UNIVERSITY OF CALIFORNIA, BERKELEY
Physics Department
7b, Liphardt
Spring Term 2006
Final Exam
Name __________________________
Disc. Section ____________________
SID ____________________________
#1______ (20)
#2______ (20)
#3______ (20)
#4______ (20)
#5______ (20)
Total______
The relative weight of each problem is indicated next to the problem number.
Most credit will be given for algebraic work. Please do not insert numerical values until you have a final
algebraic answer inside a box. If you don’t know a particular constant, use a symbol to get partial credit. It is
almost impossible to award partial credit if you insert numbers too early. If you get stuck on one problem, go on
to the next and come back to the difficulties later in the exam period. Do not leave early until you have
completed everything. Do not quit! Never, never, never quit!!
As usual, before you start to manipulate equations and numbers you should
think for a moment
and make sure
that you have a general sense of the important features of a problem. Also, once you have computed something,
check to see if your answer has the right units, and if it is in the right ballpark. For example, if your answer to
any problem is something like
π
x 10
P
418
P
Kelvin/meters, you should check your work.
!!!!!!!!!!!!GOOD LUCK!!!!!!!!!!!
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Problem 1 [20].
A capacitor C = 3
μ
F is charged with Q = 4x10
P
4
P
C and is connected in series with a wire of
length
l
= 2 m. The wire has a circular crosssection of radius
r
= 1 mm, a resistivity of 4x10
P
8
P
Ω
m, a mass of
10
P
4
P
kg and a specific heat of 500 J/kgC
˚
. At
t
= 0, the capacitor begins to discharge through the resistor.
k
B
B
B
=
1.38*10
P
23
P
J/K.
(
a
) When does the voltage on the capacitor drop to 23 V?
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 Packard
 Physics, Electron, Electric charge, University of California, Boltzmann, BERKELEY Physics Department

Click to edit the document details