IAL Physics Unit 4 (WPH14): full past-paper analysis, Jan 2020 – Jun 2026, with October 2026 predictions
Edexcel IAL Physics Unit 4: Further Mechanics, Fields and Particles (WPH14). 19 papers, updated 3 October 2026.
Scope and method
All 19 WPH14 papers from January 2020 to June 2026 were analysed question by question against their mark schemes: 1,710 marks in total.
- Papers: Jan 2020, Jun 2020, Jan 2021, Jun 2021, Oct 2021, Jan 2022, Jun 2022, Oct 2022, Jan 2023, Jun 2023, Oct 2023, Jan 2024, Jun 2024, Oct 2024, Jan 2025, Jun 2025, Oct 2025, Jan 2026, Jun 2026. Each is 90 marks.
- Not counted: the June and October 2019 papers. They are the legacy WPH04 specification (80 marks) and are summarised in the appendix.
- Classification: every marking point was assigned to one of ten topic areas. Multi-topic questions were split by marking point, and each MCQ counts as 1 mark for its topic.
- Accuracy: the split involves judgement, so per-topic figures carry roughly ±2 marks. Question-type counts (“in 16 of 19 papers”) count a paper once if that type appears anywhere in it, MCQ or structured.
| Spec topic | Topic area used in this analysis |
|---|---|
| Further mechanics | Momentum and collisions; circular motion |
| Electric and magnetic fields | Electric fields and potential; capacitors; magnetic forces (F = BIl, F = Bqv, r = p/BQ); electromagnetic induction |
| Nuclear and particle physics | Rutherford scattering and nuclear notation; accelerators, electron beams and de Broglie; particle physics (standard model, conservation laws, ΔE = c2Δm, relativistic lifetimes) |
| Synoptic | Unit 1–2 content used inside Unit 4 questions |
Sources: Pearson Edexcel question papers and mark schemes. A-grade boundaries are Pearson’s published figures for October 2022 and October 2024.
Paper format and how it has changed
Every paper is 90 marks in 1 hour 45 minutes: ten 1-mark MCQs in Section A, then 80 marks of structured questions in Section B.
- Section B has fragmented. From Jan 2020 to Jun 2023 every paper had 8 or 9 structured questions. Oct 2023, Jan 2024 and Oct 2025 had 12 each; Jan 2025 and Jun 2026 had 10.
- More short questions. Up to Jun 2023, no paper had more than two questions worth 4 marks or fewer. Oct 2023 had 4, Jan 2024 had 5, and Jan, Jun and Oct 2025 had 3 each.
- Long questions persist. The largest were 18 marks (Jan 2025 Q20, capacitors) and 17 marks (Oct 2024 Q17 and Q18). Oct 2025 was the first paper with no question above 11 marks.
- One starred 6-mark extended response per paper. It is marked on indicative content (up to 4 marks) plus linkage and sustained reasoning (up to 2 marks).
- Method marks dominate calculations. Mark schemes award “use of” marks for correct substitution and carry errors forward. “Show that” answers need one more significant figure than the value given, and g = 9.81 N kg−1 is expected.
- No fixed topic order. Any topic can open Section B, and the MCQs mix all three spec topics.
- Grade boundaries swing widely. The A boundary was 71/90 in October 2024 but 48/90 in October 2022.
Topic weighting
Particle physics and electric fields each average about 14 of the 90 marks, and the four field topics together (electric fields, capacitors, magnetic forces, induction) average about 42.
Particle physics and electric fields each average about 14 of the 90 marks
Marks per topic in each WPH14 paper, sorted by average, with each topic’s lowest-to-highest range. The outlined column is June 2026.
| Topic | Jan 20 | Jun 20 | Jan 21 | Jun 21 | Oct 21 | Jan 22 | Jun 22 | Oct 22 | Jan 23 | Jun 23 | Oct 23 | Jan 24 | Jun 24 | Oct 24 | Jan 25 | Jun 25 | Oct 25 | Jan 26 | Jun 26 | Avg | Range |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Particle physics | 8 | 11 | 16 | 13 | 21 | 25 | 10 | 17 | 18 | 8 | 11 | 9 | 16 | 20 | 7 | 11 | 12 | 16 | 17 | 14.0 | 7–25 |
| Electric fields | 13 | 6 | 18 | 19 | 13 | 12 | 8 | 16 | 9 | 14 | 24 | 5 | 12 | 14 | 13 | 15 | 18 | 18 | 17 | 13.9 | 5–24 |
| Momentum | 9 | 12 | 13 | 13 | 9 | 6 | 17 | 10 | 12 | 15 | 8 | 10 | 14 | 16 | 9 | 4 | 10 | 12 | 8 | 10.9 | 4–17 |
| Capacitors | 10 | 7 | 6 | 16 | 10 | 11 | 11 | 9 | 12 | 7 | 8 | 14 | 10 | 6 | 19 | 13 | 10 | 12 | 7 | 10.4 | 6–19 |
| Induction | 12 | 10 | 8 | 7 | 7 | 14 | 10 | 7 | 11 | 13 | 13 | 13 | 11 | 7 | 10 | 9 | 13 | 12 | 11 | 10.4 | 7–14 |
| Circular motion | 9 | 15 | 5 | 9 | 9 | 13 | 7 | 16 | 10 | 13 | 9 | 9 | 6 | 8 | 11 | 12 | 6 | 11 | 12 | 10.0 | 5–16 |
| Accelerators | 13 | 7 | 6 | 2 | 5 | 2 | 11 | 2 | 7 | 8 | 7 | 10 | 10 | 8 | 14 | 15 | 5 | 3 | – | 7.1 | 0–15 |
| Magnetic forces | 4 | 9 | 6 | 10 | 5 | 5 | 5 | 8 | 9 | 7 | 8 | 10 | 4 | 8 | 6 | 7 | 8 | 4 | 10 | 7.0 | 4–10 |
| Rutherford | 10 | 8 | 1 | 1 | 8 | 2 | 6 | 4 | 2 | 2 | 2 | 7 | 3 | 2 | 1 | 2 | 7 | 2 | 7 | 4.1 | 1–10 |
| Unit 1–2 synoptic | 2 | 5 | 11 | – | 3 | – | 5 | 1 | – | 3 | – | 3 | 4 | 1 | – | 2 | 1 | – | 1 | 2.2 | 0–11 |
Every Unit 4 topic scored in all 19 papers except accelerators, which had no marks in June 2026. Mechanics (momentum and circular motion) averages about 21 marks a paper, and nuclear and particle physics about 25.
