PH113 Physics III
Test III
Spring 1996/97
Name _________________________
(Please print in UPPER CASE BLOCK letters)
Section (hour) __________________
No books or paper notes are allowed. A one page formula sheet is attached as the last page of this test. It may be
removed and need not be handed in. You may use your laptop and any resources residing on your hard drive. This
includes Maple and Working Model. No network connections are allowed. Any student with a physical
connection between the computer and the network outlet during the test will receive a zero on the test.
Show all your work. No credit will be given for answers appearing without supporting calculations. Partial credit
may be awarded based on clarity and completeness of solution.
1. An object is placed 20.0 cm in front of a convex mirror with a radius of curvature R = 80.0
cm.
(a) Located the image by making a careful ray diagram using the figure below. Include at least
three (3) special rays on you diagram.
(b) Use the mirror equation to locate the exact position of the image.
(c) Characterize the image. (real or virtual) (upright or inverted)
(d) If the original object is 5.00 cm high, how large is the image?
PH113 Physics III
Test III
Spring 1996/97
Name _________________________
(Please print in UPPER CASE BLOCK letters)
2. A light ray enters a 30E-60E-90E prism at normal incidence to the short leg as shown in the
diagram below. The prism is constructed of glass with refractive index n = 1.50 for the
wavelength of the light used. Carefully trace the ray’s path through the prism until the majority of
the light exits the prism. In you answer show the angle from the normal and the face from which
the light exits.
60
90
30
PH113 Physics III
Test III
Spring 1996/97
Name _________________________
(Please print in UPPER CASE BLOCK letters)
3. A thin biconvex lens is formed of glass with an index of refraction of 1.510 for light of
wavelength 400 nm. Radii of curvature of the front and back surfaces are 0.500 m and 0.600 m,
respectively.
(a) (5 points) Sketch the lens shape.
(b) (20 points) What is the focal length of this lens?
PH113 Physics III
Test III
Spring 1996/97
Page 4 of 4
Name _________________________
(Please print in UPPER CASE BLOCK letters)
4. A diverging lens (f1 = -10.0 cm) is separated by 14.0 cm from a converging lens (f2=12.0 cm)
as shown in the figure below. A object 5.00 cm high is placed 15.0 cm to the left of the first lens.
f1
15 cm
f2
f1
f2
14 cm
(a) Using (i) a ray diagram showing at least three rays and (ii) the thin-lens equation, find the
position and character of the image formed by the FIRST lens only. Characterize it as real or
virtual, upright or inverted.
(b) Now, using (i) a ray diagram showing at least three rays and (ii) the thin-lens equation, find
the position of the image formed after light from the object has passed through both lenses.
Characterize the final image as real or virtual, upright or inverted.
(c) Calculate the overall magnification of the two-lens system.