### Quiz 5 – 2015.01.23

```The symbol ΦE represents the ____ of
an electric field.
Rank
1
2
3
Responses
4
5
6
0%
0%
1
2
0%
0%
3
4
0%
0%
5
6
For a fixed electric field E, the flux ΦE
increases with cross sectional area.
A. True
B. False
se
0%
Fa
l
Tr
ue
0%
The signs of point
charges q1 and q2
are:
–
q1
–,
q2
+
0%
q2
–,
q2
q1
+,
q2
+,
0%
–
0%
+
0%
q1
q1 +, q2 +
q1 +, q2 –
q1 –, q2 +
q1 –, q2 –
q1
A.
B.
C.
D.
The magnitude of
charge q1 is how
many times that of
q2 ?
Rank
Responses
1
2
3
4
5
6
0%
1
0%
2
0%
3
0%
4
0%
5
0%
6
The amount of flux through an area
depends on the orientation of the area
with respect to the electric field.
A. True
B. False
se
0%
Fa
l
Tr
ue
0%
What conditions on an area A will
maximize flux given a fixed electric field E.
0%
0%
at
ed
pl
ic
e
or
sm
It
i
m
E
d
an
A
co
us
tb
e
m
E
d
an
A
m
pe
r
us
tb
e
pe
pa
r
al
nd
...
le
l
0%
…
.
A. A and E must be
parallel
B. A and E must be
perpendicular
C. It is more
complicated….
Given a single point charge and
corresponding electric field, which
geometric object will maximize flux
when enclosing the charge:
0%
je
ct
an
ge
ob
Sp
he
bo
x
ar
rs
tr
ct
an
gu
l
0%
re
0%
x
0%
Bo
ot
he
e
So
m
Box
Rectangular box
Sphere
Some other strange
object
Re
A.
B.
C.
D.
Enclosing a point charge in a sphere of
radius R yields a flux ΦR. Taking the
same point charge and enclosing it in a
sphere of radius 2R yields a flux of Φ2R.
A. Φr < Φ2r
B. Φr > Φ2r
C. Φr = Φ2r
A closed surface encloses a net charge
of 2.50 μC. The net electric flux
through the surface is:
______ x 105 N m2/C
Rank
Responses
1
2
3
4
5
6
0%
0%
1
2
0%
3
0%
4
0%
5
0%
6
```