Recurring question types
Four question types appeared in all 19 papers, and fourteen more in at least 11 of them. Counts marked ≈ involve a judgement about borderline parts.
| Question type | Papers (of 19) | Typical marks | Example |
|---|---|---|---|
| Explain electromagnetic induction (flux change → e.m.f. → current → force or field → Lenz) | 19 | 2–6 | Jan 2024 Q21 (induction hob) |
| ΔE = c2Δm with MeV or GeV ↔ kg | 19 | 1–4 | Oct 2023 Q21(c) |
| Conservation of charge, baryon number and lepton number | 19 (14 structured) | 2–6 | Jan 2021 Q13(b) |
| Rutherford scattering: results, conclusions or closest approach | 19 (mostly MCQ) | 1–8 | Jun 2026 Q15 |
| Linac or cyclotron: explain or calculate | 18 | 2–13 | Jun 2025 Q16 |
| 2D momentum by components or vector diagram | 16 | 4–8 | Jan 2024 Q20(b) |
| Capacitor exponential (e^−t/RC or ln form) | 16 | 2–4 | Jan 2025 Q20 |
| Energy stored, ½CV2 or ½QV | ≈15 | 1–3 | Oct 2025 Q12 |
| Induced e.m.f. from rate of change of flux linkage, including Blv | 15 | 3–6 | Jun 2023 Q16 |
| Nucleon, proton and neutron counts; nuclear equations | ≈14 | 1–2 | Jun 2020 Q17(b)(i) |
| Uniform field: E = V/d and F = EQ, then F = ma or suvat | ≈13 | 3–6 | Oct 2025 Q21 |
| r = p/BQ calculation, often from kinetic energy in MeV | ≈13 | 2–4 | Jan 2021 Q15(b) |
| Why high energies probe nucleons (de Broglie wavelength) | ≈13 | 1–4 | Jan 2020 Q19(c) |
| Field-line or equipotential drawing | 12 | 2–3 | Oct 2024 Q12 |
| Electric potential V = kQ/r, including closest approach | ≈12 | 2–4 | Oct 2025 Q19 |
| Elastic or inelastic: compare total kinetic energy | 11 | 2–4 | Jun 2024 Q15 |
| Relativistic lifetime of fast particles (muons) | 11 | 1–5 | Jan 2021 Q14(a) |
| Thermionic emission | 11 | 1–2 | Jun 2020 Q18(a) |
| Coulomb’s law force | ≈10 | 2–3 | Jun 2023 Q17 |
| Banked track, conical pendulum or banking aircraft | 9 | 4–9 | Oct 2024 Q17(b) |
| Vertical circle: forces at top and bottom | 8 (incl. MCQs) | 4–6 | Jan 2025 Q15 |
| Sketch a capacitor charge or discharge graph | 8 | 2–4 | Oct 2021 Q14(c) |
| Derive a = v2/r with a vector diagram | 5 | 4–5 | Jan 2024 Q17(a) |
| Derive r = p/BQ | 2 | 2 | Jun 2023 Q12(a) |
Methods the mark schemes reward
Most marks follow a fixed route per task. Where a mark scheme accepts alternatives, they are listed together.
