ame: ________________________
Exam 3--PHYS 102--S10
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. At an intersection of hospital hallways, a convex mirror is mounted high on a wall to help people
avoid collisions. The mirror has a radius of curvature of 4.0 m. A patient is 4.0 m from the mirror.
What is the magnification of the image created by the mirror?
____
a.
3
c.
b.
-1
d.
1
2
1
3
2. A dentist uses a mirror to examine a tooth that is 2.00 cm in front of the mirror. The image of the
tooth is formed 4.0 cm behind the mirror. Determine the mirror's focal length.
a.
b.
0.2 cm
8.0 cm
c.
d.
1
1.33 cm
4 cm
____
3. A 2.00-cm-high object is placed 3.00 cm in front of a concave mirror. If the image is 5.00 cm high
and virtual, what is the image distance of the image?
a.
b.
____
-1.4 cm
-7.5 cm
c.
d.
3.2 cm
-1.2 cm
4. A person uses a convex lens that has a focal length of 12.5 cm to inspect a gem. The lens forms a
upright image. Is the image real or virtual?
a.
b.
____
virtual
real
c.
d.
neither, no image is formed
not enough information
5. A concave lens has a focal length of 10.0 cm. If the object is located at 10 cm to the left of the lens,
where is the image?
a.
b.
5 cm to the left of the lens
there is no image
c.
d.
2
20 cm to the left of the lens
10 cm to the right of the lens
____
____
6. You focus on an object that is very far away. Then, the object moves closer to you. The focal length of your
eye lens has...
a. increased
c. stayed the same
b. decreased
7. This figure shows a two-lens system. If the object is a distance of p=30 cm to the left of lens 1. What is the
location of the final image created by lens 2?
____
a. 47 cm to the right of lens 2
c. 33 cm to the right of lens 2
b. 60 cm to the left of lens 2
d. 50 cm to the right of lens 2
8. What happens to the image size in a flat mirror when you move away from the mirror?
____
a. it gets bigger
c. it remains the same size
b. it gets smaller
d. it depends on the size of the mirror
9. If you want to set fire to a pile of leaves with a lens, which of these is the best one to use?
a.
b.
convex lens
concave lens
c.
d.
3
neither of these
both of these will work
____ 10. The following figure shows the positions of a mirror, the object, and the image. What type of mirror would
produce the image as shown?
a. concave mirror
c.
b. convex mirror
d.
____ 11. Lenses experience which of these aberrations:
flat mirror
Either concave or convex
I. Spherical Aberration
II. Chromatic Aberration
a.
b.
I
II
c.
d.
I & II
neither of these
____ 12. A laser beam (λ= 500 nm) is incident on two slits 0.400 mm apart. What is the distance between the
central fringe and the first bright fringe on a screen 5 m away?
a.
b.
1x10-6 mm
3.1 mm
c.
d.
4
6.25 mm
there is no interference pattern
____ 13. A double slit of width 0.02 mm is illuminated by a laser with wavelength of 500 nm. How many fringes are
present on the screen (include both sides of the pattern and the central fringe)?
a.
b.
81
160
c.
d.
80
there are an infinite number of fringes in
the pattern
____ 14. Helium -neon laser light (λ = 632.8 nm) is sent through a 0.300-mm-wide single slit. What is the
width of the central maximum on a screen 1.00 m from the slit?
a. 4.2 mm
c. 0.3 mm
b. 1.0 m
d. 2.1 mm
____ 15. A diffraction grating has 3000 lines per centimeter. What is the slit spacing, “d,” for this grating?
a.
b.
3000 m
1.2x10-4 m
c.
d.
5
3.3x10-6 m
3.1x10-3 m
____ 16. A diffraction grating has 3000 lines per centimeter. Light incident on the diffraction grating shows its first 2
orders at angles of 12.0° and 24.7°. What is the wavelength of the light?
a. 300 nm
c. 690 nm
b. 720 nm
d. 1400 nm
____ 17. The following figure shows a Michelson interferometer. If the source of light is a laser of wavelength λ,
what is the smallest distance the translating mirror must move (∆x) in order to see a shift on the detector of 1
fringe (ie. where there was once a dark fringe, there would now be a bright fringe)?
a.
b.
1
λ
2
1
1 λ
2
c.
1
λ
4
d.
1λ
6
____ 18. The following figure shows the interference pattern produced by a diffraction grating. What is the pathlength
difference of the two waves that are incident to create the dark fringe indicated by the arrow?
1
λ
c. 1λ
4
1
1
b.
λ
d. 1 λ
2
2
____ 19. In a single slit diffraction pattern, what would you do to make the central bright spot narrower?
a.
a. decrease the slit width
b. move the screen further away
____ 20. These 2 waves are:
a.
b.
in phase
360° out of phase
c.
d.
increase the wavelength
increase the slit width
c.
d.
180° out of phase
90° out of phase
7
____ 21. What caused the diffraction pattern in this picture?
a.
light from a light bulb incident on a
c. light incident on a circular object (such
double slit
as a penny)
b. a laserbeam incident on a single slit
d. none of these
____ 22. Place these stages in the proper order for the formation of a star:
1.
2.
3.
4.
Star
Protostar+disk
Star-forming cloud
Star-forming core
a. 3, 2, 4, 1
c. 3, 4, 2, 1
b. 4, 3, 2, 1
d. 2, 3, 4, 1
____ 23. Why is star-formation activity more readily apparent in infrared observations than in visible images?
a.
visible light is obscured by the dust in
star-forming regions
c.
b.
infrared light can pass through dust
unattenuated
d.
8
star-forming regions emit radiation
mostly in the infrared part of the
spectrum
all of these
____ 24. This plot has reddening and distance for a group of stars. Which of these statements best describes the
location of the stars in the box on the plot?
a. beside a star-forming core
b. behind a star-forming core
____ 25. The answer to this question is “A.”
a. A
b. B
c.
d.
in another galaxy
in front of a star-forming core
c.
d.
C
D
9
ID: A
Exam 3--PHYS 102--S10
Answer Section
MULTIPLE CHOICE
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