PSI AP Physics 2
Electric Current and Circuits
Multiple-Choice
Circuits
1. A heating spiral of resistance R converts electrical energy into thermal energy that is
transferred to the liquid in which the spiral is immersed. If the voltage across the spiral is
V, the thermal energy transferred to the liquid in time t is:
(A) Vrt
(B) V2Rt
(C) VR2t
(D)V2t/R
2. The product 3 amperes x 3 volts x 3 seconds is equal to
(A) 27 C
(B) 27 N
(C) 27 J
(D) 27 W
3. A certain coffeepot draws 2.0 A of current when it is operated on 110 V household lines.
If electrical energy costs 10 cents per kilowatt-hour, how much does it cost to operate
the coffeepot for 5 hours?
(A) 2.4 cents
(B) 4.8 cents
(C) 8.0 cents
(D) 11 cents
Conductors
4. A 60-W light bulb operating on a 120-volt household circuit has a resistance closest to
(A) 60 
(B) 120 
(C) 240 
(D) 180 
5. The circuit shown above left is made up of a variable resistor and a battery with
negligible internal resistance. A graph of the power P dissipated in the resistor as a
function of the current I supplied by the battery is given above right. What is the emf of
the battery?
(A) 0.125 V
(B) 5 V
(C) 8 V
(D) 40 V
Resistivity and Resistance
6. The length and radius of an aluminum wire is quadrupled. By which factor does the
resistance change?
(A) 2
(B) 1/2
(C) 1/4
(D) 1
7. A copper wire has a length L and cross-sectional area A. What happens to the resistivity
of the wire if the length is doubled and cross-sectional area halved?
(A) Four times as large (B) Stays the same (C) Half as large
(D) Quarter as large
8. The four resistors shown below have the lengths and cross-sectional areas indicated
and are made of material with the same resistivity. Which has the smallest resistance?
(A) A
(B) B
(C) C
(D) D
9. A single resistor is connected across the terminals of a battery. Which of the following
will leave the power output unaffected? Choose two answers.
(A) Reducing both the resistance and the voltage by a factor of 4.
(B) Reducing the resistance by a factor of 4 and the voltage by a factor of 2.
(C) Doubling both the resistance and the voltage.
(D) Doubling the voltage and increasing the resistance by a factor of 4.
Circuit Diagrams
10.
Which circuit has greater resistance between the terminals?
(A) A
(B) B
(C) C
(D) D
11.
Which circuits have the same resistance between the terminals?
(A) A and B
(B) B and C
(C) C and D
(D) A and D
12.
The equivalent resistance between the junction points of the above circuit shown on the
diagram is:
(A) 2 Ω
(B) 6 Ω
(C) 9 Ω
(D) 18 Ω
13. A battery and three identical lightbulbs are placed in various configurations. In which set
up will the bulbs be the brightness?
(A)
(B)
(C)
(D)
Questions 14-15
14.
In the circuit shown above, what is the value of the net resistance?
(A) 0.75 Ω
(B) 4.5 Ω
(C) 6 Ω
(D) 13 Ω
15. What is the current in 4 - Ω resistor?
(A) 2A
(B) 3A
(C) 9A
(D) 12A
16. What is the voltage between points L and M?
(A) 2 V
(B) 4 V
(C) 8 V
(D) 12 V
17. A lamp L1, a voltmeter V, an ammeter A, and a battery with zero internal resistance are
connected as shown above. Connecting another lamp L2 in series with the first lamp as
shown by the dashed lines would
(A) Increase the ammeter reading
(C) Decrease the ammeter reading
(B) Increase the voltmeter reading
(D) Decrease the voltmeter reading
18. In the circuit two identical resistors R are connected in series with 8- resistor and 12- V
battery. What is the value of R if the current in the circuit I = 1 A?
