Potential difference and power
9.2What the syllabus asks of you
- define the potential difference across a component as the energy transferred per unit charge
- recall and use V = W / Q
- recall and use P = VI, P = I²R and P = V²/R
Read the notes first
Chapter 9: Potential difference and power
Drill this topic
Every question on Potential difference and power, untimed, marked as you go.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
61 questions
1May / June 2026 · Paper 11 · Q31Show mark scheme →
Athe energy transferred per unit charge
Bthe energy transferred per unit current
Cthe power transferred per unit charge
Dthe power transferred per unit current
Mark scheme
2May / June 2026 · Paper 11 · Q33Show mark scheme →
A
B
C
D
Mark scheme
3May / June 2026 · Paper 12 · Q30Show mark scheme →
Athe current in the resistor and the potential difference across the resistor
Bthe resistance of the resistor and the current in the resistor
Cthe total charge passing through the resistor and the potential difference across the resistor
Dthe total charge passing through the resistor and the resistance of the resistor
Mark scheme
4May / June 2026 · Paper 13 · Q31Show mark scheme →
A1, 2 or 3
B1 or 2 only
C1 only
D2 only
Mark scheme
5May / June 2026 · Paper 14 · Q32Show mark scheme →
AV = EQ
BV = E/Q
CV = PR
DV = √(PR)
Mark scheme
6Oct / Nov 2025 · Paper 11 · Q31Show mark scheme →
AP = V²I
BP = V²/I
CP = V²R
DP = V²/R
Mark scheme
7Oct / Nov 2025 · Paper 12 · Q32Show mark scheme →
A0.44P
B0.67P
C1.5P
D2.3P
Mark scheme
8Oct / Nov 2025 · Paper 13 · Q31Show mark scheme →
AP = V²I
BP = V²/I
CP = V²R
DP = V²/R
Mark scheme
9May / June 2025 · Paper 13 · Q37Show mark scheme →
A16 Ω
B36 Ω
C44 Ω
D64 Ω
Mark scheme
10May / June 2025 · Paper 14 · Q30Show mark scheme →
Aone coulomb per second
Bone joule per coulomb
Cone joule per second
Done joule second per coulomb squared
Mark scheme
11Oct / Nov 2024 · Paper 11 · Q33Show mark scheme →
A0.067 A
B0.20 A
C0.60 A
D0.83 A
Mark scheme
12Oct / Nov 2024 · Paper 13 · Q34Show mark scheme →
A\frac{1}{2}V
B2V
C3V
D4V
Mark scheme
13May / June 2024 · Paper 11 · Q32Show mark scheme →
Apower / W: 500, current / A: 0.5
Bpower / W: 500, current / A: 5.0
Cpower / W: 2500, current / A: 0.1
Dpower / W: 2500, current / A: 10
Mark scheme
14May / June 2024 · Paper 12 · Q29Show mark scheme →
Aenergy transferred per unit charge
Benergy transferred per unit current
Cenergy transferred per unit distance
Denergy transferred per unit time
Mark scheme
15May / June 2024 · Paper 12 · Q36Show mark scheme →
A
B
C
D
Mark scheme
16May / June 2024 · Paper 13 · Q30Show mark scheme →
Acurrent
Benergy transferred
Cpower dissipated
Dresistance
Mark scheme
17Feb / March 2024 · Paper 12 · Q34Show mark scheme →
A0.16 Ω
B0.64 Ω
C100 Ω
D400 Ω
Mark scheme
18Oct / Nov 2023 · Paper 12 · Q31Show mark scheme →
A2.4 A
B3.7 A
C4.5 A
D14 A
Mark scheme
19Oct / Nov 2023 · Paper 13 · Q31Show mark scheme →
Athe energy transferred per unit charge
Bthe energy transferred per unit current
Cthe power transferred per unit charge
Dthe power transferred per unit current
Mark scheme
20May / June 2023 · Paper 11 · Q31Show mark scheme →
Athe charge per unit time passing through the component
Bthe energy transferred per unit charge
Cthe force per unit charge
Dthe resistance per unit current
Mark scheme
21May / June 2023 · Paper 12 · Q31Show mark scheme →
Adoubling the value of E
Bdoubling the value of R
Chalving the value of E
Dhalving the value of R
Mark scheme
22Feb / March 2023 · Paper 12 · Q30Show mark scheme →
A1.0 pJ
B10 pJ
C1.0 nJ
D10 nJ
Mark scheme
23Feb / March 2023 · Paper 12 · Q31Show mark scheme →
Aenergy transferred per unit charge
Benergy transferred per unit current
Cenergy transferred per unit resistance
Denergy transferred per unit time
Mark scheme
24Oct / Nov 2022 · Paper 11 · Q32Show mark scheme →
A0.44 J
B29 J
C1.6 kJ
D11 kJ
Mark scheme
25Oct / Nov 2022 · Paper 12 · Q32Show mark scheme →
AP/4
BP/2
CP
D2P
Mark scheme
26May / June 2022 · Paper 11 · Q32Show mark scheme →
Athe electrical power supplied to the component
Bthe energy transferred to the component per unit charge
Cthe product of the current in the component and its resistance
Dthe voltage across the component
Mark scheme
27May / June 2022 · Paper 12 · Q32Show mark scheme →
A0.22
B0.75
C1.3
D4.5
Mark scheme
28May / June 2022 · Paper 13 · Q33Show mark scheme →
A$I = \dfrac{P}{V}$
B$Q = \dfrac{W}{V}$
C$R = \dfrac{P}{I^2}$
D$R = \dfrac{V}{P}$
Mark scheme
29Feb / March 2022 · Paper 12 · Q31Show mark scheme →
ALamp P emits four times as much power as lamp Q.
