ame: ________________________
Exam 3--PHYS 202--S11
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. A convex lens has a focal length of 20 cm. The object is located 10 cm to the left of the lens. Which of these
describes the image?
a.
b.
____
real, inverted, and to the left of the lens
d. virtual, upright, and to the left of the lens
e. virtual, inverted, and to the left of the
virtual, upright, and to the right of the
lens
lens
c. real, inverted, and to the right of the lens
2. This figure shows a mirror along with the object and the image the mirror forms. What kind of mirror has
produced this image?
a.
b.
____
____
____
concave
either convex or concave, depending on
the object distance
3. What is the magnification of a flat mirror?
c.
d.
flat
convex
a. 1/2
d. -1
b. 2
e. it depends on the object distance
c. 1
4. Most cameras have an aperture to block the outer edges of the lens. What is the purpose of this aperture?
a. to protect the film from cosmic rays
c. to reduce the effects of spherical
aberration
b. to eliminate chromatic aberration
d. to reduce the amount of harmful UV
radiation from entering your eye
5. Which of these physical phenomena are the cause of a mirage?
a.
b.
reflection
interference
c.
d.
1
refraction
diffraction
____
6. Consider these two waves. What type of interference occurs when the two waves combine?
____
7.
____
8.
____
9.
____ 10.
a. constructive interference
c. just partial destructive interference
b. destructive interference
d. no interference
In the previous figure, by what amount are the two waves out of phase?
a. ½ λ
c. 1 λ
b. ¼ λ
d. 0λ
LIGO is an observatory that is based on which of these devices?
a. an interferometer
d. a photomultiplier tube
b. a bolometer
e. a telescope
c. a microscope
In a double-slit experiment, when the wavelength of the light is increased, the interference pattern ...
a. disappears
c. stays the same
b. shrinks together
d. spreads out
In a single-slit experiment, what path difference have the waves from each slit traveled to give a minimum at
the indicated position?
a.
b.
½λ
1½ λ
c.
d.
2
0λ
1λ
____ 11. Consider the superposition of these 2 waves. Which of the choices represents the interference pattern?
a.
c.
b.
d.
____ 12. A mass on a spring is pulled to x=A and released. After a time of one period, what distance has the mass
travelled?
a. 2A
d. A
b. ½A
e. ¼A
c. 4A
____ 13. Consider this graphical representation of simple harmonic motion. When a particle is at point A, its velocity
and acceleration are...
a.
b.
velocity is negative and acceleration is
negative
velocity is positive and acceleration is
positive
c.
d.
3
velocity and acceleration are both
positive
velocity and acceleration are both
negative
____ 14. Consider these plots of displacement versus time for an object in simple harmonic motion. How do their
frequencies compare?
a.
frequency of Object A is larger than the c. both have the same frequency
frequency of Object B
b. frequency of Object A is smaller than the d. cannot tell from these graphs
frequency of Object B
____ 15. 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.
1
λ
4
c.
b.
1λ
d.
4
1
λ
2
1
1 λ
2
Problem
16. (20 pts)
(a) How far from a 1.2-m-focal-length convex mirror should you place an object in order to
get an upright image ½ the size of the object?
(b) Where will the image be?
.
5
17. (15 pts) Consider this optical system. What is the magnification of the final image? Is the image real or
virtual? Is the image upright or inverted?
M=____________
Real or Virtual?
Upright or inverted?
6
18. (15 pts) Green light at 510 nm is diffracted by a grating with 5000 lines per cm.
a) On a screen 12 meters away, what is the distance between the central fringe and the
3rd bright fringe?
b) Sketch the diffraction pattern that is visible on the screen. Show (& calculate) the
appropriate number of orders.
.
7
19. (20 pts) a) Write an expression for the position of simple harmonic motion of a mass of 1.3
kg on a spring with spring constant 1200 N/m. The maximum velocity, which is 1.5 m/s, of
the spring occurs at t=2.0 seconds.
b) Calculate the period of the motion.
-
8
ID: A
Exam 3--PHYS 202--S11
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
D
A
C
C
C
B
A
A
D
D
A
C
A
B
A
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
PROBLEM
16. ANS:
.
PTS: 1
17. ANS:
.
PTS: 1
18. ANS:
.
PTS: 1
19. ANS:
PTS: 1
1