Chapter 21:
Electric Fields
Practice Test
1.
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 left
b.
4.5 X10
-9
N/C directed to the left
c.
4.5 × 10
-7
N/C directed to the right
d.
2.0 × 10
5
N/C directed to the right
Hint
2.
An electric field is about 150 N/C downward. What is the direction of the force on a positively-charged particle?
a.
downward
b.
changes rapidly
c.
upward
d.
stationary
Hint
3.
Touching a body to Earth to eliminate excess charge is called __________.
a.
capacitance
b.
resistance
c.
grounding
d.
static
Hint
4.
The electric field at the location of
q'
is represented by which of the following equations?
a.
E= F/
q'
b.
E= q/ΔV
c.
E= W/
q'
d.
E= q'/F
q'
Hint
5.
A 6.4-ΜF capacitor is first charged so that the electric potential difference is 5.0 V. How much additional charge is needed to increase the electric potential difference to 12.0 V?
a.
7.7 × 10
5
C
b.
4.5 × 10
5
C
c.
7.7 × 10
-5
C
d.
4.5 × 10
-5
C
Hint
6.
When the electric potential difference between two positions in an electric field is zero, the positions are __________.
a.
at equipotential
b.
close together
c.
in equilibrium
d.
polar
Hint
7.
Lines drawn to represent an electric field extend __________ a positive charge and __________ a negative charge.
a.
away from, away from
b.
toward, away from
c.
toward, toward
d.
away from, toward
Hint
8.
The electric field intensity between two large, charged, parallel metal plates is 6500 N/C. The plates are 12 cm apart. What is the electric potential difference between them?
a.
7.8 × 10
4
V
b.
7.8 × 10
2
V
c.
7.8 × 10
-2
V
d.
7.8 × 10
5
V
Hint
9.
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 degrees. What is the magnitude of the electric field at the location of the test charge?
a.
1.7 × 10
4
N/C
b.
6.0 × 10
-5
N/C
c.
1.7 × 10
3
N/C
d.
0.49 N/C
Hint
10.
What work is done when 3.5 C is moved through an electric potential difference of 4.5 V?
a.
7.8 × 10
-1
J
b.
negative 1.6 × 10
1
J
c.
1.6 × 10
1
J
d.
1.6 × 10
1
J/C
Hint
