convex lens Flashcards
(8 cards)
1
Q
Parallax
A
When two objects appear to move relative to each other when you shift your viewpoint — used to identify when image and object are in the same plane.
2
Q
Focal length (f)
A
Distance from the lens to the image point when parallel light enters.
3
Q
Power (F):
A
F=1/f (in metres).
4
Q
Magnification (m):
A
𝑚=𝑙′/𝑙 = 𝐿′/𝐿
use distances and vergences to calc m
5
Q
Plane mirror method
A
Object → convex lens → mirror → image reflected back. Measure f.
6
Q
No-parallax pin method:
A
Pin → lens → mirror → find no parallax → measure f.
7
Q
Focal length of a convex lens
A
positive
8
Q
Parallax disappears when
A
object and image are in the same plane
