PASCO OS-8515C Basic Optics System - Manual (Page 41)

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M o d e l N o . O S - 8 5 1 5 C E x p e r i m e n t 1 4 : V i r t u a l I m a g e s
41
Experiment 14: Virtual Images
Purpose
In this experiment, you will study virtual images formed by a diverging lens and a
convex mirror.
Theory
A virtual image cannot be viewed on a screen. It forms where the backwards exten-
sions of diverging rays cross. You can see a virtual image by looking at it through a
lens or mirror. Like all images, a virtual image formed by a lens or mirror can serve as
the object of another lens or mirror.
Part I: Virtual Image Formed by a Diverging Lens
In this part, you will set up a diverging lens to form a virtual image. You will then use
another lens to form a real image of the virtual image. In this way you can identify the
location of the virtual image.
Procedure
1. Place the -150 mm lens on the bench at the 30 cm mark.
2. Place the light source at the 10 cm mark with the crossed-arrow object toward the
lens.
3. Record the object distance d
o1
(the distance between the light source and the
lens) in Table 14.1.
Figure 14.1
Required Equipment from Basic Optics System
Light Source
Bench
-150 mm lens
+200 mm lens
Viewing screen
Concave/convex Mirror
Half-screen
Other Equipment
Tape
Light
source
-150 mm
Lens
10 cm 30 cm
Look through lens