PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM - Manual (Page 22)

Introductory Optics System 012-02744K
®
16
Now let the incident ray strike the curved surface of the lens. (Just rotate the Ray Table 180°.)
The internal angle of incidence for the flat surface of the Cylindrical Lens is shown in Figure 5.2.
Set this angle of incidence to the values you have already listed in the table (Incidence
2
). Record
the corresponding angles of refraction (Refraction
2
).
➀ Using your collected values for Incidence
1
and Refraction
1
, determine the index of refraction for
the acrylic from which the Cylindrical Lens is made. (As in experiment 4, assume that the index
of refraction for air is equal to 1.0.)
n
1
=
______________________________________________________________________.
➁ Using your collected values for Incidence
2
and Refraction
2
, redetermine the index of refraction
for the acrylic from which the Cylindrical Lens is made.
n
2
=
______________________________________________________________________.
➂ Is the Law of Refraction the same for light rays going in either direction between the two
media?
____________________________________________________________________.
➃ On a separate sheet of paper, make a diagram showing a light ray passing into and out of the
Cylindrical Lens. Show the correct angles of incidence and refraction at both surfaces traversed
by the ray. Use arrow heads to indicate the direction of propagation of the ray. Now reverse
the arrows on the light ray. Show that the new angles of incidence and refraction are still
consistent with the Law of Refraction. This is the principle of optical reversibility.
➄ Does the principle of optical reversibility hold for Reflection as well as Refraction? Explain.
_________________________________________________________________________.
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°
90°
Table 5.1 Data