PURPOSE: To determine the focal point of a concave lens.
DESCRIPTION: Parallel rays incident on a diverging plano-concave spherical lens appear to emanate from the focal point of the lens. Two diverging lenses can be placed together to increase the divergence and decrease the focal length. A slit baffle with concave and convex lenses are used to create the set of parallel rays, which can be varied in number and in spacing.
REFERENCES: (PIRA 6A60.10)
EQUIPMENT: Optical board with diverging lens, convex and concave lens to produce parallel rays.
SETUP TIME: None.
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