Physics 41 Quiz 15 CH 23 Fall 2016
Name:______________________________
T W TH
Short Problems (2 points each) Show work. Neatness Counts. Assume 3 sig figures. Box Final answers.
1. A diver in the water shines an underwater searchlight at the surface of a pond (n = 1.33). At what angle (relative to
the normal) will the light be totally internally reflected? Sketch and label the situation.
a.
b.
c.
d.
e.
47
41
51
58
49
2. A ray of light is incident on a glass/water interface at the critical angle
as shown. Find the refraction angle (in degrees) the ray emerges from the
liquid into air (theta 5)
a.
b.
c.
d.
e.
29
48
61
36
68
3. A fisherman in a stream 39 cm deep looks downward into the water and sees a rock on the stream bed. How deep
does the stream appear to the fisherman? The index of refraction of the water is 1.33. Sketch and label.
A) 29 cm
B) 52 cm
C) 33 cm
D) 45 cm
4. A ray of light consisting of blue light (wavelength 480 nm) and red light (wavelength 670 nm) is incident on a thick
piece of glass at 80°. What is the angular separation between the refracted red and refracted blue beams while they are
in the glass? (The respective indices of refraction for the blue light and the red light are 1.4636 and 1.4561.) Sketch
and label the situation.
A) 0.27°
B) 0.33°
C) 0.36°
D) 0.46°
E) 0.54°
5. Monochromatic light ( = 500 nm) is incident on a soap bubble (n = 1.40). How thick is the bubble (in nm) if
destructive interference occurs in the reflected light? Draw the situation. Derive and or explain, justify your answer.
a.
b.
c.
d.
e.
102
179
54
1
89
The Long Problem. 10 points. NEATNESS COUNTS! BOX final numerical answers!!
A narrow beam of white light enters an equilateral prism made of crown
glass at 45.0 degrees incident angle as shown.
a. At what angle does the red (660.0 nm) component of the light emerge
from the prism relative the normal of the right side? The index of
refraction for red light in crown glass is 1.512 .
b. What must be the incident angle on the left side to produce total internal
reflection in the prism on the right side?
Assume the beam is incident at the midpoint on the left side.
Redraw the prism large enough to have room to label rays and angles. You need to do it TWICE for each
question!