PASCO OS-8536 OPTICS TABLE - Manual (Page 8)

4
Optics Table 012-06557A
For the second trail let the single ray from the Light Source strike the curved surface of the Cylindrical Lens.
(Just rotate the Ray Table 180°.) Start at 0 (zero) degrees. Rotate the Ray Table to each Angle of Incidence
2
(the
values you listed in Table 1.1 as Angle of Refraction
1
). Record the corresponding values as the Angle of Refrac-
tion
2
.
1. Using your values for Incidence
1
and Refraction
1
, determine the index of refraction for the acrylic from which
the Cylindrical Lens is made. Remember, Snell’s Law describes the relationship between the angles of inci-
dence and refraction and the indices of refraction:
n
air
sin Incidence
1
= n
acrylic
sin Refraction
1
. (Assume that the index of refraction for air is 1.0.)
n
acrylic
= ___________________________________________________________.
2. Using your values for Incidence
2
and Refraction
2
, redetermine the index of refraction for the acrylic from which
the Cylindrical Lens is made.
n
acrylic
= __________________________________________________________.
3. Is the Law of Refraction the same for light rays going in either direction between the two media?
4. Does the principle of optical reversibility hold for Reflection as well as Refraction? Explain.
Table 1.1 Data
Ray Incident on: Flat Surface Curved Surface
Angle of: Incidence
1
Refraction
1
Incidence
2
Refraction
2
0°
10°
20°
30°
40°
50°
60°
70°
80°
Record data.
Without disturbing the alignment of the Cylindrical Lens, rotate the Ray Table and set the angle of incidence to
the values listed in Table 1.1. Enter the corresponding angle of Refraction in the table in two columns: Angle of
Refraction
1
and Angle of Incidence
2
. (In other words, for the second trial, let Angle of Incidence
2
be the value
you measured for Angle of Refraction
1
).