Thin Lenses Homework
Read pg. 661-664 and answer the following
1. Where are lenses used?
2. A thin lens is usually __________________________________ and has two faces that are
portions of a _____________________________.
3. What shape can the faces of lenses be?
4. Where is the axis of a lens?
5. Describe what happens in a lens as light rays go through the lens:
6. Parallel rays will come to ___________________________ on the other side of the lens
7. The distance of the focal point to the center of the lens is called the
________________________________________.
8. Even if the lens surfaces are different, if you turn the lens around the focal
length will _________________________________________.
9. A converging lens is _________________________________ in the center and will make
parallel lines that ____________________________
10. A _________________________________lens is thicker on the edges and makes the
parallel light rays __________________________.
11. P=1/?
12. The unit for lens power is the ___________________________.
13. For a converging lens, The image position of an object can be measured by
knowing the focal length.
14. Look at 23-37 on pg 663 to see the best way to draw a ray diagram for a
converging lens and draw or describe the ray diagram for a converging lens:
15. Now draw or describe a diverging lens:
16. Thin lens equation for converging lenses
17. And for diverging lenses:
18. Explain the sign conventions for the lens equations:
19. Explain the steps to solving problems for thin lenses
20. Solve example 23-12 here:
21. Explain how to solve converging lens and diverging lens problems using
example 23-13 and 23-14
Time to practice: do problems on pg 675 numbers 41, 47 and 55