(A) 2 
(B) 4 
(C) 8 
(D) 12 
19. In the diagrams above, resistors R1 and R2 are shown in two different connections to the
same source of emf  that has no internal resistance. How does the power dissipated by
the resistors in these two cases compare?
(A) It is greater for the series connection.
(B) It is greater for the parallel connection.
(C) It is the same for both connections.
(D) One must know the values of R1 and R2 to know which is greater.
Questions 20-21 refer to the following diagram that shows part of a closed electrical circuit.
20. The electrical resistance of the part of the circuit shown between point X and point Y is
(A) 1.4 
(B) 2.5 
(C) 6.2 
(D) 10 
21. When there is a steady current in the circuit, the amount of charge passing a point per
unit of time is:
(A) the same everywhere in the circuit
(B) greater at point X than at point Y
(C) greater in the 2  resistor than in the 5  resistor
(D) the same in the 2  resistor as in the 5  resistor
Questions 22-24
Five identical light bulbs are connected to a 120 V power supply. Each light bulb has a
resistance of 15 Ω. The switch is closed.
22. What is the net resistance of the circuit?
(A) 3 Ω
(B) 30.1 Ω
(C) 40 Ω
(D) 75 Ω
23. What is the current in the light bulb L1?
(A) 1.6 A
(B) 3 A
(C) 8 A
(D) 40 A
24. Which light bulb or bulbs could burn out without causing any others to go out?
(A) Only L1
(B) Only L2
(C) Only L4
(D) Only L5
25. In reference to the circuit above, which of the follow statements are true? Choose two
answers. Choose two answers.
(A) The current in R1 must be the same as the current in R2.
(B) The current in R3 must be the same as the current in the battery.
(C) The voltage across R1 must be the same as the voltage across R2.
(D) The voltage across R3 must be the same as the voltage across the battery.
26. The diagrams above show four light bulbs of the same type. Two are in series and two
are in parallel. Which of the following statements are true? Choose two answers.
(A) The light bulbs in the series circuit are brightest since they get the total current.
(B) The light bulbs in the parallel circuit draw more power than in the series circuit.
(C) The series circuit has more total resistance than the parallel circuit.
(D) The parallel circuit has the less total current than the series circuit.
27. The following diagrams show resistors in four different circuits. Which two have the
same total resistance? Choose two answers.
(A)
(B)
(C)
(D)
Measurement
28. Which measuring device can measure resistance?
(A) Voltmeter
(B) Ammeter
(C) Multimeter
(D) None of the above
29. In order to measure the current and voltage through a circuit how must an ammeter and
voltmeter be connected to a circuit?
Ammeter
Voltmeter
(A) In parallel
(B) In parallel
(C) In series
(D) In series
in series
in parallel
in series
in parallel
EMF and Terminal Voltage
30. An electric current of 1 A flows through a circuit. The part of the circuit contains a 12 V
battery with an internal resistance of 2 Ω. What is the voltmeter reading?
(A) 4 V
(B) 8 V
(C) 10 V
(D n ) 12 V
31. An electric current of 2 A flows through a circuit. The part of the circuit contains a 6 V
battery with an internal resistance of 0.5 Ω. What is the voltmeter reading?
(A) 4 V
(B) 5 V
(C) 6 V
(D) 7 V
Question 32 and 33
A circuit is set up with a variable resistance. A graph is made with the voltage due to the current.
32. What part of the graph can be used to find the terminal voltage?
(A) the y intercept
(B) the x intercept
(C) the slope
(D) the dependent variable
33. What part of the graph can be used to find the resistance in the battery?
(A) the y intercept
(B) the x intercept
(C) the slope
(D) the negative of the slope
Questions 34 to 36
A circuit, shown above, has three resistors R1 = 60Ω, R2 = 30Ω, and R3 = 20Ω, and a 120V
battery with an internal resistance r = 4Ω. Use this circuit to answer questions 34 - 36.
