Electrostatics
1. A 150-watt lightbulb is brighter than a 60.-watt lightbulb
when both are operating at a potential difference of 110
volts. Compared to the resistance of and the current
drawn by the 150-watt lightbulb, the 60.-watt lightbulb
has
A)
B)
C)
D)
less resistance and draws more current
less resistance and draws less current
more resistance and draws more current
more resistance and draws less current
2. A 3.6-volt battery is used to operate a cell phone for 5.0
minutes. If the cell phone dissipates 0.064 watt of power
during its operation, the current that passes through the
phone is
A) 0.018 A
C) 19 A
6. Which circuit segment has an equivalent resistance of 6
ohms?
A)
B)
C)
D)
7. The diagram below shows two resistors connected in
series to a 20.-volt battery.
B) 5.3 A
D) 56 A
3. In the circuit diagram below, two 4.0-ohm resistors are
connected to a 16-volt battery as shown.
If the current through the 5.0-ohm resistor is 1.0 ampere,
the current through the 15.0-ohm resistor is
A) 1.0 A
C) 3.0 A
B) 0.33 A
D) 1.3 A
8. The diagram below represents a simple electric circuit.
The rate at which electrical energy is expended in this
circuit is
A) 32 W B) 16 W C) 8.0 W D) 64 W
4. A 50-watt lightbulb and a 100-watt lightbulb are each
operated at 100 volts. Compared to the resistance of the
50-watt bulb, the resistance of the 100-watt bulb is
A) four times as great
C) twice as great
B) one-fourth as great
D) half as great
5. The diagram below shows a circuit with three resistors.
How much charge passes through the resistor in 2.0
seconds?
A) 6.0 C B) 2.0 C C) 8.0 C D) 4.0 C
What is the resistance of resistor R3?
A) 6.0 B) 2.0 C) 12 D) 4.0 Electrostatics
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Electrostatics
9. The diagram below shows three resistors, R1, R2, and R3,
connected to a 12-volt battery.
13. The circuit diagram below represents four resistors
connected to a 12-volt source.
What is the total current in the circuit?
If voltmeter V1 reads 3 volts and voltmeter V2 reads 4
volts, what is the potential drop across resistor R3?
A) 12 V
B) 5 V
C) 0 V
D) 4 V
10. Base your answer to the following question on the
diagram below.
A) 24 A
C) 8.6 A
B) 0.50 A
D) 2.0 A
14. Moving 4.0 coulombs of charge through a circuit
requires 48 joules of electric energy. What is the
potential difference across this circuit?
A) 190 V B) 48 V C) 12 V D) 4.0 V
15. In the circuit diagram below, what are the correct
readings of voltmeters V1 and V2?
The reading of voltmeter V will be
A) 5 volts
C) 10 volts
B) 0.2 volt
D) 20 volts
11. The diagram below represents a circuit consisting of
two resistors connected to a source of potential
difference.
A)
B)
C)
D)
V1 reads 4.0 V and V2 reads 2.0 V
V1 reads 3.0 V and V2 reads 3.0 V
V1 reads 2.0 V and V2 reads 4.0 V
V1 reads 6.0 V and V2 reads 6.0 V
16. In the diagram below, lamps L1 and L2 are connected to
a constant voltage power supply.
What is the current through the 20.-ohm resistor?
If lamp L1 burns out, the brightness of L2 will
A) 0.25 A
C) 12 A
A) increase
C) remain the same
B) 6.0 A
D) 4.0 A
B) decrease
12. Circuit A has four 3.0-ohm resistors connected in series
with a 24-volt battery, and circuit B has two 3.0-ohm
resistors connected in series with a 24-volt battery.
Compared to the total potential drop across circuit A,
the total potential drop across circuit B is
A) one-half as great
C) the same
B) twice as great
D) four times as great
Electrostatics
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Electrostatics
17. Which circuit has the smallest equivalent resistance?
A)
20. The diagram below represents currents in a segment of
an electric circuit.
B)
What is the reading of ammeter A?
A) 1 A
C)
B) 3 A
C) 4 A
D) 2 A
D)
18. Three identical lamps are connected in parallel with
each other. If the resistance of each lamp is X ohms,
what is the equivalent resistance of this parallel
combination?
A)
B)
C)
D)
19. Three resistors, 4 ohms, 6 ohms, and 8 ohms, are
connected in parallel in an electric circuit. The
equivalent resistance of the circuit is
A)
B)
C)
D)
18 between 10 and 18 between 4 and 8 less than 4 Electrostatics
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Electrostatics
21. In which circuit would current flow through resistor R 1, but not through resistor R 2 while switch S is
open?
A)
B)
C)
D)
22. In the circuit diagram shown below, ammeter A1 reads
10. amperes.
25. In the circuit diagram shown below, what is the current
through the 4.0-ohm resistor?
A) 1.0 ampere
C) 3.0 amperes
What is the reading of ammeter A2?
B) 0.33 ampere
D) 48 amperes
26. The diagram below shows currents in a segment of an
electric circuit.
A) 6.0 A B) 10. A C) 4.0 A D) 20. A
Base your answers to questions 23 and 24 on the
diagram below, which shows two resistors and three
ammeters connected to a voltage source.
23. What is the current reading of ammeter A1 ?
A) 10.0 A
C) 3.0 A
What is the reading of ammeter A?
