Lenses Practice Problems
AP Physics
Name:
Period:
You should have learned how to do ray diagrams for lenses in class. In problems 1 – 5, you will use those skills
to produce rays diagrams for the following situations. For each problem:
a. Draw all three of the convenient light rays to locate the image produced by the lens and draw in the image
b. Label the characteristics of your image: size, distance, type of image, orientation of image.
1.
2.
3.
4.
5.
6.
μ. If you feel inspired, you can go back and check some or all of your drawings by measuring the object
distance & height and focal length and applying the thin lens and magnification equations to find the
characteristics of the image then compare them to the image you found from your drawing.
7.
a)
b)
c)
d)
e)
Which of the following statements are accurate for diverging lenses?
A diverging lens must have at least one concave surface
A diverging lens always produces a virtual image
A diverging lens is thinner at the center than at the periphery
A diverging lens always produces an image that is smaller than the object
A diverging lens always produces a real image
8. What is the name for the lens aberration caused by dispersion in the lens?
9. Does a converging lens ever form a virtual image of a real object? If so, when?
10. An object is placed 50.0 cm in front of a converging lens of foacal length 10.0 cm. What are the distance
and height to the image produced?
11. An object placed 30 cm in front of a converging lens forms an image 15 cm behind the lens. What is the
focal length of the lens?
12. A converging lens with a focal length of 20 cm is used to produce an image on a screen that is 2.0 m from
the lens. What is the object distance?
13. An object 4.0 cm tall is in front of a converging lens of focal length 22 cm. Where is image formed and
what are its characteristics for each of the following object distances?
a) 15 cm
b) 36 cm
14. An object placed in front of a biconcave lens whose focal length is 18 cm. Where is the image formed and
what are its characteristics for each of the following object positions?
a) 10 cm away from the mirror
b) 35 cm away from the mirror
15. A biconvex lens has a focal length of 0.12 m. Where on the lens axis should an object be placed in order to
get each of the following types of image?
a) A real, enlarged image with a magnification of 2.0
b) A virtual, enlarged image with a magnification of 2.0$
16. a) Design a single lens projector that will form a sharp image on a screen 4.0 m away from the projector
while the slide sits 6 cm before the lens. What part or parts do you need to produced this projector?
b) If the object is a slide that 1.0 cm tall, how tall will the image on the screen be?
c) How should the slide be placed in the projector. Explain.
17. A 5.0 cm tall object is 10 cm from a concavo-concave lens. The resulting image is 1/5 as a large as the
original object. What is the focal length of the lens?