Unformatted text preview: otted the current as a function of the voltage in Figure 1 to get an experimental value for 1/R from the slope of a linear regression. As can be seen on the graph, our slope was m = 0.001 (m = 0.00007 and b = 0.00001 from Excel) and taking the inverse of that gave us an experimental resistance of 1000 ohms. Our resistance data is summarized below. Table 6: Shows the experimental resistance and its actual measured resistance. Rexp (ohms) 1000 0.00007 Next, I analyzed our diode circuit in order to find an experimental ratio between e/kB which we could compare to the theoretical ratio. First, I calculated the theoretical ratio, which is summarized in Table 7. I calculated current data by Rmeasured (ohms) 993 0.05 R 7 R % 1.41 dividing the voltage data collected for r by our measured resistance of r. I then linearized the current data and plotted it against the voltage data in Figure 2, which allowed us to use a linear regression to find the experimental ratio. The slope of that regression can be seen in Figure 2 to be m = 20.602 (m = 0.04074 and b = 0.02745 from Excel), which when multiplied by n*T yields a ratio of 12072.8. All of the data is summarized in the table below. Table 7: Summarizes the theoretical and experimental ratios between e and kB. e (C) kB (J/K) e/kB_th r (ohms) n 1.6022E-19 1.3806E-23 11604.9 99.2 2 T (K) e/kB_exp ratio 293 12072.8 467.9 ratio % 3.95 In the AC portion of the lab, we were allowed to choose either the RC or the RL data to analyze and find the experimental time constant for the circuit. I chose to analyze the RC circuit. Again, we had to linearize the voltage data in order to take an approximate a linear regression. That data is plotted below in Figure 6 and resulted in a regression slope of m = -923.81 (m = 11.2747 and b = 0.04183 from Excel). Taking the inverse of this slope gave us an experimental time constant of 0.00108. Voltage (Linearized) vs Time 2 1.5 ln(Vb - V) (v) 1 0.5 0 -0.5 -1 -1.5 -2 Time (s) 0 0.002 0.004 0.006 0.008 trans time Linear (trans time) y = -923.81x + 4.9302 Figure 6: Shows a linearized plot of Voltage vs Time for the...
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This note was uploaded on 01/21/2013 for the course PHYSICS 4A 4AL taught by Professor Yu during the Spring '13 term at UCLA.
- Spring '13