Light Flashcards
(20 cards)
Name the 2 types of light sources
1.Luminous (make their own light)
2.Illuminate (needs light shining on them)
Which energy pathway transfers light from source to surrounding areas?
Radiation pathway
Does brightness increase or decrease with distance from the light source?
Decrease
What does transparent medium mean?
Light travels through clearly, like through clear glass.
What does translucent medium mean?
Light travels through but not as clearly, like through a frosted window.
What does opage medium mean?
Light does not pass through it, causing shadows.
What is the equation for the law of reflection?
The angle of incidence = the angle of reflection
True or false: All surfaces reflect light and obey the law of reflection?
TRUE
What is a ray?
An imaginary line drawn to represent the path light is travelling
What 3 colours do eyes detect?
Red, green and blue
REFLECTION
What are the laws of relection?
The angle of includicene
REFLECTION
What is specular reflection?
- Light reflects off a smooth, shiny surface
- all rays bounce in the same direction
- Create a clear image.
Mirror, still water, polished metal.
REFLECTION
What is diffuse reflection?
- Light reflects off a rough surface
- Rays scatter in many directions
- No clear image is seen.
Paper, walls, wood, skin.
REFLECTION
Do most surfaces reflect light specularly or diffusely?
Most surfaces reflect light diffusely, meaning they scatter the light.
REFRACTION
What is refraction?
Refraction is when light changes direction as it passes from one material to another.
REFRACTION
What happens to light when it enters a more dense material (like air to glass)?
It slows down and bends towards the normal.
REFRACTION
What happens to light when it enters a less dense material (like glass to air)?
It speeds up and bends away from the normal.
REFRACTION
What is the “normal line”?
A dashed line at a right angle (90°) to the surface where the light hits — used to measure angles of incidence and refraction.
REFRACTION
What is the “angle of incidence”?
The angle between the incoming light ray and the normal line.
REFRACTION
What happens when the angle of incidence increases?
There is more refraction — the light bends more.
