some ugly definitions Flashcards
1
Q
principle axis
A
is the line joining the 2 centres of curvature
2
Q
optical center
A
`the point on the principal axis through which a ray of light may pass undeviated
3
Q
principal focus
A
all rays that are parallel to the principal axis are refracted such that they pass or appear to pass through a point on the principal axis called the principal focus
4
Q
focal length
A
the distance between the optical centre and the principal focus
5
Q
how many foci does a convergent beam have
A
two; object and image focus