AstroPhysics Flashcards
1
Q
what are the 2 types of lense
A
convex and concave
2
Q
what do convex lenses do
A
focus incident light
3
Q
what do concave lenses do
A
spread out incident light
4
Q
what is the principle axis
A
the line passing through the centre of the lens at 90˚to its surface
5
Q
what is the focal length
A
the distance between the centre of a lens and the principal focus
