Current Electricity
Practice Test
1.
If the resistance of the lightbulb in Figure 22-3 were changed to 6 Ω, what would tha ammeter read?
a.
8 A
b.
2 A
c.
6 A
d.
4 A
Hint
2.
In order to convert a quantity expressed in one unit into the same quantity in a different unit, use a(n) __________.
a.
algebraic quantity
b.
notation factor
c.
conversion factor
d.
calculation coefficient
Hint
3.
A bike rider approaches a hill at a speed of 3.5 m/s. The mass of the bike and rider together is 77 kg. What is the initial kinetic energy of the system?
a.
2.6×10
3
J
b.
3.1×10
3
J
c.
1.2×10
3
J
d.
4.7×10
2
J
Hint
4.
In Figure 22-3, if the battery voltage were changed to 9 V, what would the ammeter reading be?
a.
1 A
b.
4 A
c.
2 A
d.
3 A
Hint
5.
__________ describes the degree of exactness in a measurement.
a.
Accuracy
b.
Significance
c.
Precision
d.
Parallax
Hint
6.
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.
1.7×10
4
N/C
d.
6.0×10
-5
N/C
Hint
7.
A 75.0 W lightbulb is 25.0% efficient. How many joules of thermal energy does the lightbulb produce each minute?
a.
3380 J
b.
563 J
c.
1130 J
d.
4500 J
Hint
8.
The apparent shift in the position of an object when it is viewed from different angles is caused by __________.
a.
faulty instruments
b.
parallax
c.
inaccuracy
d.
imprecise measurement
Hint
9.
Combinations of SI base units are called __________.
a.
straight measurements
b.
dimensional analogs
c.
derived units
d.
base quantities
Hint
10.
Coulomb's law states that __________.
a.
the magnitude of the force between two charges is inversely proportional to the magnitude of the charges and proportional to the square of the distance between them
b.
the ratio of the potential difference to the current is constant
c.
the magnitude of the force between two charges is proportional to the magnitude of the charges and inversely proportional to the square of the distance between them
d.
the direction of the magnetic field in a wire is perpendicular to the flow of electric current in the wire
Hint
11.
The ratio of charge stored to electric potential difference is called the __________.
a.
capacitor
b.
resistance
c.
capacitance
d.
current
Hint
12.
If the positive charge of an atom's nucleus exactly balances the negative charge of the surrounding electrons, the atom is __________.
a.
electrified
b.
neutral
c.
positively-charged
d.
static
Hint
13.
In Figure 20-8, if the charge on the rod were positive, what effect, if any, would this have on the final result?
a.
It would have no effect.
b.
The left sphere would still be positive and the right sphere would still be negative, but there would be less total charge on each.
c.
The left sphere would still be positive and the right sphere would still be negative, but there would be more total charge on each.
d.
The left sphere would be negatively charged and the right sphere would be positively charged, with the same amount of charge as in the original picture c.
Hint
14.
A kilowatt-hour is equivalent to:
a.
3.6×10
6
J
b.
1.0×10
3
J/s
c.
3.6×10
6
J/s
d.
1.0×10
3
J
Hint
15.
In Figure 11-5, if the mass of an orange is about 0.6 kg, about how much more gravitational potential energy does the topmost orange have than the one in the juggler's left hand?
a.
60 J
b.
600 J
c.
6 J
d.
0.6 J
Hint
16.
In Figure 11-5, estimate the vertical velocity of an orange when it hits the juggler's left hand.
a.
4.5 m/s
b.
2 m/s
c.
0.45 m/s
d.
20 m/s
Hint
17.
In the set-up of Figure 21-9, if the electric force up on a drop equals the gravitational force down on the drop, the drop ___.
a.
could move upward at constant speed
b.
will accelerate down
c.
will accelerate up
d.
must be stationary
Hint
18.
What are the two kinds of electrical charges?
a.
destructive and constructive
b.
high and low
c.
static and dynamic
d.
positive and negative
Hint
19.
Objects that are lifted against the force of gravity have stored energy known as __________.
a.
resistance
b.
reference levels
c.
potential energy
d.
kinetic energy
Hint
20.
Lines drawn to represent an electric field extend __________ a positive charge and __________ a negative charge.
a.
toward, away from
b.
away from, away from
c.
toward, toward
d.
away from, toward
Hint