| Task | Method credited | Seen in |
|---|---|---|
| State conservation of momentum | Total momentum is constant, provided no resultant external force acts; the condition carries its own mark | Jan 2021 Q17(c), Jan 2023 Q14, Jan 2024 Q20 |
| 2D collision | Resolve parallel and perpendicular to the initial direction, or a scale vector diagram with a stated scale | Oct 2022 Q16, Jan 2023 Q14, Jun 2024 Q15 |
| Elastic check | Total kinetic energy before and after (½mv2 or p2/2m), compared, with a conclusion matching the numbers | Jan 2021 Q17(b)(ii), Jun 2023 Q14, Jan 2024 Q20 |
| Derive Ek = p2/2m | Substitute v = p/m into ½mv2 | Jun 2021 Q12 |
| Impulse | F = Δp/Δt, counting both velocities in a rebound; area under an F–t graph | Jan 2021 Q17(a), Jun 2022 Q11 |
| Derive a = v2/r | Vector diagram of v at two points with Δv; small angle so Δv = vΔθ; Δθ = ωΔt; a = vω = v2/r | Jun 2020 Q16(a), Jan 2022 Q15(a), Jan 2024 Q17(a) |
| Banked track, conical pendulum, banking aircraft | Resolve vertically (N cos θ = mg) and horizontally (N sin θ = mv2/r), then divide to get tan θ = v2/rg | Jan 2020 Q14(b), Oct 2021 Q12, Oct 2024 Q17(b) |
| Vertical circle | Top: N + mg = mv2/r. Bottom: N − mg = mv2/r. Minimum speed from N = 0 | Jan 2022 Q15, Jun 2023 Q15, Oct 2025 Q16 |
| Field lines | Radial: at least 4 evenly spaced lines with arrows. Uniform: at least 3 parallel, evenly spaced lines from plate to plate | Jun 2023 Q17(a), Jan 2026 Q18(a) |
| Closest approach | Initial kinetic energy, converted from MeV to J, equals kQq/r; solve for r | Jun 2020 Q14(c), Jan 2021 Q18(a), Oct 2023 Q15 |
| Charged particle between plates | E = V/d, F = EQ, a = F/m; time from the horizontal motion; s = ½at2 | Oct 2023 Q22, Oct 2025 Q21 |
| Hanging charged sphere | Resolve the tension so tan θ = F/mg, then Coulomb’s law | Jan 2022 Q13, Jun 2023 Q17 |
| Time constant from a graph | Any of: read-off at 0.37V0; two points in the ln equation; tangent at t = 0; gradient −1/RC of a ln graph | Jan 2023 Q16, Jun 2024 Q12, Jan 2025 Q20 |
| Charging calculation | V_C = V0(1 − e^−t/RC), which is not on the formula sheet, with V_R = V0 − V_C | Jan 2024 Q18(a) |
| Charge or energy from graphs | Q = area under I–t; energy = area under V–Q; energy change = ½CV12 − ½CV22 | Jan 2022 Q14, Jun 2025 Q17 |
| Capacitor tolerance | Apply the stated percentage to C before using ½CV2 | Jan 2024 Q11, Oct 2025 Q12 |
| r = p/BQ from an energy | MeV to J, p = √(2mEk), then r = p/BQ; an alpha has Q = 2e | Jan 2021 Q15(b), Jun 2023 Q12(b) |
| Derive r = p/BQ | Equate Bqv = mv2/r, substitute p = mv | Jun 2023 Q12(a), Jun 2026 Q14 |
| Velocity selector | EQ = BQv, so v = E/B = V/Bd | Oct 2022 Q18, Jan 2023 Q17(a) |
| Cyclotron timing | T = 2πm/BQ from r = p/BQ and v = 2πr/T; energy gained per gap crossing = QV | Jan 2020 Q19, Jan 2025 Q17 |
| Maximum induced e.m.f. | ε = NAΔB/Δt from the steepest gradient (tangent) of the B–t or flux–t graph | Jan 2022 Q18(b), Jun 2023 Q16 |
| Moving conductor | Area swept per second = lv, so ε = Blv | Oct 2023 Q17, Jan 2024 Q16 |
| Generator | Peak e.m.f. ∝ ω and period ∝ 1/ω: halving ω halves the peak and doubles the period | Jan 2020 Q18(b), Jan 2026 Q17 |
| Conservation laws | Tabulate charge, baryon number and lepton number for every particle on both sides, then conclude | Jan 2021 Q13(b), Oct 2023 Q21 |
| Mass in MeV/c2 | Multiply by 1.60 × 10−13, then divide by c2 | Oct 2022 Q13(a), Oct 2023 Q21(c) |
| Annihilation | Two photons share the energy, conserving momentum; E = mc2 per particle, then f = E/h | Jun 2020 Q12(b), Jun 2021 Q18 |
| Relativistic lifetime | Show the non-relativistic distance (speed × lifetime) is too short, so time dilation must lengthen the lifetime | Jan 2021 Q14(a), Oct 2024 Q13 |
| Speed check | v from ½mv2 comes out above c, so a relativistic treatment is needed | Jun 2021 Q18, Jan 2023 Q18, Jun 2024 Q16(a) |
The 6-mark extended-response question
The starred question rotates among six topics. Induction is the most frequent (6 of 19) but has not been starred since Jan 2024, while Rutherford was starred in both Oct 2025 and Jun 2026.
Totals: induction 6, accelerators 5, Rutherford 4, particle physics 2, circular motion 1, capacitors 1.
