P14 light, sparse Flashcards
1
Q
what is a virtual image?
A
an image formed from where light rays appear to come from, after having been reflected or refracted
2
Q
two types of reflection and compare them
A
specular
reflection from a smooth surface in one direction
diffuse reflection
reflection from a rough surface in many directions
3
Q
what direction does light refract as it enters a denser medium
A
towards the normal
4
Q
how do colour filters work
A
absorb some wavelengths (become invisible)
and reflect others (visible)
5
Q
primary colours of light
A
red
green
blue
6
Q
what is the principal focus of a lens
A
where rays seem to be concentrated
convex: where they meet
concave: where they appear to start from
