go through.
What colour will a blue t shirt look under a yellow filter?
Black as there is no blue light reflected by the blue t shirt
Why does a purple t shirt look blue under a blue filter?
Because a purple t shirt reflects both blue and red light so the filter lets blue light through but absorbs the red light.
Why does a blue t shirt look blue?
The dye used to colour the t shirt absorbs red and green light but reflects blue light so it looks blue.
How does a mirror reflect light?
The mirror has a silver surface which reflects all light.
In reflection what is a normal?
A normal is a line drawn at 90 degrees to the surface where the light hits.
What is specular reflection?
Specular reflection is where the light is reflected from a flat surface in a parallel beam (all going in the same direction)
What is diffuse reflection?
Diffuse reflection happens when light hits a rough surface so the light reflects off in lots of different directions.
What is the law of reflection?
The angle of incidence and the angle of reflection are equal.
What are the primary colours of light
Red, green, blue
What are the secondary colours of light?
Cyan, magenta, yellow
What two colours of light are added together to make yellow light?
Red and green
What two colours of light are added together to make cyan?
Green and blue
What two colours of light are added together to make magenta?
Red and blue
