deletions | additions       diff --git a/subsection_Lock_in_Method_A__.tex b/subsection_Lock_in_Method_A__.tex  index b7b2b66..a1f7ed9 100644  --- a/subsection_Lock_in_Method_A__.tex  +++ b/subsection_Lock_in_Method_A__.tex 
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A third method for finding the Verdet constant of a material involves using a lock-in amplifier to better read the signal from the photodiode.   %The lock-in we used was set at a frequency range was 100 Hz and the fine frequency range adjustment was 10 Hz.   The lock-in amplifier had a gain of $10$, the pre-amplifier a gain of $500$, the bandpass filter a gain of 2, $2$,  and the low pass filter a gain of 1. $1$.  We used a function generator to sinusoidally drive the voltage going into the solenoid, using a frequency of 100 $100$  Hz. We varied the RMS value of the AC voltage which was driving the solenoid and recorded the RMS value of the corresponding varying photodiode voltage. The big idea of the calculation associated with this method is illustrated in Equation \ref{bigidea} :  \begin{equation}  \label{bigidea}