edit for faraday prelab

1 files changed, 14 insertions, 3 deletions

diff --git a/faraday_prelab.tex b/faraday_prelab.tex
index dd9f1d7..d20324d 100644
--- a/faraday_prelab.tex
+++ b/faraday_prelab.tex
@@ -36,15 +36,26 @@ Using Eq.(2) roughly estimate the value of the expected rotation angle for $B\ap
 Examine Eq.(4) to find the value of the angle $\theta$ that will provide
 maximum useful signal for measuring $\phi$.
 
-Hint:  If you  are having  trouble, try  this: for  each of  the angles  in
+Hint 1: Every time I hear maximum or minimum, I think about derivatives.
+
+Hint 2:  If you  are having  trouble, try  this: for  each of  the angles  in
 question 1  compute the  numerical value  of the two  terms in  equation 4,
 assuming $I_0=1.0$, and your value of $\phi$ from part 2. Is the intensity
 $I$ in equation 4 sensitive to the value of $\phi$ for each of those angles? Compute
 for other angles  of your choice. How  do we adjust $\theta$  to maximize the
 useful signal?
 
-\section*{4. Error analysis}
-In this experiment you will be determining the error in the amplitude of an oscillating signal using its digitized form, recorded by an oscilloscope. A sample yellow trace, shown in Fig.(3), depicts the change in the signal voltage as a function of time. What would be a good measure of the uncertainty in its amplitude for such a measurement?
+\section*{4. The source of polarization}
+
+The previous questions assumed that there are two polarizers in the system.
+But, figure  2 in the  manual shows only  one. This experiment  cannot work
+with just one polarizer. So, where is the other one?
+
+Hint: read the lab manual carefully.
+
+
+% \section*{5. Error analysis}
+% In this experiment you will be determining the error in the amplitude of an oscillating signal using its digitized form, recorded by an oscilloscope. A sample yellow trace, shown in Fig.(3), depicts the change in the signal voltage as a function of time. What would be a good measure of the uncertainty in its amplitude for such a measurement?