True-false questions are worth 2 points each, three-choice multiple
choice questions are worth 3 points each, five-choice multiple choice
questions are worth 6 points each. The maximum possible score is 97;
the mean score was 69.6; the median was 73. The exam period was 75
minutes. Click here to see page1
page3 of the formula sheet that came
with the exam.
Some helpful information:
• A reminder about prefixes: p (pico) = 10-12; n (nano) =
10-9; μ (micro) = 10-6; m (milli) =
10-3; k (kilo) = 10+3; M or Meg (mega) =
10+6; G or Gig (giga) = 10+9.
(a) 14 cm
(b) 34 cm
(c) 58 cm
(d) 72 cm
(e) 130 cm
(a) 9 cm
(b) 13 cm
(c) 29 cm
(d) 47 cm
(e) 65 cm
In the diagram, the horizontal dashed lines indicate horizontal axes
(x-axes). The angles θ1 = 80°,
θ2 = 40° and θ3 =
60° are the angles of transmission axes of three polarizers; these
angles are measured with respect to the positive x-axis, and are not
necessarily drawn to scale. Unpolarized light of average intensity 4
watts per square meter is incident along an axis perpendicular to these
What is the average intensity of light emerging from the third
(a) 0.063 W/m2
(b) 0.29 W/m2
(c) 0.58 W/m2
(d) 1.04 W/m2
(e) 2.1 W/m2
(a) 9 × 10-8 T
(b) 1.3 × 10-7 T
(c) 1.8 × 10-7 T
(a) Yes, the light intensity in this case does not equal the
intensity when θ2 = 40°.
(b) No, the intensity is the same when θ2 = 220°
as when θ2 = 40°.
(a) Light might or might not emerge from the third polarizer,
depending on θ2.
(b) Yes, light always emerges from the third polarizer, regardless of
(c) No, no light emerges from the third polarizer, regardless of
The diagram shows a real object and its image for a lens depicted by the
vertical line. (Details of the shape of the lens are not revealed.)
There is a focal point along the principal axis to the left of the
lens. Where is it located?
(a) to the left of the object
(b) between the object and the image
(c) between the image and the lens
(a) f > 0
(b) f < 0
A rectasngular glass prism with index of refreaction n = 1.6 is
surrounded by air. Light enters from the left. Inside the prism, the
light makes an angle φ = 23° with respect to the top
surface of the prism.
What is the angle θ made by the light with respect to
the left face?
(a) Some of it will escape through the top surface of the prism.
(b) None of the light can escape through the top surface of the prism.
(a) 1 mm
(b) 1 cm
(c) 10 cm
(d) 1 m
(e) 10 m
This shape is a (highly exaggerated) depiction of a corrective lens.
The dashed line shows the principal axis.
Consider a ray of light parallel to the principal axis, striking this
lens from the left. What effect does each surface have on this incident
(a) The ray bends toward the principal axis as it enters the
lens, and toward the principal axis even more as it exits.
(b) The ray bends away from the principal axis as it enters, and toward the
principal axis as it exits.
(c) The ray bends toward the principal axis as it enters the lens and away
from the principal axis as it exits.
(a) It corrects farsightedness only.
(b) It corrects nearsightedness only.
(c) It serves as a magnifier only.
(d) It can be used to correct for farsightedness and serve as a magnifier (but nothing else).
(e) It can be used to correct for nearsightedness and serve as a magnifier (but nothing else).
(a) -11 cm
(b) +11 cm
(c) +50 cm
Two lenses, with focal lengths f1 = -10 cm and
f2 = 8 cm, are separated by a distance L. (The
diagram shows the lenses as flat plates to obscure their shapes.)
You hold a real object at x = 5 cm in front of the first lens.
The second lens produces a real image 28 cm away from that lens. Under
these circumstances, what is L?
(a) 1.2 cm
(b) 7.9 cm
(c) 11.2 cm
(d) 14.5 cm
(e) 21.2 cm
(a) -1.67 mm
(b) -0.67 mm
(c) +0.4 mm
(d) +0.67 mm
(e) +1.67 mm
Water (index of refraction n = 1.33) sits in the bottom of a
glass cup. The glass underneath the water is thicker near the edge; the
water is deepest in the center. The index of refraction of the glass is
n = 1.53. Light shines downward onto the water from above.
For what thinnest (non-zero) layer of water are reflections of yellow
light (λ = 580 nm) extinguished?
(a) 91.7 nm
(b) 109 nm
(c) 184 nm
(d) 218 nm
(e) 275 nm
(a) 8.9 mm
(b) 8.9 cm
(c) 18 cm
(d) 97 cm
(e) In this situation, there will be no fifth-order bright spot.
(a) 0.04 mm
(b) 0.08 mm
(c) 0.16 mm