Questions on imaging using Lenses

1. Why is it possible to find the location and size of an image by tracing only two rays from the tip of the arrow head representing the object?
2. What is the law of reciprocity?  Give an example using a ray diagram.
3. Use ray tracing to locate the image of a real object located a distance of three times the focal length in front of a converging lens.
4. Repeat the above question for the case that the object distance is smaller than a focal length.
5. Can the magnification of a real image of a real object be smaller than one?  Larger than one?
6. Are images of real objects through a converging lens always inverted?  How could you make the real image be erect?
7. When will the image of a real object in a converging lens be a virtual image?  How do you see the virtual image?  Draw a sketch showing where to put your eye.
8. Are the images formed on your retina real or imaginary?  Are they erect or inverted?
9. Answer the previous question for the images formed on film in a camera.
10. Draw a ray diagram for a real object located in front of a diverging lens. Explain your results.
11. Draw a ray diagram to show how a converging lens can correct for a far-sighted eye.
12. Do diverging lenses always produce virtual images? Do they always have a magnification less than one?
13. Show in a ray diagram how a diverging lens corrects for a near-sighted eye.
14. Explain how a manual camera is made to "focus". How is this done in an automatic camera? How are these cameras different from a point-and-shoot type?

Last Modified: Tuesday, 23-Sep-2003 malekis@union.edu