Potential dividers
10.3What the syllabus asks of you
- understand the principle of a potential divider circuit
- recall and use the principle of the potentiometer as a means of comparing potential differences
- understand the use of a galvanometer in null methods
- explain the use of thermistors and light-dependent resistors in potential dividers to provide a potential difference that is dependent on temperature and light intensity
Read the notes first
Chapter 10: Potential dividers
Drill this topic
Every question on Potential dividers, untimed, marked as you go.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
75 questions
1May / June 2026 · Paper 11 · Q36Show mark scheme →
A3.0 V
B6.0 V
C9.0 V
D12.0 V
Mark scheme
2May / June 2026 · Paper 13 · Q35Show mark scheme →
Avoltmeter reading decreases; change needed to resistance of variable resistor decrease
Bvoltmeter reading decreases; change needed to resistance of variable resistor increase
Cvoltmeter reading increases; change needed to resistance of variable resistor decrease
Dvoltmeter reading increases; change needed to resistance of variable resistor increase
Mark scheme
3Oct / Nov 2025 · Paper 12 · Q35Show mark scheme →
A20 V
B24 V
C36 V
D40 V
Mark scheme
4Oct / Nov 2025 · Paper 12 · Q36Show mark scheme →
ACircuit A
BCircuit B
CCircuit C
DCircuit D
Mark scheme
5May / June 2025 · Paper 11 · Q35Show mark scheme →
A0.36 mA
B0.40 mA
C0.48 mA
D0.80 mA
Mark scheme
6May / June 2025 · Paper 13 · Q35Show mark scheme →
A0.0 V
B2.0 V
C4.0 V
D6.0 V
Mark scheme
7May / June 2025 · Paper 14 · Q36Show mark scheme →
ACircuit diagram A
BCircuit diagram B
CCircuit diagram C
DCircuit diagram D
Mark scheme
8Oct / Nov 2024 · Paper 11 · Q32Show mark scheme →
A6.0 kΩ
B18 kΩ
C26 kΩ
D30 kΩ
Mark scheme
9Oct / Nov 2024 · Paper 11 · Q37Show mark scheme →
A0.50 V
B0.75 V
C1.0 V
D1.1 V
Mark scheme
10Oct / Nov 2024 · Paper 13 · Q35Show mark scheme →
AThe current I1 must be zero.
BThe current I2 must be zero.
CThe p.d. across YZ must be zero.
DThe resistance of the external circuit must be zero.
Mark scheme
11May / June 2024 · Paper 11 · Q33Show mark scheme →
ACircuit A
BCircuit B
CCircuit C
DCircuit D
Mark scheme
12May / June 2024 · Paper 13 · Q37Show mark scheme →
AThe wire XY was replaced with one of lower resistance.
B$E_2$ was increased.
C$E_1$ was decreased.
D$R$ was decreased.
Mark scheme
13Oct / Nov 2023 · Paper 11 · Q37Show mark scheme →
AR1 doubled, R2 doubled
BR1 doubled, R2 halved
CR1 halved, R2 doubled
DR1 halved, R2 halved
Mark scheme
14Oct / Nov 2023 · Paper 12 · Q33Show mark scheme →
Atemperature: increase; light intensity: increase
Btemperature: no change; light intensity: decrease
Ctemperature: decrease; light intensity: no change
Dtemperature: decrease; light intensity: decrease
Mark scheme
15Oct / Nov 2023 · Paper 12 · Q37Show mark scheme →
AAny non-zero reading on the galvanometer means the cell has an e.m.f. of 1.5 V.
BThe battery does not need to have an e.m.f. of 6.0 V.
CThe cell may be connected either way round between X and Y.
DThe galvanometer does not need a scale calibrated in amperes.
Mark scheme
16Oct / Nov 2023 · Paper 13 · Q37Show mark scheme →
AThe e.m.f. of the driver cell must be less than the e.m.f. of the new cell.
BThe galvanometer must have a large resistance.
CThe internal resistance of the new cell must be zero.
DThe resistance per unit length of the wire QR must be constant.