| Paper | Question | Topic | What was asked | Indicative points (summary) |
|---|---|---|---|---|
| Jun 2026 | Q15 | Rutherford | Observations from alpha scattering and the conclusions drawn | Most undeflected, so mostly empty space; some deflected, so concentrated charge; very few beyond 90°, so most mass in a tiny nucleus |
| Jan 2026 | Q16(c) | Particle physics | How detector tracks show a photon creating a particle–antiparticle pair | No track for the photon (uncharged); tracks curve oppositely, so opposite charges; equal radii, so equal momentum and mass (r = p/BQ) |
| Oct 2025 | Q19(a) | Rutherford | Evidence and conclusions from the scattering experiments | Observations paired with conclusions, as in Jun 2026 |
| Jun 2025 | Q16(a) | Accelerators | How a linac and a cyclotron use a p.d. to accelerate particles | Field across each gap accelerates; alternating p.d. reverses while particles are shielded in tubes or dees; cyclotron magnetic field returns particles to the gap |
| Jan 2025 | Q17(c) | Accelerators | How a cyclotron raises protons’ energy (a.c. p.d. and magnetic field) | Gap field accelerates; magnetic force perpendicular to velocity gives a semicircle in each dee; p.d. reverses every half cycle, so every crossing accelerates |
| Oct 2024 | Q14 | Capacitors | The V–t graph for a capacitor charging through a resistor | Charge builds, V_C rises, V_R falls, current falls, charging slows until V_C = V0 and I = 0 |
| Jun 2024 | Q16(b) | Accelerators | How a linac produces high-energy electrons (a.c. supply, tube lengths) | Gap fields accelerate; polarity switches while inside tubes; constant frequency, so equal time per tube and longer tubes; equal lengths once v ≈ c |
| Jan 2024 | Q21(a) | Induction | Why a kettle on an induction coil heats with a.c. | a.c. gives a changing field and flux linkage; e.m.f. induced; eddy currents in the metal dissipate energy |
| Oct 2023 | Q16 | Induction | The e.m.f.–time graph for a magnet dropped through a coil | e.m.f. only while flux linkage changes; zero at the centre; reversed second pulse (Lenz), larger and shorter as the magnet speeds up |
| Jun 2023 | Q15(b) | Circular motion | Car in a vertical loop: positions at the force graph’s maximum and minimum | Centripetal force constant; N − W at the bottom (maximum); N + W at the top (minimum) |
| Jan 2023 | Q15(a) | Induction | How a balance reading changed as a wire moved between magnets | Wire cuts flux, e.m.f. drives a current, force on the wire opposes motion (Lenz), equal and opposite force on the magnets |
| Oct 2022 | Q14 | Induction | Magnet falling through a copper tube and a slit tube | Changing flux, eddy currents, opposing force, slower fall; the slit breaks the current path, so less braking |
| Jun 2022 | Q13(a) | Accelerators | Why linac tube spacing increases, then becomes nearly equal | As Jun 2024 |
| Jan 2022 | Q16(c) | Particle physics | Energy and momentum in K− + p → Ω− + K+ + K0 | Total energy conserved; kinetic energy becomes extra rest mass; vector momentum conserved, so products must move |
| Oct 2021 | Q13(a) | Rutherford | Why the results surprised Rutherford and led to the nuclear model | Plum pudding predicts only small deflections; large-angle scattering needs a small, massive, charged nucleus |
| Jun 2021 | Q14 | Induction | Why a force-meter reading rose as a magnet fell through a copper tube | Eddy currents oppose the magnet’s motion; by Newton’s third law the tube is pushed down |
| Jan 2021 | Q15(a) | Accelerators | Role of electric and magnetic fields in a cyclotron | As Jan 2025 |
| Jun 2020 | Q15(b)(i) | Induction | How a p.d. on an input coil charges a capacitor via an output coil | Changing current gives changing flux linking the output coil; e.m.f. induced; current charges the capacitor |
| Jan 2020 | Q15(b) | Rutherford | Whether scattering results justified replacing the plum pudding model | Observations and conclusions, plus why spread-out charge cannot give large deflections |
Unstarred 6-mark parts are almost always multi-step calculations: 2D momentum (Jun 2020 Q17, Jun 2023 Q14, Oct 2024 Q18), maximum induced e.m.f. (Jan 2022 Q18), an elastic check (Jan 2025 Q19) or a generator current (Jun 2026 Q20). The exceptions are Jun 2022 Q16(a), three Rutherford observations with their conclusions, and Jan 2021 Q13(b), conservation laws in a decay.
Section A: multiple choice
Section A draws on about twenty recurring themes. Alpha-scattering conclusions, capacitor calculations and magnetic-force questions each had an MCQ in 12 of the 19 papers.
| MCQ theme | Papers with one (of 19) | The usual trap |
|---|---|---|
| Alpha scattering: valid or invalid conclusion | 12 | “The nucleus contains neutrons” and “electrons orbit in shells” are not conclusions |
| Capacitor charge, energy, time or graphs | 12 | Energy ∝ V2; the battery supplies QV but the capacitor stores ½QV |
| F = BIl, F = Bqv, Fleming’s left-hand rule | 12 | sin θ; zero force when parallel to the field |
| Nucleon and neutron counts, decay changes | 11 | N = A − Z |
| Units, scalars and vectors | 11 | Potential and capacitance are scalars |
| Impulse and momentum change | 9 | A rebound gives Δp = m(u + v) |
| Linac or cyclotron statement | 9 | Cyclotron frequency does not depend on speed |
| Particle classification and quark content | 9 | Mesons are quark + antiquark; leptons are fundamental |
| Induction: flux linkage, Lenz, e.m.f. | 9 | e.m.f. = gradient of the flux-linkage graph |
| Thermionic emission | 8 | A heated filament, not light |
| Electrons as probes (de Broglie) | 7 | Short wavelength, not “creating new particles” |
| Ek = p2/2m scaling | 7 | Same p, double m: half the Ek |
| Conservation laws in a particle equation | 7 | Check charge, baryon and lepton number on both sides |
| Inverse-square scaling of F, E and V | 7 | V goes as 1/r, not 1/r2 |
| Field patterns and equipotentials | 6 | Equipotentials are perpendicular to field lines |
