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course Phy 202
12/10 12
PhET Explorations: Geometric OpticsHow does a lens form an image? See how light rays are refracted by a lens. Watch how the image changes when you adjust the focal length of
the lens, move the object, move the lens, or move the screen.
Figure 25.26 Geometric Optics ( http://cnx.org/content/m42466/1.4/geometric-optics_en.jar )
As I increase the focal length, the inverted image appears closer to the lens. When I move the lens closer to the principal object, the inverted image moves farther away from the lens. As the curvature radius of the lens decreases, the inverted image becomes smaller and moves closer to the lens. The opposite happens when increasing the curvature radius. Increasing the refractive index of the lens causes the inverted image to become smaller and move closer to the lens. Increasing the diameter of the lens causes the inverter image to become brighter and more visible.
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Very good.
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