derived from the graphical method is closer to the actual given value than the

Derived from the graphical method is closer to the

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3 Part C: Convergent + Divergent LensesIn the final setup of our experiment, a divergent lens of focal length -.150m or -150mm iscombined with the convergent lens from Part 1. The same procedure and comparisonmethods from the previous two parts of the experiment are repeated. 3.1 Experimental Data Table 3.1 My caption Setup d o (m) 1 d o (m) d i (m) 1 d i (m) Focal length Avg. Focal Length ± std dev. 0.134 ± 0.003 1 0.251 4 ± 0.02 0.275 3.64 ± 0.01 0.131 ± 0.0004 2 0.281 3.56 ± 0.01 0.246 4.07 ± 0.02 0.131 ± 0.0004 3 0.325 3.08 ± 0.01 0.222 4.50 ± 0.02 0.132 ± 0.0004 4 0.204 4.90 ± 0.02 0.42 2.38 ± 0.01 0.137 ± 0.0005 5 0.191 5.2 ± 0.03 0.474 2.11 ± 0.01 0.136 ± 0.0005 ± 0.001 0.001 Table 3.2 My caption Effective focal length, using lens holder values 50mm % error Focal length from graph 0.134 ± 0.003 18 Focal length from average 0.123 ± 0.003 11 10
3.2 Graphs associated with Part C Figure 5 Lens 1 - 75mm combined with Divergent Lens - (-)150mm 3.3 Data analysis Effective focal length = 1 1 f 1 - 1 f 2 = 1 1 0 . 075 + 1 0 . 150 = 0 . 150 m (11) 3.4 Conclusion to part C Interestingly, the calculated values were reasonably close to each other in value, but when comparing to the actual value of the effective focal length, our resulting percent error was quite large and our calculated error could not account for it. Possible factors of error can be attributed to the space between the two lenses as well as human error when determining positions when the resulting image on the screen was sharpest. 11

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