BLamp P emits twice as much power as lamp Q.
CLamp Q emits four times as much power as lamp P.
DLamp Q emits twice as much power as lamp P.
Mark scheme
30May / June 2021 · Paper 11 · Q33Show mark scheme →
A2700 J
B9000 J
C14 000 J
D18 000 J
Mark scheme
31May / June 2021 · Paper 12 · Q33Show mark scheme →
Apower / kW: 2.3, p.d. / V: 230
Bpower / kW: 2.3, p.d. / V: 235
Cpower / kW: 2.4, p.d. / V: 230
Dpower / kW: 2.4, p.d. / V: 235
Mark scheme
32Oct / Nov 2020 · Paper 11 · Q33Show mark scheme →
Apower per unit current
Bproduct of current and resistance
Cproduct of electric field strength and distance
Dwork done per unit charge
Mark scheme
33Oct / Nov 2020 · Paper 12 · Q34Show mark scheme →
A2.4 A
B3.7 A
C4.5 A
D14 A
Mark scheme
34Oct / Nov 2020 · Paper 13 · Q34Show mark scheme →
AIt is from electrical energy into other forms.
BIt is from other forms into electrical energy.
CIt only takes place inside a power supply.
DIt only takes place inside resistors.
Mark scheme
35May / June 2020 · Paper 12 · Q34Show mark scheme →
A0.40 A
B0.63 A
C1.6 A
D2.5 A
Mark scheme
36May / June 2020 · Paper 13 · Q4Show mark scheme →
Aammeter range 0–0.5 A, voltmeter range 0–20 V
Bammeter range 0–0.5 A, voltmeter range 0–100 V
Cammeter range 0–10 A, voltmeter range 0–20 V
Dammeter range 0–10 A, voltmeter range 0–100 V
Mark scheme
37Oct / Nov 2019 · Paper 12 · Q32Show mark scheme →
A0.48 W
B0.96 W
C1.9 W
D4.8 W
Mark scheme
38Oct / Nov 2019 · Paper 12 · Q33Show mark scheme →
Athe current in the resistor and the potential difference across the resistor
Bthe resistance of the resistor and the current in the resistor
Cthe total charge passing through the resistor and the potential difference across the resistor
Dthe total charge passing through the resistor and the resistance of the resistor
Mark scheme
39May / June 2019 · Paper 11 · Q33Show mark scheme →
AThe energy needed to move +1 C of charge from P to Q is 1 J.
BThe energy needed to move +1 C of charge from Q to P is 1 J.
CThe energy needed to move one electron from P to Q is 1 J.
DThe energy needed to move one electron from Q to P is 1 J.
