NAME
1. How many 100 W lightbulbs can you use in a 120 V circuit without tripping a 15 A circuit
breaker.
a.
b.
1
6
Find the charge on the 4 pF capacitor in the following circuit.
3 . A hydrogen atom initially in its ground state (n = 1) absorbs a photon and ends up in the state for
which n =3. What is the wavelength of the absorbed photon?
a.
b.
c.
d.
e.
10 nm
50 nm
75 nm
nm
165nm
,
z /3,6
E3
e V
(1.3.Lni.S7)ev
.k.
/I
6~ A = h c
E,=
sb/*
-
= 12- 1 ev
(. Q& lo-?*
d
/A1c
/,S/eV
/3-6eV3%
z
/a
=
wrw
v
L o , r f
ev
h Jo~k
w
4.
<
&
What is the current through the 8.00 fi resistor?
c.
d.
e.
4.3 A
7.6 A
11.9A
4R
12 v
-z
12v
6lL
52A
NAME
5. A cube with an edge of length 1 = 0.04 m is placed in a uniform magnetic field ,throughout,the
region that has components B, = 0, By = 4 T and Bz = 3 T. Find the flux through the top face of the
cube.
a.
b.
Zero
0.0064 ~m~
04048 TmLJ
0.12TmL
0.16 ~m~
6
d.
e.
6. The half-life of an isotope of phosphorus is 14 days. If a sample contains 3 . 5 4 ~ 1 0such
' ~ nuclei,
what is its activity?
a.
G b .
c.
d.
e.
=
1.85x108Bq
2.03~10%
1 . 7 2 10"
~ Bq
1 . 7 5 ~ 1 0Bq
'~
4 . 8 5 ~ 1 0~q~ ~
AM
bdt
/
I=
IL,
fkCV
-TGi
kco%&
8640ofi
~
I Y GC=DO?~@
k Z I ~= L
t
R-
L
C
e
I ~ ( L ) ~ ~ g ~3 e~0 3' s /~0 '~o $! - -~
1209600
7. A cylindrical piece of insulating material is placed in an external electric field, as shown. The net
electric flux passing through the surface of the cylinder is
a.
IZ
negative
~ m is used to determine the position of an electron to within
8, Light with a wavelength of 4 . 2 10'~
one wavelength. What will be the resulting uncertainty in the electron's velocity?
NAME
Determine X in the following reaction:
necessary).
a.
neutron
e.
tritium
21
Ne + ,AX
+ l22 49 +~ d n
(use the table below if
/.,
10. An astronaut at rest on Earth has a heartbeat rate of 60 beatslmin. When the astronaut is traveling
in a spaceship at 0.80 c, what will this rate be as measured by an observer at rest on Earth?
LEc
c.
d.
e.
60 beatslrnin
77 beatslmin
85 beatslmin
11. Determine the amount of energy released in the fusion reaction:
:H + :H
+ :He + y
12. A simple circuit consists of a resistor R, an inductor L, a battery and a switch that is initially open
but then thrown closed. Immediately after the switch is thrown closed, the current in the circuit is
a. EIR.
c. need more information
NAME
13. An electron moves in a circular path perpendicular to a constant magnetic field. If the angular
momentum of the electron about the center of the circle is 4 . 0 0 ~ JSSand the radius of its path
is 10 cm, determine the magnitude of the magnetic field. ( Hint:the angular momentum of the
electron is L = mvr) Please show your work in solving this problem.
NAME
14. What is the speed of a particle if its kinetic energy equals 80% of its rest energy? Please show
your work in solving this problem.
NAME
15. An inductor and a resistor are connected in series. When connected to a 60 Hz, 100 V source, the
voltage drop across the resistor is found to be 30 V and the power delivered to the circuit is 9 W.
What is the value of the resistor? Please show your work in solving this problem.