| Radius of a charged particle’s path | 6 | At equal speed an alpha’s radius is twice a proton’s |
| Radians and angular velocity | 5 | rpm × 2π/60 |
| Circular motion: forces or Δv direction | 5 | Δv and a point to the centre |
| Elastic vs inelastic | 5 | Momentum is conserved in both |
| Annihilation or pair-production energy | 4 | Threshold photon energy 2mc2 |
Every MCQ, by paper
| Paper | Q1–Q10 |
|---|---|
| Jun 2026 | 1 neutrons in an isotope; 2 radians to degrees; 3 GeV s−1 as a unit of power; 4 elastic collision; 5 meson quark content; 6 field lines between two charges; 7 capacitor charging; 8 impulse of a braking cyclist; 9 deflection in a magnetic field; 10 Coulomb force with doubled separation |
| Jan 2026 | 1 neutron and proton numbers; 2 which is a scalar (potential); 3 why high-energy electrons; 4 F = BIl sin θ; 5 field and potential between two protons; 6 thermionic emission (vacuum diode); 7 alpha-scattering conclusion; 8 linac drift tubes; 9 alpha vs proton radius in B; 10 vertical-circle forces |
| Oct 2025 | 1 field lines round a proton; 2 identify X by conservation; 3 Ek = p2/2m with momentum halved; 4 capacitance is a scalar; 5 muon lifetime; 6 induced e.m.f. in coils; 7 positron emission; 8 cyclotron frequency; 9 rebound impulse; 10 Δv in circular motion |
| Jun 2025 | 1 protons and neutrons in an isotope; 2 capacitance from a V–Q graph; 3 field of a proton; 4 muons and relativity; 5 alpha-scattering detector positions; 6 thermionic emission; 7 annihilation photon energy; 8 why high-energy electrons; 9 fission fragment momentum and Ek; 10 Δv in circular motion |
| Jan 2025 | 1 degrees to radians; 2 identify a meson; 3 Coulomb force; 4 positron vs electron; 5 large-angle scattering; 6 e.m.f. in linked coils; 7 pair-production photon energy; 8 bubble-chamber track; 9 E–r graph for a sphere; 10 capacitor energy ratio |
| Oct 2024 | 1 electron gun; 2 units of a vector; 3 fundamental vs composite; 4 alpha decay nucleon change; 5 electron in B at an angle; 6 p = √(2mEk); 7 inelastic collision; 8 cyclotron statement; 9 alpha-scattering conclusions; 10 proton–antiproton annihilation energy |
| Jun 2024 | 1 SI base unit; 2 momentum vectors in a decay; 3 Fleming’s left-hand rule; 4 current from F = BIl; 5 cyclotron statement; 6 discharge time t = RC ln(V0/V); 7 invalid alpha-scattering conclusion; 8 area under F–t; 9 proton path losing energy in B; 10 alpha vs proton radius |
| Jan 2024 | 1 N = A − Z; 2 thermionic emission; 3 F = Bqv sin θ; 4 short wavelength of fast electrons; 5 E vs distance between plates; 6 is a pion decay possible; 7 capacitor combinations; 8 Lenz, magnet moved away; 9 helium atom rebound impulse; 10 alpha path near a nucleus |
| Oct 2023 | 1 nuclear notation; 2 impulse FΔt; 3 why linac tubes lengthen; 4 unit of flux; 5 invalid alpha-scattering conclusion; 6 kaon-decay tracks; 7 radius r = p/BQ; 8 angular velocity; 9 capacitor discharge time; 10 humpback bridge forces |
| Jun 2023 | 1 thermionic emission; 2 Q = CV; 3 β+ decay; 4 units of impulse; 5 why high energies; 6 fundamental particle; 7 MeV/c2 to kg; 8 invalid alpha-scattering conclusion; 9 β− decay equation; 10 F = BIl at an angle |
| Jan 2023 | 1 proton and neutron quarks; 2 rpm to angular velocity; 3 alpha decay nucleon change; 4 track direction in B; 5 alpha-scattering conclusion; 6 dipole field pattern; 7 cyclotron statement; 8 Ek = p2/2m; 9 rebound momentum change; 10 proton vs helium nucleus accelerated |
| Oct 2022 | 1 antiproton mass and charge; 2 valid alpha-scattering conclusion; 3 thermionic emission; 4 field pattern between two charges; 5 energy from a Q–V graph; 6 base units of the tesla; 7 quark combination by charge; 8 linac operation; 9 mass from p and Ek; 10 linked coils with a.c. |
| Jun 2022 | 1 fundamental particle; 2 proton–antiproton products; 3 capacitor energy ∝ V2; 4 Coulomb force; 5 F = BIl component; 6 electrons probing nuclei; 7 muon lifetime; 8 cyclotron; 9 units of the farad; 10 linked coils e.m.f. graph |
| Jan 2022 | 1 nucleon and neutron numbers; 2 antiproton charge and mass; 3–4 trolley collision, momentum and elasticity; 5 thermionic emission (CRT); 6 electron deflection between plates; 7 forces on a coil; 8 alpha scattering; 9 cyclotron energy; 10 Moon’s orbit (circular motion) |
| Oct 2021 | 1 fundamental particle; 2 elastic collision; 3 Ek = p2/2m; 4 E vs r graph; 5 flux linkage of a rotating coil; 6 field strength from a V–r graph; 7 battery work vs energy stored; 8 electrons as probes; 9 π− quark content; 10 F = BIl sin θ graph |
| Jun 2021 | 1 fundamental particle; 2 alpha-scattering conclusion; 3 neutrino interaction equation; 4 pentaquark combinations; 5 electron diffraction; 6 induced e.m.f. in a coil; 7 elastic collision of identical spheres; 8 electron between plates; 9 F = Bqv; 10 why high energies |
| Jan 2021 | 1 which is not a vector; 2 Ek = p2/2m scaling; 3 nucleon notation; 4 kg to GeV/c2; 5 capacitor charging graphs; 6 positron vs muon curvature; 7 field from two charges; 8 F = BIl on a balance; 9 field between plates; 10 C from a discharge graph |
| Jun 2020 | 1 field direction from two charges; 2 conservation laws in a decay; 3 capacitor charge; 4 base units of the farad; 5 gas molecule momentum change; 6 stationary oil drop; 7 force on a proton in B; 8 Coulomb force scaling; 9 angular velocity from rpm; 10 Lenz’s law |
| Jan 2020 | 1 neutron decay equation; 2 potential at a new distance; 3 rebound momentum change; 4 field from equipotentials; 5 potential between plates; 6 pair production maximum mass; 7 F = BIl direction; 8 zero resultant force between charges; 9 merging momenta; 10 thermionic emission |
Question-by-question breakdown
Every structured question, oldest paper first, with its sub-parts, marks and the method credited. Marks for each part are in square brackets; * marks the starred 6-mark question. MCQs are listed in the Section A tables above.