Mark scheme
40May / June 2019 · Paper 13 · Q32Show mark scheme →
Aampere and ohm
Bcoulomb and joule
Ccoulomb and ohm
Dcoulomb and second
Mark scheme
41May / June 2019 · Paper 13 · Q35Show mark scheme →
A31 W
B49 W
C31 kW
D49 kW
Mark scheme
42Feb / March 2019 · Paper 12 · Q33Show mark scheme →
A2 : 3 : 4
B4 : 3 : 2
C6 : 4 : 3
D36 : 16 : 9
Mark scheme
43Oct / Nov 2018 · Paper 11 · Q34Show mark scheme →
Aone coulomb per second
Bone joule per coulomb
Cone joule per second
Done joule second per coulomb squared
Mark scheme
44Oct / Nov 2018 · Paper 12 · Q34Show mark scheme →
A16 Ω
B36 Ω
C44 Ω
D60 Ω
Mark scheme
45May / June 2018 · Paper 11 · Q31Show mark scheme →
A0.22
B0.75
C1.3
D4.5
Mark scheme
46May / June 2018 · Paper 12 · Q16Show mark scheme →
A0.95 hours
B12.4 hours
C18.6 hours
D27.9 hours
Mark scheme
47May / June 2018 · Paper 12 · Q32Show mark scheme →
Apower / kW: 2.3, p.d. / V: 230
Bpower / kW: 2.3, p.d. / V: 235
Cpower / kW: 2.4, p.d. / V: 230
Dpower / kW: 2.4, p.d. / V: 235
Mark scheme
48Feb / March 2018 · Paper 12 · Q33Show mark scheme →
AI = P/V
BQ = W/V
CR = P/I^2
DR = V/P
Mark scheme
49Oct / Nov 2017 · Paper 11 · Q34Show mark scheme →
A45 W
B90 W
C290 W
D360 W
Mark scheme
50Oct / Nov 2017 · Paper 12 · Q19Show mark scheme →
A2700 A
B$8.2 \times 10^4$ A
C$7.4 \times 10^6$ A
D$6.6 \times 10^8$ A
Mark scheme
51May / June 2017 · Paper 11 · Q33Show mark scheme →
Acurrent 1 A, resistance 4 Ω
Bcurrent 2 A, resistance 8 Ω
Ccurrent 4 A, resistance 1 Ω
Dcurrent 16 A, resistance 1 Ω
Mark scheme
52May / June 2017 · Paper 12 · Q33Show mark scheme →
A36 Ω
B580 Ω
C1.5 kΩ
D9.2 kΩ
Mark scheme
53May / June 2017 · Paper 13 · Q32Show mark scheme →
AV = 220 V, P = 2000 W
BV = 220 V, P = 2200 W
CV = 230 V, P = 2000 W
DV = 230 V, P = 2300 W
Mark scheme
54Feb / March 2017 · Paper 12 · Q33Show mark scheme →
Aenergy / J: 3.0, time / s: 2.0
Benergy / J: 3.0, time / s: 8.0
Cenergy / J: 48, time / s: 2.0
Denergy / J: 48, time / s: 8.0
Mark scheme
55Oct / Nov 2016 · Paper 11 · Q33Show mark scheme →
A0.0129 A, 18 600 Ω
B0.0770 A, 3100 Ω
C12.9 A, 18.6 Ω
D12.9 A, 3100 Ω
Mark scheme
56Oct / Nov 2016 · Paper 13 · Q33Show mark scheme →
Acurrent 0.0129 A, resistance 18 600 Ω
Bcurrent 0.0770 A, resistance 3100 Ω
Ccurrent 12.9 A, resistance 18.6 Ω
Dcurrent 12.9 A, resistance 3100 Ω
Mark scheme
57May / June 2016 · Paper 11 · Q30Show mark scheme →
Athe current in the resistor and the potential difference across the resistor
Bthe resistance of the resistor and the current in the resistor
Cthe total charge passing through the resistor and the potential difference across the resistor
Dthe total charge passing through the resistor and the resistance of the resistor
Mark scheme
58May / June 2016 · Paper 12 · Q33Show mark scheme →
ABoth lamps light at less than their normal brightness.
BBoth lamps light at their normal brightness.
COnly the 240 V lamp lights.
DThe 10 V lamp blows.
Mark scheme
59May / June 2016 · Paper 13 · Q33Show mark scheme →
Athe force required to move a unit positive charge between the points
Bthe ratio of the energy dissipated between the points to the current
Cthe ratio of the power dissipated between the points to the current
Dthe ratio of the power dissipated between the points to the charge moved
Mark scheme
60Feb / March 2016 · Paper 12 · Q31Show mark scheme →
A0.48 W
B0.96 W
C1.92 W
D4.8 W
Mark scheme
61Feb / March 2016 · Paper 12 · Q33Show mark scheme →
A5.0 C
B60 C
C100 C
D6000 C
Mark scheme