Mark scheme
17May / June 2023 · Paper 11 · Q36Show mark scheme →
ACircuit A: two resistors X in series, output across lower X
BCircuit B: resistors X and 2X in series, output across 2X
CCircuit C: resistor X in series with parallel combination of X and 2X, output across parallel combination
DCircuit D: resistor X in series with parallel combination of X and 2X, output across parallel combination
Mark scheme
18May / June 2023 · Paper 11 · Q37Show mark scheme →
Asliding contact at end P: 0 V; sliding contact at end Q: 3 V
Bsliding contact at end P: 0 V; sliding contact at end Q: 6 V
Csliding contact at end P: 3 V; sliding contact at end Q: 3 V
Dsliding contact at end P: 3 V; sliding contact at end Q: 6 V
Mark scheme
19May / June 2023 · Paper 12 · Q37Show mark scheme →
Adecreasing the supply voltage
Bincreasing the supply voltage
Cmoving the sliding contact to the left
Dmoving the sliding contact to the right
Mark scheme
20May / June 2023 · Paper 13 · Q37Show mark scheme →
AQR/4
BQR/3
C2QR/3
D3QR/4
Mark scheme
21Feb / March 2023 · Paper 12 · Q37Show mark scheme →
A2.65 V
B3.18 V
C6.35 V
D10.8 V
Mark scheme
22Oct / Nov 2022 · Paper 11 · Q36Show mark scheme →
A1.1 Ω
B2.1 Ω
C4.0 Ω
D8.0 Ω
Mark scheme
23Oct / Nov 2022 · Paper 11 · Q37Show mark scheme →
ADecrease the temperature of the thermistor.
BIncrease the resistance of the variable resistor.
CReduce the intensity of light incident on the light-dependent resistor (LDR).
DReplace the fixed resistor with a 500 Ω resistor.
Mark scheme
24Oct / Nov 2022 · Paper 12 · Q36Show mark scheme →
A3.0 V
B6.0 V
C9.0 V
D12.0 V
Mark scheme
25Oct / Nov 2022 · Paper 12 · Q37Show mark scheme →
A4 mV
B5 mV
C15 mV
D16 mV
Mark scheme
26Oct / Nov 2022 · Paper 13 · Q37Show mark scheme →
AAdd a resistor of resistance 0.1 Ω in series with cell E.
BAdd a resistor of resistance 1000 Ω in series with cell E.
CAdd a resistor of resistance 10 Ω in series with the new source.
DAdd a resistor of resistance 800 Ω in series with the new source.
Mark scheme
27May / June 2022 · Paper 11 · Q37Show mark scheme →
ACircuit A
BCircuit B
CCircuit C
DCircuit D
Mark scheme
28May / June 2022 · Paper 12 · Q37Show mark scheme →
ACircuit A
BCircuit B
CCircuit C
DCircuit D
Mark scheme
29May / June 2022 · Paper 13 · Q38Show mark scheme →
AR_X larger, R_Y larger
BR_X larger, R_Y smaller
CR_X smaller, R_Y larger
DR_X smaller, R_Y smaller
Mark scheme
30Feb / March 2022 · Paper 12 · Q37Show mark scheme →
A2.0 Ω
B6.0 Ω
C12 Ω
D18 Ω
Mark scheme
31Oct / Nov 2021 · Paper 11 · Q38Show mark scheme →
A1/3
B3/4
C3/1
D4/3
Mark scheme
32Oct / Nov 2021 · Paper 12 · Q38Show mark scheme →
A3.0 V
B3.4 V
C4.5 V
D5.4 V
Mark scheme
33May / June 2021 · Paper 11 · Q37Show mark scheme →
A1.6 V
B2.4 V
C3.6 V
D4.0 V
Mark scheme
34May / June 2021 · Paper 11 · Q38Show mark scheme →
AThe e.m.f. of cell X must be lower than the e.m.f. of cell E.
BThe internal resistance of cell X must be known.
CThe lengths QS and QR must be determined accurately.
DThe resistance of the wire QR must be proportional to its length.
Mark scheme
35May / June 2021 · Paper 12 · Q38Show mark scheme →
A2.0 kΩ
B10 kΩ
C60 kΩ
D72 kΩ
Mark scheme
36May / June 2021 · Paper 13 · Q38Show mark scheme →
A30 Ω
B38 Ω
C50 Ω
D450 Ω
Mark scheme
37Feb / March 2021 · Paper 12 · Q37Show mark scheme →
A1/6
B1/3
C1/2
D2/3
Mark scheme
38Feb / March 2021 · Paper 12 · Q38Show mark scheme →
Agraph A
Bgraph B
Cgraph C
Dgraph D
Mark scheme
39Oct / Nov 2020 · Paper 11 · Q35Show mark scheme →
A
B
C
D
Mark scheme
40Oct / Nov 2020 · Paper 12 · Q37Show mark scheme →
A1.20 Ω
B1.80 Ω
C7.20 Ω
D14.4 Ω
Mark scheme
41Oct / Nov 2020 · Paper 12 · Q38Show mark scheme →
A0 V, 3 V
B0 V, 6 V
C3 V, 3 V
D3 V, 6 V
Mark scheme
42Oct / Nov 2020 · Paper 13 · Q38Show mark scheme →
A395 Ω
B405 Ω
C795 Ω
D805 Ω
Mark scheme
43May / June 2020 · Paper 11 · Q38Show mark scheme →
AAny non-zero reading on the galvanometer means the cell has an e.m.f. of 1.5 V.
