Section 21.1
Creating and Measuring Electric Fields
Practice Test
1.
The electric field at the location of
q'
is represented by which of the following equations?
a.
E
=
W
/
q
'
b.
E
=
F
/
q'
c.
E
=
q
'
/
F
q
'
d.
E
=
q
/Δ
V
Hint
2.
An electric field is to be measured using a positive test charge of 3.0×10
-5
C. This test charge experiences a force of 0.50 N acting at an angle of 15°. What is the magnitude of the electric field at the location of the test charge?
a.
1.7×10
3
N/C
b.
0.49 N/C
c.
6.0×10
-5
N/C
d.
1.7×10
4
N/C
Hint
3.
An electric field is about 150 N/C downward. What is the direction of the force on a positively-charged particle?
a.
stationary
b.
changes rapidly
c.
downward
d.
upward
Hint
4.
A negative charge of 1.5×10
-7
C experiences a force of 0.030 N to the right in an electric field. What is the magnitude and direction of the field?
a.
2.0×10
5
N/C directed to the right
b.
2.0×10
5
N/C directed to the left
c.
4.5×10
-7
N/C directed to the right
d.
4.5x10
-9
N/C directed to the left
Hint
5.
The __________ is a vector quantity that relates the force on a test charge to the size of the charge.
a.
electric field
b.
capacitor
c.
potential
d.
equipotential
Hint
6.
According to Coulomb's law, the force on a test charge is __________ the test charge.
a.
proportional to
b.
greater than
c.
equal to
d.
less than
Hint
7.
A positive test charge of 9.0 × 10
-5
" to "9.0×10
-5
C is in an electric field that exerts a force of 3.7×10
-5
N on it. What is the magnitude of the electric field at the location of the test charge?
a.
0.41 N/C
b.
2.4 N/C
c.
4.1 N/C
d.
0.24 N/C
Hint
8.
Lines drawn to represent an electric field extend __________ a positive charge and __________ a negative charge.
a.
toward, away from
b.
away from, toward
c.
away from, away from
d.
toward, toward
Hint
