PURPOSE: To show the systematics of real image formation by a converging lens.
DESCRIPTION: A key lit from behind by a bright point source of light is used as the object, and various convex lenses are used to cast images of the key onto a movable screen. The effect of variation in focal length and object distance can be readily seen. Combinations of two convex lenses or a concave and a convex lens used together can also be demonstrated.
REFERENCES: (PIRA unknown.)
EQUIPMENT: Bright point source with condenser lens, object key, 10cm, 20cm, and 50cm focal length convex lenses, 20cm focal length concave lens, and screen, on rolling optical table with extension arm.
SETUP TIME: 5 min.
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