Lens Flashcards
When is the image real and the same size as the object?
Where is it and example?
At a distance 2F
Inverted at 2F and uses in a photocopier or printer
When is the image real, magnified and been inverted?
Where does it lie and example?
At a distance between 2F and F
Lies beyond 2F and used in a microscope or projector
1 - real, infinitely large, inverted image. Formed where? What distance?
2 - virtual, infinitely large, upright image. Formed where? Example?
1 - formed at infinity from a distance F.
2 - formed at infinity and used to produce parallel beams of light, as in a spotlight with a lamp at F
Virtual, upright image that is magnified. Example?
At a distance below F and is magnified at a distance beyond F.
Used in microscopes, magnifying glass and to correct long sightedness
At a distance from the lens to real objects images and focuses are?
Positive values
The distance from the lens to Virtual objects images and focuses are?
Negative values
f is positive for what?
a converging lens which has a real focus
f is negative for?
A diverging lens which has a virtual focus
What is the distance from the optical centre of the lens to the object called?
The object distance, u
The distance from the optical centre to the lens to the image is called?
Image distance, v
What is a convex lens?
It converges, brings together rays of light
What is a concave lens?
It diverges, spreads out rays of light
What is the principal axis
It is the line on the lens joining the centre of the curvature of its surfaces
What is the optical centre of the lens?
The point midway between the lens surfaces on the principal axis where the rays are not diverted
What is the focal length?
The distance between its optical centre and principal focus
