User:Boleszek/Notebook/Physics 307l, Junior Lab, Boleszek/2008/10/13

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Equipment and Setup Pasco OS-9282 Hg light source Pasco AP-9368 h/e Apparatus Tektronix TDS 1002 digital oscilloscope Wavetek true RMS DMM - We connect the output of the h/e apparatus to the DMM and Oscilloscope. - Using wall socket (120V) as power source for lamp - 2 9V batteries bower the h/e apparatus Not much setup is required Procedure and Data Acquisition • Part A. Yellow band is centered on the opening and yellow filter is put in place. We cover this with the variable transmission filter using the 100% section. The DVM represents the signal from the h/e apparatus. After charging the signal is constant (DC). In order to avoid human error of alignment we take all measurements at different intensities (positions of the filter) for a single color. 1ST TRY Data 20% Color max(V) time1 time2 time3 time4 time 5 Yellow 7.06 24.31 32.16 30.25 26.47 33.54 Orange 3 Green Purple Data 40% Color max(V) time1 time2 time3 time4 time 5 Yellow 7.05 26.63 11.44 14.50 12.90 14.03 Orange 3 Green Purple Data 60% Color max(V) time1 time2 time3 time4 time 5 Yellow 7.06 15.13 15.50 16.19 16.22 17.06 Orange 3 Green Purple We decide that the choice of voltage we had to reach (7.03V) was a bad one since it is on the far tail of the charging scale and the voltmeter tends to jump back and forth between numbers as it slowly reaches the saturated stopping voltage. We decide to use 7V as the cutoff. 2ND TRY Redo measurements Data 20% Color max(V) time1 time2 time3 time4 time 5 Yellow .706 33.94 27.00 31.15 28.59 31.06 Orange 3 Green Purple Data 40% Color max(V) time1 time2 time3 time4 time 5 Yellow .706 13.81 18.47 23.87 21.91 23.66 Orange 3 Green Purple Data 60% Color max(V) time1 time2 time3 time4 time 5 Yellow .706 22.34 19.81 22.03 23.72 23.03 Violet The closeness of these values to the previous ones makes us skeptical, so we retake the 60% data 3RD TRY Data 60% Color max(V) time1 time2 time3 time4 time 5 Yellow .706 6.66 5.25 6.00 5.06 5.75 Violet 1.46 7.06 7.66 7.31 6.97 7.19 Data 80% Color max(V) time1 time2 time3 time4 time 5 Yellow .706 4.37 5.19 4.13 4.25 4.03 Violet 1.46 4.41 5.44 5.22 5.25 5.46 Data 100% Color max(V) time1 time2 time3 time4 time 5 Yellow .706 3.69 3.50 4.28 4.50 4.19 Violet 1.46 4.88 4.56 4.44 4.62 4.65 Data 40% redo Color max(V) time1 time2 time3 time4 time 5 Yellow .706 8.00 8.42 6.72 8.75 7.59 Violet 1.46 8.72 9.68 9.68 9.75 8.84 Data 20% redo Color max(V) time1 time2 time3 time4 time 5 Yellow .706 8.25 8.75 9.20 9.06 9.28 Violet 1.46 16.50 19.06 19.30 17.12 16.80 Darrel has noticed that the time measurements tend to be longer when his hand is left touching the h/e apparatus after pressing the discharge button. We decide to redo the measurements of 40% and 20% for yellow and are finally satisfied with the apparent linearity of our measurements. We proceed to make measurements using a violet strip. We choose 1.42V as our voltage to reach. • Part B Violet Blue1 Blue2 Yellow Green Max(V) 1.49 1.71 2.044 .716 w/filter, .993/without .847 with, .972 without