1. A 2.0-ohm resistor and a 4.0-ohm resistor are connected
in series with a 12-volt battery. If the current through
the 2.0-ohm resistor is 2.0 amperes, the current through
the 4.0-ohm resistor is
A) 1.0 A B) 2.0 A C) 3.0 A D) 4.0 A
2. Base your answer to the following question on The
diagram below represents a circuit consisting of two
resistors connected to a source of potential difference.
What is the current through the 20.-ohm resistor?
A) 0.25 A
C) 12 A
B) 6.0 A
D) 4.0 A
3. 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
6. A 3-ohm resistor and a 6-ohm resistor are connected in
parallel across a 9-volt battery. Which statement best
compares the potential difference across each resistor?
A) The potential difference across the 6-ohm
resistor is the same as the potential difference
across the 3-ohm resistor.
B) The potential difference across the 6-ohm resistor is
twice as great as the potential difference across the
3-ohm resistor.
C) The potential difference across the 6-ohm resistor is
half as great as the potential difference across the
3-ohm resistor.
D) The potential difference across the 6-ohm resistor is
four times as great as the potential difference across
the 3-ohm resistor.
7. Which circuit has the smallest equivalent resistance?
A)
B)
B) twice as great
D) four times as great
4. Base your answer to the following question on The
circuit diagram below represents four resistors connected
to a 12-volt source.
C)
What is the total current in the circuit?
A) 0.50 A
C) 8.6 A
B) 2.0 A
D) 24 A
5. A 3.0-ohm resistor arid a 6.0-ohm resistor are connected
in series in an operating electric circuit. If the current
through the 3.0-ohm resistor is 4.0 amperes, what is the
potential difference across the 6.0-ohm resistor?
A) 8.0 V B) 2.0 V C) 12 V
D) 24 V
D)
8. Which combination of resistors has the smallest
equivalent resistance?
A)
B)
C)
D)
9. 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)
10. 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)
less than 4 between 4 and 8 between 10 and 18 18 11. A circuit consists of a 10.0-ohm resistor, a 15.0-ohm
resistor, and a 20.0-ohm resistor connected in parallel
across a 9.00-volt battery. What is the equivalent
resistance of this circuit?
A) 0.200 C) 4.62 B) 1.95 D) 45.0 12. 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)
13. In the electric circuit diagram below, possible locations
of an ammeter and a voltmeter are indicated by circles
1, 2, 3, and 4
Where should an ammeter be located to correctly
measure the total current and where should a voltmeter
be located to correctly measure the total voltage?
A)
B)
C)
D)
ammeter at 1 and voltmeter at 4
ammeter at 2 and voltmeter at 3
ammeter at 3 and voltmeter at 4
ammeter at 1 and voltmeter at 2
Base your answers to questions 14 and 15 on the information below.
A 15-ohm resistor and a 20.-ohm resistor are connected in parallel with a 9.0-volt battery. A single
ammeter is connected to measure the total current of the circuit.
14. In the space below, draw a diagram of this circuit using symbols from the Reference Tables for Physical
Setting/Physics. [Assume the availability of any number of wires of negligible resistance.]
15. Calculate the equivalent resistance of the circuit. [Show all work, including the equation and substitution
with units.]
Base your answers to questions 16 and 17 on the information and diagram below.
A circuit contains a 12.0-volt battery, an ammeter, a variable resistor, and connecting wires of negligible
resistance, as shown below.
The variable resistor is a nichrome wire, maintained at 20.°C. The length of the nichrome wire may be
varied from 10.0 centimeters to 90.0 centimeters. The ammeter reads 2.00 amperes when the length of the
wire is 10.0 centimeters.
16. Determine the resistance of the 10.0-centimeter length of nichrome wire.
_______________________ 17. Calculate the cross-sectional area of the nichrome wire. [Show all work, including the equation and
substitution with units.]
18. The heating element in an automobile window has a
resistance of 1.2 ohms when operated at 12 volts.
Calculate the power dissipated in the heating element.
[Show all work, including the equation and substitution
with units.]
19. A simple circuit consists of a 100.-ohm resistor
connected to a battery. A 25-ohm resistor is to be
connected in the circuit. Determine the smallest
equivalent resistance possible when both resistors are
connected to the battery.
21. A 6-ohm resistor and a 4-ohm resistor are connected in
series with a 6-volt battery in an operating electric
circuit. A voltmeter is connected to measure the
potential difference across the 6-ohm resistor. In the space below, draw a diagram of this circuit
including the battery, resistors, and voltmeter using
symbols from the Reference Tables for Physical
settings/Physics. Label each resistor with its value.
[Assume the availability of any number of wires of
negligible resistance.]
22. In the space below, draw a diagram of an operating
circuit that includes:
_______________________ • a battery as a source of potential difference
• two resistors in parallel with each other
20. Calculate the resistance of a 900.-watt toaster operating
• an ammeter that reads the total current in the circuit
at 120 volts. [Show all work, including the equation
and substitution with units.]
Base your answers to questions 23 through 25 on the information below.
A 5.0-ohm resistor, a 10.0-ohm resistor, and a 15.0-ohm resistor are connected in
parallel with a battery. The current through the 5.0-ohm resistor is 2.4 amperes.
23. Using the circuit symbols found in the Reference Tables for Physical Setting/Physics, draw a diagram of
this electric circuit.
24. Calculate the amount of electrical energy expended in the 5.0-ohm resistor in 2.0 minutes. [Show all work,
including the equation and substitution with units.]
25. A 20.0-ohm resistor is added to the circuit in parallel with the other resistors. Describe the effect the
addition of this resistor has on the amount of electrical energy expended in the 5.0-ohm resistor in 2.0
minutes.
26. 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.]
Base your answers to questions 30 and 31 on the
information and diagram below.
A 10.0-meter length of copper wire is at 20ºC.
The radius of the wire is 1.0 × 10-3 meter.
Base your answers to questions 27 through 29 on the
information and diagram below.
A 15-ohm resistor R1, and a 30-ohm resistor, R2,
are to be connected in parallel between points A and B in a circuit containing a 90-volt battery.
30. Determine the cross-sectional area of the wire.
31. Calculate the resistance of the wire. [Show all work,
including the equation and substitution with units.]
27. Complete the diagram above, to show the two resistors
connected in parallel between points A and B.
28. Determine the potential difference across resistor R 1.
29. Calculate the current in resistor R 1. [Show all work,
including the equation and substitution with units.]
Answer Key
Circuits (AP)
1.
B
2.
D
3.
C
4.
A
5.
D
6.
A
7.
C
8.
C
9.
B
10.
A
11.
C
12.
A
13.
A
21.
22.
23.
24.
25.
14.
The energy expended
in the 5.0-ohm
resistor remains the
same.
26.
15.
Req = 8.6 16.
6.00 17.
18.
19.
20.
20. 27.
28.
90 V
29.
6.0 A
30.
3.1 × 10 –6 m 2
31.
5.5 × 10 -2