Document

Physics 221: Exam 1, Spring-2010
Name:
Section. No:
NOTE: Problems 1 and 2 are each worth 18 points and 3-6 are each worth 16 pts
1. A lighted candle is placed 36.0 cm in front of a converging lens of focal length f
1 13 cm which in
turn is 56 cm in front of another converging lens of focal length f
2 = 16.0 (see Fig. below)
a) Draw a ray diagram to locate the final image
b) Now calculate the location of the fmal image after passing through both lenses
c) Is the fmal image real or virtual?
d) What is the magnification of the fmal image?
e) Is it erect or inverted?
fi
=
13cm
f2=l6cm
I
-
c(tS
3
‘3
I
‘-
“4’??
h)
c-)
-zOcO3’14 )
4
?.O5C
1
2A
fI
-
fl12t
d—
________—.
—
_fci
/fl’6’ri 1sT
C
—
—
“I,
m”
) ev-c-t
£i,,’
,O
1
2. An object is moving toward a converging lens of focal length f with a constant speed v
0 such that its
distance so from the lens is always greater than f.
1 of the image as a function of s
a) Determine the velocity v
, f, and vo.
0
b) Which direction (towards or away from the lens) does the image move?
c) For what so does the image’s speed equal the object’s speed?
1
C.
LL
I
sI-c
Si
a fC€.-rti
8
dS
fe
J’
_j,’L
c-rci,
k)
c)
tk’
fri-.ç
3. A thin oil slick (no = 1.50) floats on water (n = 1.33). When a beam of of white light strikes the film at
normal incidence from air, the only enhanced reflected colors are red (650 nm) and violet (390 nm). From this
information, deduce the (minimum) thickness of the oil slick.
pi
ç-i, 1
/
F-
-k’
,fr
1
c-Z
•‘—:)
t-_L ‘•)
2*
=.
(m
-“)
‘is
2t
I’S-
I
:
-I--i
I’Vj’’
39’,
0
—
vøj .1-
1ly;,jZ
,’j- I
12
1-
32Snn-?
01 *-1
2h
2_ h’v2 I— 1
3
4
L
4. In a double slit experiment, the distance between the slits was forty wavelengths and this was five times the
slit width. Compare (as a ratio) the intensity of the third order interference maximum with that of the zero-order
maximum.
ci
2
_
1
c_
)43
?-c-ya-
D
L-d7T
d
1c
C-
/(Z7
1—
I
C
5—
J
5. Two polarizers A and B are aligned so that their transmission axes are vertical and horizontal respectively.
A third polarizer is placed between these two with its axis aligned at an angle 0 with respect to the vertical.
Assuming vertically polarized light of intensity 1 is incident upon polarizer A,
a) Find an expression for the light intensity I transmitted through this three-polarizer sequence( Express your
answer in terms of Jo and 0).
b) Calculate dI/dO then use it to find the angle that maximizes I.
A
2.
A,’
;n,•Y
Ve/t1’tY
A.
1 c
)Dc --L
Sld-
£0
4
2.
/VoW
Ei)
1
jv
7€i.)fl7
=
=
1
l
7
krD
—
4.L-4
e
6. When yellow sodium light, A. = 589 nm, falls on a diffraction grating, its first-order peak on a screen
66.0 cm away falls 3.32 cm from the central peak. Another source produces a first-order line 3.71 cm
from the central peak.
a) What is its wavelength?
b) How many lines/cm are on the grating?
8 -/-V2L
F
I
—
“1
e
p
I)
D
ci
2.
‘-I,.,
/Lf
3
1
>1 i,,,
J)
F
3,7/
EE_
/.i7fi’

Download Report