January 2020 (9 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Nuclear notation | Producing technetium from molybdenum | Complete a nuclear equation using proton and nucleon numbers from a periodic-table extract [3] |
| 12 | 6 | Particle physics | Passage on the history of particle physics | Classify the particles in the passage as baryons, mesons or leptons, with quark-model reasoning [6] |
| 13 | 9 | Momentum (+ Unit 1 energy) | Jumping toy with a compressed spring | (a) show spring energy ≈ 0.1 J [2]; (b) test conservation of momentum from calculated speeds [5]; (c) was kinetic energy conserved [2] |
| 14 | 9 | Circular motion | Go-kart track with banked semicircular ends | (a) show friction meets the design criteria, F = mv2/r [2]; (b)(i) show tan θ = 2v2/gd by resolving [3]; (b)(ii) calculate θ [2]; (c) advantages of banking [2] |
| 15 | 7 | Rutherford | Geiger and Marsden, 1908 | (a) why a vacuum [1]; *(b) whether the results justified replacing the plum pudding model [6] |
| 16 | 9 | Electric fields | Spiders rising on charged silk in Earth’s field | (a) polarity of the charge [1]; (b) initial acceleration from F = EQ, W = mg, F = ma [5]; (c) charge on 1 m2 of Earth’s surface from E = kQ/r2 [3] |
| 17 | 10 | Capacitors | Night light that dims as a capacitor discharges | (a) choose C using V = V0e^(−t/RC) [4]; (b) effect of the LED’s behaviour on the dimming time [3]; (c) why “stores charge” is an incomplete description [3] |
| 18 | 12 | Induction | School a.c. generator | (a) explain the observation using induction and Lenz’s law [4]; (b)(i) sketch the output at half the angular velocity [2]; (b)(ii) explain: half the peak, double the period [2]; (b)(iii) number of turns from ε = BANω [4] |
| 19 | 15 | Accelerators (+ magnetic) | Lawrence’s first cyclotron, 1931 | (a)(i) derive the orbit time t = 2πm/BQ [3]; (a)(ii) why it allows a fixed-frequency supply [4]; (b) time to accelerate a proton from energy per crossing [5]; (c) why high energies probe nucleons [3] |
June 2020 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 4 | Magnetic forces | Model motor, coil at 20° to the field | Resultant moment of the magnetic forces: F = BIl × perpendicular distance [4] |
| 12 | 5 | Particle physics | PET scanning | (a) name the process (annihilation) [1]; (b) maximum gamma wavelength from ΔE = c2Δm, E = hf, c = fλ [4] |
| 13 | 4 | Particle physics | Zweig’s 1964 “aces” model | Compare it with the standard quark model [4] |
| 14 | 9 | Rutherford (+ electric fields) | Alpha scattering by a thin foil | (a) how the results gave the nuclear model [2]; (b) why the sign of the central charge was undetermined [4]; (c) closest approach to a platinum nucleus, Ek = kQq/r [3] |
| 15 | 16 | Induction, capacitors (+ Unit 1 work) | Mechanical vs electric mouse trap | (a) work done setting the trap ≈ 0.5 J [2]; *(b)(i) how a p.d. on the input coil charges the capacitor [6]; (b)(ii) maximum output p.d. ≈ 600 V from ε = NΔΦ/Δt [3]; (c) which trap stores more energy, using ½CV2 [5] |
| 16 | 14 | Circular motion | Fairground ride with aeroplanes on cables | (a) derive a = v2/r with a vector diagram [4]; (b)(i) free-body diagram [1]; (b)(ii) show 4 rotations take ≈ 3 s by resolving the tension [4]; (b)(iii) judge two students’ claims [5] |
| 17 | 14 | Momentum, nuclear | Cloud-chamber tracks from a radon decay chain | (a) state a reason from the tracks [1]; (b)(i) complete the nuclear equation [2]; (b)(ii) momentum vector diagram [2]; (b)(iii) velocity of the lead ion by momentum conservation [6]; (c) which track came first [3] |
| 18 | 14 | Accelerators (+ magnetic, Unit 2 waves) | Hospital radiotherapy linac | (a) thermionic emission [2]; (b)(i) electron energy at exit [3]; (b)(ii) why later tubes are equal [2]; (c) how standing waves form [3]; (d) B to bend the beam through 270°, r = p/BQ [4] |
January 2021 (9 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 4 | Capacitors | Two 32 µF capacitors on 6.0 V | (a) total charge, Q = CV [2]; (b) total energy, ½CV2 [2] |
| 12 | 5 | Circular motion | Coin in a rotating washing-machine drum | Contact force at the bottom: v from the period, then N = mv2/r + mg [5] |
| 13 | 8 | Particle physics | Antineutron decaying by emitting a positron | (a) energy conservation via the mass difference [2]; (b) charge, baryon and lepton number conservation [6] |
| 14 | 7 | Particle physics | Rossi and Hall’s 1940 muon observations | (a) consistency with relativity: non-relativistic distance vs observed [5]; (b) why muons are not mesons [2] |
