Ning Zhu edited In_addition_to_the_uncertainty__.tex  over 8 years ago

Commit id: 9edea601af932ba67b20db948270586da5980cde

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In addition to the uncertainty coming from the measurements, the fit of the data points might also result in some uncertainties. In order to see whether our fits in Figure \ref{fig:directmethoddata} and Figure \ref{fig:VB} are reliable or not, we calculated the $\tilde{\chi}^2$ for those fits. Based on our calculation, we can conclude that our obtained Verdet constants are obtained from accurate fits from our data. \\  For the fits shown in Figure \ref{fig:directmethoddata}, we obtained a $\tilde{\chi}^2=1.150$ for the fit of our data with no field applied,and $\tilde{\chi}^2=1.206$ for the fit of our data with a magnetic field applied.\\  For the fit shown in Figure \ref{fig:VB}, we obtained a $\tilde{\chi}^2=1.018$.\\  As a $\tilde{\chi}^2\approx1$ indicates a good fit, we can conclude that those fits are reliable. Therefore, we can assume that our curves fit our data well, giving us reasonable results for Verdet Constant.  %The issues that had the most impact on our data occurred with the lock-in method. We initially took data for currents that were much too high for our solenoid, causing possible temperature effects in our data. We also saturated the lock-in amplifier without realizing it. For future experiments, even more accuracy could be achieved by measuring in smaller angle increments around the angle that was found to be most sensitive. It would also be interesting to test the methods we have used here using a material with a much smaller Verdet constant.