34. What is the relationship between the three labeled currents?
(A) I1 =I2 < I < I3
(B) I1 + I2 + I3 = I
(C) I2 > I1 > I3 > I
(D) I1 + I2 = I3 = I
35. If V1 represents the potential difference across the first resistor, V2 across the second
resistor, V3 across the third resistor and V the terminal voltage in the battery. What is
the relationship between the V1, V2, V3, and V?
(A) V1 = V2 = V – V3
(B) V1 + V2 + V3 = V
(C) V1 = V2 = V3 < V
(D) V > V3 > V2 > V1
36. What is the ratio of current I1 in resistor R1 to the current in I2 in resistor R2?
𝐼
1
(A) 𝐼1 = 3
2
𝐼
1
(B) 𝐼1 = 2
2
𝐼
2
(C) 𝐼1 = 3
2
𝐼
2
(D) 𝐼1 = 1
2
37. A battery has an emf of ℰ and an internal resistance of r. What resistance R, when
connected across the terminals of the battery will make the terminal voltage to be ½𝓔?
(A) ½ r
(B) 2r
(C)
r
(D) 4r
38. An ammeter with an internal resistance of 3.6× 10−3 Ω is designed to measure the
maximum current of 0.2 A (full-scale-deflection). It was predicted that the maximum
current in the circuit is 2 A. What must the shunt resistance be and how it has to be
connected to the ammeter in order to measure the current in the given circuit?
(A) 3.6× 10−3 Ω in parallel
(B) 3.6× 10−3 in series
(C) 4× 10−4 Ω in parallel
(D) 4× 10−4 Ω in series
39. A voltmeter with an internal resistance of 20 Ω is design to measure the maximum
voltage of 2 V (full-scale-deflection). It was predicted that the maximum voltage in the
circuit is 120 V. What must the shunt resistance be and how it has to be connected to
the voltmeter in order to measure the voltage in the given circuit?
(A) 11,800 Ω in series
(B) 11,800 Ω in parallel
(C) 1,180 Ω in series
(D) 1,180 Ω in parallel
Kirchhoff’s Rules
Questions 40-42 relate to the following circuit diagram which shows a battery with an internal
resistance of 2.0 ohms connected to an 8-ohm and a 10-ohm resistor in series. The current in
the 10-ohm resistor is 0.2 amperes.
40. What is the emf of the battery?
(A) 0.4 V
(B) 3.6 V
(C) 4 V
(D) 12 V
41. What is the potential difference across the terminals A and B of the battery?
(A) 1.2 V
(B) 2.4 V
(C) 3.6 V
(D) 12.2 V
42. What power is dissipated by the 2-ohm internal resistance of the battery?
(A) 0.08 W
(B) 0.8 W
(C) 1.2 W
(D) 6.5 W
Capacitors
Questions 43-44 relate to the five incomplete circuits below composed of resistors R, all of
equal resistance, and capacitors C, all of equal capacitance. A battery that can be used to
complete any of the circuits is available.
43. Into which circuit should the battery be connected to obtain the greatest steady power
dissipation?
(A) A
(B) B
(C) C
(D) E
44. Which circuit will retain stored energy if the battery is connected to it and then
disconnected?
(A) B
(B) C
(C) D
(D) E
45. Two capacitors are connected in parallel as shown above. A voltage V is applied to the
pair. What is the ratio of charge stored on C1 to the charge stored on C2, when C1 = 3C2?
(A) 1/3
(B) 2/3
(C) 3/1
(D) 3/2
Questions 45-46 refer to the circuit shown below.
46. The equivalent capacitance for this network is:
(A) 1.5 F
(B) 2 F
(C) 4 F
(D) 10 F
47. The charge stored in the circuit is:
(A) 12C
(B) 18 C
(C) 24 C
(D) 48 C
Questions 48-50
Three capacitors with an equal capacitance C are connected to a battery V.