BThe battery does not need to have an e.m.f. of 6.0 V.
CThe cell may be connected either way round between X and Y.
DThe galvanometer does not need a scale calibrated in amperes.
Mark scheme
44May / June 2020 · Paper 12 · Q3Show mark scheme →
Athe 0.5 Ω resistor in series with the galvanometer
Bthe 0.5 Ω resistor in parallel with the galvanometer and this combination placed in series with the 1 kΩ resistor
Cthe 1 kΩ resistor in parallel with the galvanometer
Dthe 1 kΩ resistor in parallel with the galvanometer and this combination placed in series with the 0.5 Ω resistor
Mark scheme
45May / June 2020 · Paper 12 · Q38Show mark scheme →
A1.3 V to 11.1 V
B1.3 V to 12.0 V
C1.5 V to 11.1 V
D1.5 V to 12.0 V
Mark scheme
46May / June 2020 · Paper 13 · Q38Show mark scheme →
A0 V to 3.0 V
B0 V to 4.0 V
C1.0 V to 3.0 V
D1.0 V to 4.0 V
Mark scheme
47Feb / March 2020 · Paper 12 · Q37Show mark scheme →
ACircuit A: cell with variable resistor in parallel with lamp
BCircuit B: cell with variable resistor in series with lamp
CCircuit C: potential divider with variable resistor and lamp
DCircuit D: potential divider with variable resistor and lamp
Mark scheme
48Oct / Nov 2019 · Paper 12 · Q37Show mark scheme →
A3.0 Ω
B5.0 Ω
C8.0 Ω
D18 Ω
Mark scheme
49May / June 2019 · Paper 11 · Q38Show mark scheme →
A0 – 6 V
B0 – 12 V
C6 – 12 V
D12 – 20 V
Mark scheme
50May / June 2019 · Paper 12 · Q37Show mark scheme →
A6.0 V
B8.0 V
C16.0 V
D18.0 V
Mark scheme
51May / June 2019 · Paper 13 · Q37Show mark scheme →
A62.5 Ω
B107 Ω
C210 Ω
D360 Ω
Mark scheme
52Feb / March 2019 · Paper 12 · Q38Show mark scheme →
A1.0 V
B1.2 V
C4.8 V
D5.0 V
Mark scheme
53Oct / Nov 2018 · Paper 11 · Q38Show mark scheme →
AGraph A: V/V against L/cm, straight line from origin (0,0) rising to 6 at L = 60 cm
BGraph B: V/V against L/cm, straight line from origin (0,0) rising to a value below 6 at L = 60 cm
CGraph C: V/V against L/cm, straight line from 6 at L = 0 falling to 0 at L = 60 cm
DGraph D: V/V against L/cm, straight line from a value below 6 at L = 0 falling to 0 at L = 60 cm
Mark scheme
54Oct / Nov 2018 · Paper 12 · Q38Show mark scheme →
AA potentiometer balance point results in zero current through the galvanometer.
BAt the balance point, the current through resistor R in both circuits is the same.
CThe electromotive force (e.m.f.) of cell X is larger than that of cell Y.
DThe value of the e.m.f. of each of the cells X and Y is less than 6 V.
