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Focal Length of LensesDaniel Stokes@027230303/31/15Physics Lab 002-05Richard JohnsonYakntoro Udoumoh
ObjectiveTo measure the focal length of convex (positive or convergent) lenses and concave (negative or divergent) lenses. TheoryA lens is a transparent object with two refracting surfaces whose central axes coincide. Diverging lenses are concave lenses where the rays diverge. Converging lenses are convex lensesthat converge to the central axis. For the lenses the real image forms on the opposite side of thelens while the virtual image is on the same side as the object. Diverging lenses do not form real images. If we have an object distance of d, and an image distance ofI,then the focal length fis related by the formula below:1f=1d+1iApparatusOptical bench, lens holders, screen, lamp, convex lenses, and concave lenses.ProcedureConvex Lens1.Place the lamp and screen on the optical bench about 40 cm apart.