1
Q
What can happen to a parallel beam of light?
A
Can be converged to a focus in the focal plane.
2
Q
If a light beam is parallel to the principal axis where will the focal point be?
A
On the principal axis.
3
Q
Where will a diverging light beam from a near object focus?
A
Beyond the focal plane.
4
Q
How does a camera work?
A
- Box with a lens at one end and a film at the other
- Light from an object passes through the lens and is focused on the film
- The size of the image is smaller than the object
5
Q
How does a projector work?
A
- In a projector, the film is placed closer to the lens than the object is to the camera
- Light from a bulb passes through the film and the lens and is focused on the screen
- The size of the image is larger than the object
6
Q
Where will the path of two rays follow from the top of an object?
A
- The ray parallel to the principal axis (principal ray) will refract through the focal point
- The ray that passes through the centre of the lens (central ray) does not deviate
- Where the rays meet is the top of the image
7
Q
What is a virtual image?
A
Formed by a magnifying glass, cannot be projected onto a screen because no light passes through it and is the right way up.
