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The voltage drop across a resistor and the current passing through the resistor were measured and compared to the nominal value of resistance obtained from the colored bands of the resistor. We found reasonable agreement; the greatest source of error was the imprecision of the ammeter, which limited our accuracy to about 2%. Furthermore, since all resistances calculated from the measured current were about 4% low, we suspect that the calibration of the ammeter is off by about 4%.
Kirchhoff's laws were investigated for a simple resistor circuit and found to hold within our experimental uncertainty of 2%, again limited by the precision of the ammeter. We note that when making current measurements, it is necessary to insert the ammeter in series with the element whose current one is measuring.
We investigated the behavior of R-C circuits using a square-wave generator and oscilloscope. The oscilloscope, when properly triggered by a repetitive signal of interest, displays the signal in a plot of voltage versus time. By adjusting the horizontal (temporal) and vertical (voltage) scales, a useful pictoral representation of a time-changing signal can be easily displayed. We used the plot to estimate the RC-time of the R-C circuit, but the value obtained had a high uncertainty (20%) because we failed to record the limiting value of voltage obtained after several time constants. It did, however, agree satisfactorily with the computed value (theoretical value = 1.05 +/- 0.05 ms; experimental value = 1.25 +/- 0.25 ms).