typos fixed, thanks to Michael

1 files changed, 9 insertions, 9 deletions

diff --git a/pe-effect.tex b/pe-effect.tex
index f81d5b7..976511a 100644
--- a/pe-effect.tex
+++ b/pe-effect.tex
@@ -93,17 +93,17 @@ lines in both the first and the second diffraction orders on both sides. Keep in
 Often the first/second order lines on one side are brighter than on the other - check your apparatus and
 determine what orders you will be using in your experiment.
 
-After that, install the $h/e$ Apparatus and focus the light from the Mercury Vapor Light Source onto the slot in
-the white reflective mask on the $h/e$ Apparatus. Tilt the Light shield of the Apparatus out of the way to
-reveal the white photodiode mask inside the Apparatus. Slide the Lens/Grating assembly forward and back on its
+After that, install the $h/e$ apparatus and focus the light from the mercury vapor light source onto the slot in
+the white reflective mask on the $h/e$ apparatus. Tilt the light shield of the apparatus out of the way to
+reveal the white photodiode mask inside the apparatus. Slide the Lens/Grating assembly forward and back on its
 support rods until you achieve the sharpest image of the aperture centered on the hole in the photodiode mask.
-Secure the Lens/Grating by tightening the thumbscrew. Align the system by rotating the $h/e$ Apparatus on its
+Secure the Lens/Grating by tightening the thumbscrew. Align the system by rotating the $h/e$ apparatus on its
 support base so that the same color light that falls on the opening of the light screen falls on the window in
 the photodiode mask, with no overlap of color from other spectral
- lines. Return the Light Shield to its closed position.
+ lines. Return the light shield to its closed position.
 
 Check the polarity of the leads from your digital voltmeter (DVM), and connect them to the OUTPUT terminals on
-the $h/e$ Apparatus.
+the $h/e$ apparatus.
 
 
 \section*{Experimental procedure}
@@ -113,7 +113,7 @@ the $h/e$ Apparatus.
 \section*{Part A: The dependence of the stopping
     potential on the intensity of light}
 \begin{enumerate}
-\item Adjust the $h/e$ Apparatus so that one of the blue first order spectral lines falls upon the opening of the mask of the photodiode. 
+\item Adjust the $h/e$ apparatus so that one of the blue first order spectral lines falls upon the opening of the mask of the photodiode. 
 \item Press the instrument discharge button, release it, and observe how much time\footnote{Use the stopwatch feature of your cell phone. You don't need a precise measurement.} is required to achieve a stable voltage.
 
 \item It's important to check our data early on to make sure we are not off
@@ -156,11 +156,11 @@ The mercury lamp visible diffraction spectrum.}
 \section*{Part B: The dependence of the stopping potential on the frequency
     of light}
 \begin{enumerate}
-\item You can easily see the five brightest colors in the mercury light spectrum. Adjust the $h/e$ Apparatus so that the 1st order yellow colored band falls upon the opening of the mask of the photodiode. Take a quick measurement with the lights on and no yellow filter and record the DVM voltage. Do the same for the green line and one of the blue ones. 
+\item You can easily see the five brightest colors in the mercury light spectrum. Adjust the $h/e$ apparatus so that the 1st order yellow colored band falls upon the opening of the mask of the photodiode. Take a quick measurement with the lights on and no yellow filter and record the DVM voltage. Do the same for the green line and one of the blue ones. 
 
 \item Repeat the measurements with the lights out and record them (this will require coordinating with other groups and the instructor).  Are the two sets of measurements the same?  Form a hypothesis for why or why not.
 \item Now, with the lights on, repeat the yellow and green measurements with the yellow and green filters attached to the h/e detector. What do you see now?  Can you explain it? (Hint: hold one of the filters close to the diffraction grating and look at the screen).
-\item Repeat the process for each color using the second order lines.  Be sure to use the the green and yellow filters when you are using the green and yellow spectral lines.
+\item Repeat the process for each color using the second order lines.  Be sure to use the green and yellow filters when you are using the green and yellow spectral lines.
 
 \end{enumerate}