| 15 | 10 | Accelerators, magnetic | 1937 cyclotron producing an isotope | *(a) role of electric and magnetic fields [6]; (b) B for alphas of given Ek: p = √(2mEk), r = p/BQ [4] |
| 16 | 10 | Induction (+ Unit 2 resistivity) | Tokamak plasma at Culham | (a) how a steadily rising coil current induces a plasma current [4]; (b)(i) show plasma resistance from R = ρl/A [2]; (b)(ii) heating power [4] |
| 17 | 12 | Momentum | Two table-hockey pucks | (a) average force from impulse [3]; (b)(i) speed after collision [4]; (b)(ii) elastic check [3]; (c) the no-external-force assumption [2] |
| 18 | 9 | Electric fields (Rutherford context) | Alpha particle approaching a nucleus | (a) maximum acceleration at closest approach: Ek = kQq/r, Coulomb’s law, a = F/m [5]; (b) compare with an alpha reflected straight back [4] |
| 19 | 15 | Electric fields (+ Unit 1 Stokes’ law) | Millikan’s oil-drop experiment | (a)(i) show the radius formula from terminal velocity [3]; (a)(ii) radius [2]; (a)(iii) charge from mg = EQ, E = V/d [4]; (b) do results support quantised charge [3]; (c) was Millikan’s viscosity too large or too small [3] |
June 2021 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 6 | Circular motion, magnetic forces | Faraday’s 1821 motor | (a) angular velocity of the wire [3]; (b) force on the wire, F = BIl [3] |
| 12 | 6 | Momentum, electric fields | Sloan and Lawrence’s linac (mercury ions) | (a) derive Ek = p2/2m [2]; (b) ion momentum at the next drift tube from W = QV [4] |
| 13 | 6 | Circular motion (+ Unit 1 energy) | Toy car loop-the-loop | Minimum speed at the top (mg = mv2/r) combined with energy conservation [6] |
| 14 | 6 | Induction | Magnet falling through a copper tube on a force meter | *Why the force-meter reading increased: eddy currents, Lenz, Newton’s third law [6] |
| 15 | 10 | Momentum | Deflecting an asteroid with a spacecraft | (a) momentum vector diagram [2]; (b) spacecraft momentum ≈ 107 N s [2]; (c) deflection angle [2]; (d) perpendicular velocity component [2]; (e) compare with another method’s Δp [2] |
| 16 | 14 | Electric fields | Opposite point charges 8.0 cm apart | (a) field midway by superposition [3]; (b)(i) add equipotentials [3]; (b)(ii) assess a claim about free test charges [4]; (c) p.d. between two points from V = kQ/r [4] |
| 17 | 16 | Capacitors | Student capacitor investigation | (a) circuit to charge, discharge and measure [3]; (b)(i) sketch V_R against t [2]; (b)(ii) show V = V0 − V0e^(−t/RC) [3]; (b)(iii) deduce C (R = 330 kΩ) [4]; (b)(iv) charge [2]; (b)(v) energy [2] |
| 18 | 16 | Particle physics, magnetic | Anderson’s 1932 positron photograph | (a) positron properties as the electron’s antiparticle [3]; (b) magnetic field direction [3]; (c)(i) show the speed is relativistic [3]; (c)(ii) B from r = 3.7 cm [3]; (d) annihilation gamma frequency [4] |
October 2021 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 4 | Electric fields | Field around a helium nucleus | (a) potential at 26.6 × 10−12 m, V = kQ/r [3]; (b) one assumption made [1] |
| 12 | 9 | Circular motion | 18th-century conical-pendulum clock | (a) add the two forces on the bob [2]; (b)(i) derive ω = √(g/l cos θ) by resolving [4]; (b)(ii) is the period as required [3] |
| 13 | 8 | Rutherford | Rutherford’s gold-foil experiments | *(a) why the results surprised Rutherford and led to the nuclear model [6]; (b) why the foil had to be very thin [2] |
| 14 | 9 | Capacitors | Model railway controller backed up by a capacitor | (a) how power is maintained when contact is lost [3]; (b) time to fall to 4.0 V, ln form [2]; (c) sketch I against t [4] |
| 15 | 10 | Momentum, induction (+ Unit 1 energy) | Launched roller coaster with magnetic braking fins | (a)(i) show launch speed ≈ 40 m s−1 from impulse [2]; (a)(ii) can it reach the top, by energy [3]; (b) why the fin slows in the magnet gap: eddy currents, Lenz [5] |
| 16 | 11 | Electric fields, particle physics | Spark chamber and cosmic-ray muons | (a) field lines between plates [3]; (b)(i) show force on an ion ≈ 2.6 × 10−13 N from E = V/d, F = EQ [3]; (b)(ii) can the ion cause further ionisation [2]; (c) why muons reach the ground (time dilation) [3] |
| 17 | 14 | Accelerators, particle physics | Collider fed by a linac | (a) why a constant-frequency a.c. supply works [4]; (b)(i) show omega baryon mass ≈ 1700 MeV/c2 [4]; (b)(ii) kinetic energy of one omega baryon [3]; (c) assess a suggestion using baryon number [3] |
