Topic 5 Flashcards
What is diffuse reflection
Happens when light if reflected by a rough surface this is because the light is scattered
What is speculate reflection
Specular reflection happens when light is reflected by a smooth surface in a single direction.
What is total internal reflection
If the angle of incidence exceeds the critical angle then all the light will be reflected
What happens when the critical angle of incidence is exceeded
All the light is reflected
What are the conditions for total internal reflection
Critical angle is exceeded
The medium is entering a substance with a lower optical density
What is refraction
When light travels into a less optically dense medium
if all wavelengths are reflected equally what colour will an opaque object look
White
Why does a blue book look blue
Because every colour from the visible light spectrum is absorbed except from blue which is reflected
If a blue book was looked at through a red filter what colour would it look
Black. This is because the red filter will only allow red light to pass through
It will absorb all other colours of light
How does a lens form am image
By refracting light
What is the strength of a lens identified by
It’s power. Thus is worked out from the focal length and this varies with shape
What happens when the focal length is larger
Lower power
Describe convex lenses and there shape and how they show the power of the lens
the thicker the middle of the lens compared with the edges, the larger the power.
Describe concave lenses and there shape and how they show the power of the lens
the thinner the middle of the lens compared with the edges, the larger the power.
What is another name for convex lenses
Converging lens
