PASCO OS-8170A Brewster’s Angle Accessory - Manual (Page 6)

Brewster’s Angle Accessory Model No. OS-8170A
6
®®
where n is the index of refraction
of the medium and
 is the angle of
the ray from the normal.
When the angle of the incident ray
is equal to Brewster's angle,
p
,
n
1
sin
P
= n
2
sin
2
(2)
and since
P
+
2
= 90
o
,
2
= 90
o
-
P
, and
sin
2
= sin(90
o
-
P
) =
sin90
o
cos
P
- cos90
o
sin
P
=
cos
P
Substituting for sin
2
in Equation (2) gives n
1
sin
P =
n
2
cos
P
Therefore, (3)
Setup Instructions
Assemble the Spectrophotometer Base
1. Attach the Spectrophotometer Base at
one end of an Optics Bench.
2. Attach the Spectrophotometer Degree
Plate to the Base, but align the Degree
Plate “backwards”; that is, line up the
180 degree mark on the Degree Plate
with the index line on the Base.
3. Attach the Spectrophotometer Arm to
the Degree Plate.
(For instructions on setting up the
Spectrophotometer parts, see the
Educational Spectrophotometer
Manual. You can download a PDF file
of the manual from the PASCO web
site. Go to the page that shows the
OS-8539 and click the “Manual” tab.)
Figure 2: Polarization of Unpolarized ligh t

 
 
 
 
 

  
n
2
n
1
------

P
tan =
Spectrophotometer
Base
Spectrophotometer
Degree Plate
Spectrophotometer
Arm
Line up the 180
degree mark
Index
line
Figure 3: Assemble the Spectrophotometer Base,
Degree Plate, and Arm