Mark scheme
55Oct / Nov 2018 · Paper 13 · Q37Show mark scheme →
A100 Ω
B200 Ω
C400 Ω
D600 Ω
Mark scheme
56May / June 2018 · Paper 11 · Q36Show mark scheme →
AQ and R: 12.5; Q and S: 62.5; P and R: 37.5
BQ and R: 25.0; Q and S: 62.5; P and R: 37.5
CQ and R: 25.0; Q and S: 75.0; P and R: 37.5
DQ and R: 25.0; Q and S: 62.5; P and R: 12.5
Mark scheme
57May / June 2018 · Paper 12 · Q37Show mark scheme →
A90 Ω
B150 Ω
C250 Ω
D400 Ω
Mark scheme
58May / June 2018 · Paper 13 · Q37Show mark scheme →
A32 Ω
B49 Ω
C71 Ω
D128 Ω
Mark scheme
59May / June 2018 · Paper 13 · Q38Show mark scheme →
AL/x
Bx/L
C(L - x)/x
Dx/(L - x)
Mark scheme
60Feb / March 2018 · Paper 12 · Q36Show mark scheme →
AV_X falls, V_Y rises
BV_X falls, V_Y stays the same
CV_X rises, V_Y falls
DV_X rises, V_Y stays the same
Mark scheme
61Feb / March 2018 · Paper 12 · Q37Show mark scheme →
A1/6
B1/3
C1/2
D2/3
Mark scheme
62Oct / Nov 2017 · Paper 11 · Q38Show mark scheme →
AP − Q = R − S
BP − S = Q − R
CPQ = RS
DPS = QR
Mark scheme
63Oct / Nov 2017 · Paper 12 · Q38Show mark scheme →
A0 to 3 V
B0 to 4 V
C0 to 8 V
D0 to 9 V
Mark scheme
64May / June 2017 · Paper 11 · Q36Show mark scheme →
A9 V battery with 1 kΩ and 1 kΩ resistors in series, computer input voltage across the lower 1 kΩ resistor, switch in series with the upper 1 kΩ resistor
B9 V battery with 1 kΩ and 2 kΩ resistors in series, computer input voltage across the lower 2 kΩ resistor, switch in series with the upper 1 kΩ resistor
C9 V battery with 2 kΩ and 500 Ω resistors in series, computer input voltage across the lower 500 Ω resistor, switch in series with the lower 500 Ω resistor
D9 V battery with 500 Ω and 2 kΩ resistors in series, computer input voltage across the lower 2 kΩ resistor, switch in series with the lower 2 kΩ resistor
Mark scheme
65May / June 2017 · Paper 12 · Q37Show mark scheme →
Adecreases / decreases
Bdecreases / increases
Cincreases / decreases
Dincreases / increases
Mark scheme
66May / June 2017 · Paper 13 · Q36Show mark scheme →
AWhen R1 increases, it takes a greater proportion of V0, so V decreases.
BWhen R1 increases, the current through R1 and R2 decreases, so V increases.
CWhen R2 decreases, it takes a smaller proportion of V0, so V increases.
DWhen R2 increases, the current through R1 and R2 decreases, so V decreases.
Mark scheme
67Feb / March 2017 · Paper 12 · Q37Show mark scheme →
AR1 doubled, R2 doubled
BR1 doubled, R2 halved
CR1 halved, R2 doubled
DR1 halved, R2 halved
Mark scheme
68Oct / Nov 2016 · Paper 11 · Q36Show mark scheme →
AR1 – R3 = R2 – R4
BR1 × R3 = R2 × R4
CR1 – R4 = R2 – R3
DR1 × R4 = R2 × R3
Mark scheme
69Oct / Nov 2016 · Paper 12 · Q38Show mark scheme →
AGraph A: V decreases linearly from 4 to 2 as slider moves from X to Y
BGraph B: V increases linearly from 0 to 4 as slider moves from X to Y
CGraph C: V decreases linearly from 4 to 0 as slider moves from X to Y
DGraph D: V increases linearly from 2 to 4 as slider moves from X to Y
Mark scheme
70Oct / Nov 2016 · Paper 13 · Q36Show mark scheme →
AR1 – R3 = R2 – R4
BR1 × R3 = R2 × R4
CR1 – R4 = R2 – R3
DR1 × R4 = R2 × R3
Mark scheme
71May / June 2016 · Paper 11 · Q34Show mark scheme →
A1.3 V to 11.1 V
B1.3 V to 12.0 V
C1.5 V to 11.1 V
D1.5 V to 12.0 V
Mark scheme
72May / June 2016 · Paper 12 · Q36Show mark scheme →
AR_X larger, R_Y larger
BR_X larger, R_Y smaller
CR_X smaller, R_Y larger
DR_X smaller, R_Y smaller
Mark scheme
73May / June 2016 · Paper 12 · Q37Show mark scheme →
A0–2 V
B0–5 V
C2–3 V
D2–5 V
Mark scheme
74May / June 2016 · Paper 13 · Q36Show mark scheme →
A0 cm
B40 cm
C60 cm
D100 cm
Mark scheme
75Feb / March 2016 · Paper 12 · Q5Show mark scheme →
AThe potential difference between Q and Y is infinite.
BThe potential difference between Q and Y is zero.
CThe resistance between Q and Y is infinite.
DThe resistance between Q and Y is zero.
Mark scheme