B) 6.0 A
D) 4.0 A
A) 1 A
24. What is the potential difference across the source?
A) 120 V B) 60. V C) 220 V D) 440 V
B) 5 A
C) 9 A
D) 15 A
27. Conductivity in metallic solids is due to the presence of
free
A) electrons
C) neutrons
Electrostatics
B) nuclei
D) protons
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Electrostatics
28. Compared to insulators, metals are better conductors of
electricity because metals contain more free
A) electrons
C) negative ions
B) protons
D) positive ions
29. An MP3 player draws a current of 0.120 ampere from a
3.00-volt battery. What is the total charge that passes
through the player in 900. seconds?
A) 324 C
C) 5.40 C
A)
B) 108 C
D) 1.80 C
30. The current in a wire is 4.0 amperes. The time required
for electrons to pass a certain point in the
wire is
A) 1.0 s
33. A copper wire is part of a complete circuit through
which current flows. Which graph best represents the
relationship between the wire's length and its
resistance?
B)
B) 0.25 s C) 0.50 s D) 4.0 s
31. What is the current in a wire if 3.4 × 1019 electrons pass
by a point in this wire every 60. seconds?
1.8 × 10 –18 A
A)
C) 9.1 × 10 –2 A
C)
3.1 × 10 –11 A
B)
D) 11 A
32. A manufacturer recommends that the longer the
extension cord used with an electric drill, the thicker
(heavier gauge) the extension cord should be. This
recommendation is made because the resistance of a
wire varies
A) directly with length and inversely with
cross-sectional area
B) directly with both length and cross-sectional area
C) inversely with length and directly with
cross-sectional area
D) inversely with both length and cross-sectional area
D)
34. If the length of a copper wire is reduced by half, then
the resistance of the wire will be
A) quartered
C) doubled
B) quadrupled
D) halved
35. Which change decreases the resistance of a piece of
copper wire?
A)
B)
C)
D)
decreasing the wire’s temperature
increasing the wire’s length
increasing the wire’s resistivity
decreasing the wire’s diameter
36. A circuit consists of a resistor and a battery. Increasing
the voltage of the battery while keeping the temperature
of the circuit constant would result in an increase in
A)
B)
C)
D)
Electrostatics
neither current nor resistance
current, only
resistance, only
both current and resistance
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Electrostatics
37. A complete circuit is left on for several minutes,
causing the connecting copper wire to become hot. As
the temperature of the wire increases, the electrical
resistance of the wire
A) decreases
C) remains the same
B) increases
A) halved
C) quartered
38. An incandescent light bulb is supplied with a constant
potential difference of 120 volts. As the filament of the
bulb heats up, its resistance
A)
B)
C)
D)
increases and the current through it decreases
decreases and the current through it decreases
decreases and the current through it increases
increases and the current through it increases
39. If the diameter of a wire were decreased, its electrical
resistance would
A) decrease
C) remain the same
45. An electric circuit consists of a variable resistor
connected to a source of constant potential difference.
If the resistance of the resistor is doubled, the current
through the resistor is
B) increase
B) doubled
D) quadrupled
46. In a simple electric circuit, a 24-ohm resistor is
connected across a 6.0-volt battery. What is the current
in the circuit?
A) 4.0 A
C) 1.0 A
B) 140 A
D) 0.25 A
47. What is the minimum equipment needed to determine
the power dissipated in a resistor of unknown value?
A)
B)
C)
D)
a voltmeter and an ammeter, only
an ammeter, only
a voltmeter, only
a voltmeter, an ammeter, and a stopwatch
40. The electrical resistance of a metallic conductor is
inversely proportional to its
A)
B)
C)
D)
temperature
cross-sectional area
resistivity
length
41. If a wire of cross-sectional area equal to A has a
resistance of R, then another wire of the same material
with a cross-sectional area equal to 2A will have a
resistance of
A) R
B) 2R
C) R/2
D) R/4
42. At 20°C, four conducting wires made of different
materials have the same length and the same diameter.
Which wire has the least resistance?
A) nichrome
C) gold
B) tungsten
D) aluminum
43. A 0.686-meter-long wire has a cross-sectional area of
8.23 ×10 –6 meter 2 and a resistance of 0.125 ohm at 20°
Celsius. This wire could be made of
A) aluminum
C) tungsten
B) copper
D) nichrome
44. Pieces of aluminum, copper, gold, and silver wire each
have the same length and the same cross-sectional area.
Which wire has the lowest resistance at 20°C?
A) silver
C) copper
B) aluminum
D) gold
Electrostatics
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Electrostatics
48. The resistance of a circuit remains constant. Which
graph best represents the relationship between the
current in the circuit and the potential difference
provided by the battery?
49. Which graph best represents the relationship between
the power expended by a resistor that obeys Ohm's Law
and the potential difference applied to the resistor?
A)
A)
B)
B)
C)
C)
D)
D)
50. A length of copper wire and a 1.00-meter-long silver
wire have the same cross-sectional area and resistance
at 20°C. Calculate the length of the copper wire. [Show
all work, including the equation and substitution with
units.]
Electrostatics
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Answer Key
Electricity practice test
1.
D
37.
B
2.
A
38.
A
3.
A
39.
B
4.
D
40.
B
5.
B
41.
C
6.
D
42.
C
7.
A
43.
D
8.
C
44.
A
9.
B
45.
A
10.
C
46.
D
11.
D
47.
A
12.
C
48.
C
13.
B
49.
D
14.
C
50.
15.
D
16.
C
17.
D
18.
B
19.
D
20.
D
21.
B
22.
A
23.
B
24.
A
25.
C
26.
C
27.
A
28.
A
29.
B
30.
A
31.
C
32.
A
33.
D
34.
D
35.
A
36.
B
Electrostatics
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