Download .1 is positive, Q2 is negative, Q3

Last 4 Digits of Student ID#
First 2 Letters of Last Name
QI-4: Circle the correct answer:
Each
I.
problem
(3pts)
~
has ONE best answer.
Thinking
about
the
difference
true?
between
insulators
work «:3
A.
Since chgren't/ free to
insulato
B.
It
isn’t
- ‘
CXTCXE
move
on
an i
*2 pr
ulator,
it
W
W F
and
conductors,
which
of the
following
is
end» .
is
very difficult to ever get excess
charge
on
an
.X
p
'
e
to polarize the charge
in a conC? since
the
(free) electrons
will
always
move
to
neutralize any positive charge in the conducto . X
C.
Since charges
are
(relatively)
stationary
in
an i
ator,
they
are always
aligned
in the atoms
and
molecules of the insulator in such a way that there can never be an electric field within the insulatorx
a Conductors with excess charge on them must be insulated from ground or else all the charge would\,,,
flow oi; the conductor.
E.
2.
More
(3pts)
The
ne
figure
of the
above
shows three
is true.
electric
charges
labeled
Q1,
Q2,
Q3,
and
some electric
region surrounding the charges. What are the signs of the three charges?
.1 is positive, Q2 is negative, Q3
is
B.
positive.
Q1
is
negative,
Q2
is positive,
Q3
is negative.
C.
Q1
is
positive,
Q2
is
positive,
Q3
is negative.
111.0
g!
m
three charges are negative.
All
three
charges are
positive,
(3 pts) A hollow conducting spherical shell has radii of 0.80
and
1.20
excess
at
All
the
m,
charge
center.
as
of
The
shown
-500
in
nC.
surface
the
A
figure.
point
charge
The
charge
density
sphere
of +300
on
the
carries
nC
inner
is
an
present
spherical
surface is closest to
A) zero.
CF?“
B) +4.0
x 10-8 C/m2.
C
X
+6.0
10'8 C/ m2.
“3) 4.0 x 10-8 Cl m2.
min x 10-8 C/ m2.
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C/Mt
JR:
field
lines
in the
(3pts) Two charges are placed along the x-axis. A charge of 3. O mC sits at x=0.0cm and a charge
of 6. O mC
sits at x=9. Gem.
Where15 the electric field equal to zero? At x=
(A) 4 5 cm,
has.
(B) 3. 0 cm,
@WSZ
El 6. 0 cm
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(E) 5 £523
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SQYour
study buddy tells you that the electric field surrounding a single point charge is
.Explain whether you agree or disagree with this idea and w Wyhat woulyerter word
u
to
describe
this
field?
m‘QU—en:
{$“V‘fc gogroive
<—3
914:2;
6. (4 pts) The shaded positive charge
experiences a net force due to two other
charges, +Q and +4Q. The position of the
+Q charge is indicated on the diagram.
Draw
in the position of the +4Q charge so
~
that the shaded positive charge
experiences the force indicated on the
diagram.
iii =iEuei
7.
(4pts) A cone is resting on a tabletop as shown in the figure
with
\F
SCAN
its face horizontal. A uniform electric field of magnitude
4550 N/C points vertically upward. How much electric flux
passes through the sloping side surface area of the cone?
1'
dlr 51*”‘31
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Last 4
Digits of Student
8.
(12pts)
L.
The
Charge Q1s
rod 15 then
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ID #
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Letters of Last
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The center ofthe
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circle15 at the origin.
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Write an expression for the x-component of‘the electric field at the
b)
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What
the
c)
Hint:
angle
origin
with
respect
to
the
positive
x-axis
will
the
electric
field
at
.
have?
.,
Write an expression or the total magnitude of the electric field at the
"
origin.
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First/ind out who! is the radius of the semicircle.
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Last 4 Digits of Student ID#
First 2
Letters of Last Name
A
aw Consider a very long, round, solid nonconductive cylinder of radius R with a volume charge density
of p
=
a)
—Cr, centered
on the z-axis.
Where r is the distance
the z-axis,
and
C is a positive
constant.
What are the units for C?
Use Gauss‘s Law to find the electric
b)
rgk and
c)
r>R.
This cylinder is
I
field
everywhere
in space in
and
long enough that you can safely ignore fringe effects.
\/thielectric field?
a)
from
[637: 918?:
=> LC] =
,
around this charged
Don‘t
forget to
rod,
l
at
l
include the direction of
®
C
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