Plano-Convex Lens Lab Report

The goal of the first part of the experiment was to examine the focal lengths of various thick lenses, spherical aberration, and 1D magnification. First, we observe that the focal length does not seem to change when we move the lens closer and farther away from the box. Then, we find that the light rays converge after passing through the bi-convex and plano-convex lens and diverge after passing through the bi-concave lens. Therefore, the focal length of the bi-concave lens is negative. We also observe that the focal length of the plano-convex lens is greater than that of the bi-convex lens, which is due to the fact that one side of the plano-convex lens is flat while the other side is convex. When trying to observe spherical aberration, we …show more content…
We find a final separation distance of is (0.0045 ± 0.0005) m. From Equations 8 and 11, we find that the magnification factor is 0.50±0.06. The magnification factors of the two set-ups are inverses since the first set-up doubles the separation and the second halves it. This is expected since we reversed the order of the lenses. The goal of the second part of the lab was to find the focal lengths and dioptric powers of various lenses. After measuring the focal lengths, we calculated the dioptric powers of the lenses using the fact that the dioptric power, P, is the inverse of the focal length. The uncertainties for the calculations in Table 2 were found using the following equation:

δP=P_best δf/f

where P_best is the calculated dioptric power, f is the focal length, δf is the uncertainty of the focal length. The fourth row of Table 2 contains the data relevant to the combination of the two thin lenses (3.5 cm diameter and 4.0 cm diameter). The theoretical dioptric power of the two thin lenses together is given by the following