The transformer
4.5.6What the syllabus asks of you
- Describe the structure and explain the principle of operation of a simple iron-cored transformer
- Use the terms primary, secondary, step-up and step-down
- Recall and use the equation Vp / Vs = Np / Ns where P and S refer to primary and secondary
- State the advantages of high-voltage transmission and explain why power losses in cables are smaller when the voltage is greater
Read the notes first
Chapter 4: The transformer
Drill this topic
Every question on The transformer, untimed, marked as you go.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
23 questions
1May / June 2026 · Paper 12 · Q35Show mark scheme →
Airon
Bplastic
Ccopper
Dsteel
Mark scheme
2Oct / Nov 2025 · Paper 11 · Q35Show mark scheme →
A0.069 V
B0.11 V
C9.6 V
D15 V
Mark scheme
3May / June 2025 · Paper 11 · Q34Show mark scheme →
Ato decrease the current in the cable; d.c.
Bto decrease the current in the cable; a.c.
Cto increase the current in the cable; d.c.
Dto increase the current in the cable; a.c.
Mark scheme
4May / June 2025 · Paper 12 · Q35Show mark scheme →
AThere is an alternating current (a.c.) in the primary coil and a direct current (d.c.) in the secondary coil.
BThere is a larger current in the secondary coil than in the primary coil.
CThere is a changing magnetic field in the iron core.
DIn the iron core there is an alternating current from the primary coil to the secondary coil.
Mark scheme
5May / June 2024 · Paper 11 · Q36Show mark scheme →
A20
B30
C600
D12 000
Mark scheme
6May / June 2024 · Paper 12 · Q36Show mark scheme →
A1 and 2
B1 and 4
C2 and 3
D3 and 4
Mark scheme
7Oct / Nov 2023 · Paper 11 · Q32Show mark scheme →
A11
B54
C500
D11 500
Mark scheme
8Oct / Nov 2023 · Paper 11 · Q34Show mark scheme →
Aplastic; d.c. supply
Bplastic; a.c. supply
Ciron; d.c. supply
Diron; a.c. supply
Mark scheme
9Oct / Nov 2022 · Paper 12 · Q36Also set in Oct / Nov 2022 Paper 11Show mark scheme →
AThe changing magnetic field in the transformer induces an e.m.f. in the secondary coil.
BThe core of the transformer is made of iron because iron is a good electrical conductor.
CThe transformer converts alternating current to direct current.
DThe transformer converts direct current to alternating current.
Mark scheme
10May / June 2022 · Paper 11 · Q37Show mark scheme →
A0.12 V
B6.0 V
C12 V
D96 V
Mark scheme
11May / June 2022 · Paper 12 · Q40Also set in May / June 2022 Paper 11, May / June 2016 Paper 12Show mark scheme →
Ahigh power loss in the cables, high current in the cables
Bhigh power loss in the cables, low current in the cables
Clow power loss in the cables, high current in the cables
Dlow power loss in the cables, low current in the cables
Mark scheme
12Oct / Nov 2021 · Paper 12 · Q34Also set in Oct / Nov 2021 Paper 11Show mark scheme →
Apower / W: 120, current / A: 0.20
Bpower / W: 120, current / A: 5.0
Cpower / W: 480, current / A: 0.80
Dpower / W: 480, current / A: 1.3
Mark scheme
13May / June 2021 · Paper 12 · Q38Also set in May / June 2021 Paper 11Show mark scheme →
AThe lamp does not light at all.
BThe lamp lights at normal brightness.
CThe lamp lights dimly.
DThe lamp lights up brightly and then goes out.
Mark scheme
14Oct / Nov 2020 · Paper 12 · Q36Show mark scheme →
Ahigher frequency a.c.
Blower frequency a.c.
Ccurrent in one direction only
Dthe same frequency a.c.
Mark scheme
15Oct / Nov 2019 · Paper 11 · Q37Show mark scheme →
A5
B180
C2900
D100 000
Mark scheme
16Oct / Nov 2019 · Paper 12 · Q37Show mark scheme →
Ato decrease the current and the potential difference from the power station
Bto decrease the current and increase the potential difference from the power station
Cto increase the current and the potential difference from the power station
Dto increase the current and decrease the potential difference from the power station
Mark scheme
17Oct / Nov 2018 · Paper 11 · Q34Show mark scheme →
A10
B14
C4000
D580 000
Mark scheme
18Oct / Nov 2018 · Paper 11 · Q35Show mark scheme →
Aalternating, low
Balternating, very high
Cdirect, low
Ddirect, very high
Mark scheme
19Oct / Nov 2018 · Paper 12 · Q34Show mark scheme →
Aa cable from a bicycle dynamo to a lamp
Ba household lighting cable
Ca power cable between towns
Dan electric cooker cable
Mark scheme
20May / June 2018 · Paper 12 · Q36Show mark scheme →
AThe output voltage is equal to 6.0 V.
BThe output voltage is greater than 6.0 V.
CThe output voltage is less than 6.0 V but more than zero.
DThere is no output voltage.
Mark scheme
21May / June 2017 · Paper 11 · Q39Show mark scheme →
AThe lamp does not light at all.
BThe lamp lights dimly.
CThe lamp lights at normal brightness.
DThe lamp lights up brightly and then goes out.
Mark scheme
22May / June 2017 · Paper 12 · Q38Show mark scheme →
Acopper
Biron
Cplastic
Dsteel
Mark scheme
23Oct / Nov 2016 · Paper 11 · Q35Show mark scheme →
Airon / copper
Biron / steel
Csteel / copper
Dsteel / iron
Mark scheme