The d.c. motor
4.5.5What the syllabus asks of you
- Know that a current-carrying coil in a magnetic field may experience a turning effect and that the turning effect is increased by increasing: (a) the number of turns on the coil (b) the current (c) the strength of the magnetic field
- Describe the operation of an electric motor, including the action of a split-ring commutator and brushes
Read the notes first
Chapter 4: The d.c. motor
Drill this topic
Every question on The d.c. motor, untimed, marked as you go.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
12 questions
1Oct / Nov 2025 · Paper 11 · Q32Show mark scheme →
Abattery
Bbrushes
Cdiode
Dsplit-ring commutator
Mark scheme
2May / June 2025 · Paper 12 · Q34Show mark scheme →
A1, 2 and 3
B1 and 2 only
C1 and 3 only
D2 and 3 only
Mark scheme
3Oct / Nov 2024 · Paper 12 · Q35Show mark scheme →
Athe armature
Bthe brushes
Cthe slip rings
Dthe split-ring commutator
Mark scheme
4May / June 2024 · Paper 12 · Q35Show mark scheme →
Aa coil
Ba magnet
Ca slip ring
Da split-ring commutator
Mark scheme
5Oct / Nov 2023 · Paper 11 · Q33Show mark scheme →
Aslip ring; parallel to the magnetic field
Bslip ring; perpendicular to the magnetic field
Csplit ring; parallel to the magnetic field
Dsplit ring; perpendicular to the magnetic field
Mark scheme
6May / June 2020 · Paper 12 · Q39Show mark scheme →
Aincreasing the current in the coils of the electromagnet
Bincreasing the current in the rectangular coil
Creversing the current in the electromagnet
Dincreasing the number of turns on the rectangular coil
Mark scheme
7May / June 2019 · Paper 11 · Q36Show mark scheme →
Aincreasing the number of turns in the coil
Breversing the current
Cusing a lower voltage supply
Dusing a stronger magnet
Mark scheme
8Oct / Nov 2017 · Paper 12 · Q33Show mark scheme →
Ato decrease the electric current
Bto increase the electric current
Cto reverse the magnetic field
Dto strengthen the magnetic field
Mark scheme
9May / June 2017 · Paper 12 · Q36Show mark scheme →
Ait ensures that the current is the same in all parts of a series circuit
Bit generates an alternating electric current
Cit produces a force on a current-carrying coil
Dit reverses the direction of the current in the coil of a motor
Mark scheme
10Oct / Nov 2016 · Paper 11 · Q33Show mark scheme →
Agreater resistance: P; greater turning effect: P
Bgreater resistance: P; greater turning effect: Q
Cgreater resistance: Q; greater turning effect: P
Dgreater resistance: Q; greater turning effect: Q
Mark scheme
11May / June 2016 · Paper 11 · Q35Show mark scheme →
Aevery quarter turn
Bevery half turn
Cevery full turn
Devery two turns
Mark scheme
12May / June 2016 · Paper 12 · Q32Show mark scheme →
Aincrease the current in the coil and increase the number of turns in the coil
Breverse both the magnetic field and the current in the coil
Creverse the magnetic field and decrease the current in the coil
Dreverse the magnetic field and increase the current in the coil
Mark scheme