48. What is the net capacitance of the circuit?
(A) 3C
(B) 2C
(C) 3/2 C
(D) 2/3 C
49. What is the net charge stored in the circuit?
(A) CV
(B) 3CV/2
(C) 2CV/3
(D) CV/3
50. What is the potential difference between the points X and Y?
(A) 1/3 V
(B) 1/2 V
(C) 3/2 V
(D) 2/3 V
RC Circuits
The following diagram is for questions 50 to 51.
51. What is the current in the circuit before the switch is closed?
(A) 𝐼 =
(B) 𝐼 =
𝑉
𝑅1
𝑉
𝑅2
(C) 𝐼 = 𝑅
𝑉
1 +𝑅2
𝑉
−𝑅
2
1
(D) 𝐼 = 𝑅
52. After the switch is closed for a long time, what is the current in the circuit?
𝑉
(A) 𝐼 = 𝑅
1
(B) 𝐼 =
(C) 𝐼 =
(D) 𝐼 =
𝑉
𝑅2
𝑉
𝑅1 +𝑅2
𝑉
𝑅2 −𝑅1
53. The circuit in the diagram above contains three identical light bulbs connected as shown.
Initially, a switch connected to light bulb I is closed. Which of the following is correct
about brightness of light bulb II and III is correct when the switch is open?
Bulb II
Bulb III
(A) Gets brighter
Gets dimmer
(B) Gets dimmer
Gets brighter
(C) Gets brighter
Gets brighter
(D) Gets dimmer
Gets dimmer
54. Which of the following is true about the current through resistor R and charge in the
capacitor, immediately after the switch is closed?
Current I
Charge Q
(A) Zero
Maximum
(B) Maximum
Zero
(C) Zero
Zero
(D) Maximum
Maximum
55. Which of the following is true about the current through resistor R and charge in the
capacitor, when the switch is closed for a long time?
Current I
Charge Q
(A) Zero
Maximum
(B) Maximum
Zero
(C) Zero
Zero
(D) Maximum
Maximum
(E) Stays unchanged Stays unchanged
Use the circuit shown below to solve questions 56 to 59.
56. Rank the brightness of the lightbulb when the switch is open.
(A) 𝐿1 > 𝐿4 > 𝐿2 = 𝐿3
(B) 𝐿1 > 𝐿4 = 𝐿3 > 𝐿2
(C) 𝐿1 = 𝐿4 > 𝐿2 > 𝐿3
(D) 𝐿1 > 𝐿2 = 𝐿3 > 𝐿4
57. Rank the brightness of the lightbulb when the switch is first closed.
(A) 𝐿1 > 𝐿4 > 𝐿2 = 𝐿3
(B) 𝐿1 > 𝐿4 = 𝐿3 > 𝐿2
(C) 𝐿1 = 𝐿4 > 𝐿2 > 𝐿3
(D) 𝐿1 > 𝐿2 = 𝐿3 > 𝐿4
58. Rank the brightness of the lightbulb when the switch is closed for a long time.
(A) 𝐿1 > 𝐿4 > 𝐿2 = 𝐿3
(B) 𝐿1 > 𝐿4 = 𝐿3 > 𝐿2
(C) 𝐿1 = 𝐿4 > 𝐿2 > 𝐿3
(D) 𝐿1 > 𝐿2 = 𝐿3 > 𝐿4
Answers
1. C
2. D
3. C
4. D
5. C
6. C
7. C
8. B
9. B
10. B, D
11. B
12. D
13. C
14. B
15. C
16. A
17. B
18. B
19. A
20. B
21. B
22. D
23. C
24. B
25. D
26. A, D
27. B, C
28. A, D
29. C
30. D
31. C
32. D
33. A
34. C
35. D
36. A
37. B
38. C
39. C
40. C
41. C
42. C
43. A
44. A
45. D
46. C
47. D
48. D
49. C
50. D
51. C
52. A
53. A
54. B
55. A
56. A
57. B
58. A