| 18 | 15 | Particle physics, magnetic, momentum | Positive pion decaying in a detector | (a) two signs of positive charge [2]; (b) why the anti-muon goes clockwise (spiral tightens) [3]; (c) field direction [1]; (d) pion path radius, r = p/BQ [3]; (e)(i) decay equation [1]; (e)(ii) momentum conservation by vector diagram [5] |
January 2022 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Electric fields | Negative point charge | Draw the radial field lines [3] |
| 12 | 4 | Momentum (Newton’s laws) | Hovering helicopter | Explain the hover using Newton’s laws and the momentum given to the air [4] |
| 13 | 8 | Electric fields | Two charged balloons on threads | (a)(i) show repulsion ≈ 1 × 10−3 N by resolving the tension [4]; (a)(ii) show charge ≈ 2 × 10−7 C, Coulomb’s law [2]; (b) potential at 0.30 m, V = kQ/r [2] |
| 14 | 11 | Capacitors | Charging circuit with two ammeters | (a) check the initial current, I = V/R [2]; (b) how the second ammeter’s current varies [2]; (c) capacitance from the graph [3]; (d) charge after 30 s [2]; (e) maximum energy stored [2] |
| 15 | 12 | Circular motion | Poi ball swung in a vertical circle | (a) derive a = v2/r from the velocity at two points [5]; (b) acceleration from the rotation rate [3]; (c) cord tension at top vs bottom [4] |
| 16 | 14 | Particle physics | K− meson hitting a stationary proton to make an Ω− | (a) detection by ionisation [2]; (b)(i) baryon and meson structure [2]; (b)(ii) field direction [1]; (b)(iii) Ω− charge and baryon number by conservation [3]; *(c) how energy and momentum are conserved [6] |
| 17 | 14 | Particle physics, magnetic | Muon experiment at Fermilab | (a) muon classification [2]; (b) the other two decay products [2]; (c) muon vs electron mass via E = mc2 [3]; (d)(i) why GeV/c is a momentum unit [2]; (d)(ii) check a ring-radius claim, r = p/BQ [3]; (d)(iii) why muons in the ring live longer [2] |
| 18 | 14 | Induction | Faraday’s law, ε = −d(Nφ)/dt | (a) name Nφ and its unit [2]; (b) maximum e.m.f. from the steepest B–t gradient [6]; (c) Lenz’s law with an aluminium disc [6] |
June 2022 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Momentum | Flyboard hovering on water jets | Water speed or flow from FΔt = Δp with the weight [3] |
| 12 | 8 | Momentum | Snooker: white ball strikes black | (a) define inelastic [1]; (b) why velocity vectors can stand in for momenta (equal masses) [2]; (c) scale vector diagram: does the black ball reach the pocket [5] |
| 13 | 9 | Accelerators | Electron linac | *(a) why tube spacing increases, then becomes almost equal [6]; (b) fixed target vs colliding beams for the heaviest new particles [3] |
| 14 | 11 | Magnetic, particle physics | Tracks in a 7.0 T detector | (a) negative pion’s momentum from r = p/BQ [4]; (b) two signs that the kaon is neutral [2]; (c) quark structure of antiproton and π− [2]; (d) proton mass in GeV/c2 [3] |
| 15 | 9 | Capacitors | RC input to an integrated circuit | (a)(i) sketch V_C against t [2]; (a)(ii) how V_R varies [2]; (a)(iii) show V_C = 5 − 5e^(−t/RC) [2]; (b) choose a capacitor using the ln form (R = 68 kΩ) [3] |
| 16 | 13 | Rutherford, electric fields | Alpha particles on gold foil | (a) three observations with conclusions [6]; (b)(i) show closest approach ≈ 5 × 10−14 m [4]; (b)(ii) field strength there, E = kQ/r2 [3] |
| 17 | 12 | Circular motion (+ Unit 1 projectiles) | Olympic hammer throw | (a)(i) free-body diagram [2]; (a)(ii) why the motion is circular [2]; (a)(iii) acceleration, a = v2/r [3]; (b) would the throw break the record, by projectile motion [5] |
| 18 | 15 | Momentum, induction | Electromagnetic braking of a glider | (a)(i) show momentum ≈ 0.3 N s from light-gate data [3]; (a)(ii) velocity at the second gate [3]; (b)(i) why a current flows in the plate [2]; (b)(ii) why the glider slows (Lenz) [2]; (c)(i) show the Ek loss is proportional to thickness [2]; (c)(ii) why thicker plates brake more [3] |
October 2022 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 6 | Particle physics | Identifying a pion decay product | (a) meson quark structure [1]; (b) one property of leptons [1]; (c) test a student’s identification with conservation laws [4] |
| 12 | 8 | Capacitors | Defibrillator | (a) complete the current–time graph while charging [4]; (b) does the design meet a timing requirement, exponential form [4] |
| 13 | 9 | Particle physics | Z boson at CERN’s proton–antiproton collider | (a) show m_Z ≈ 100 m_p from GeV/c2 [4]; (b) why high energies were needed, ΔE = c2Δm [3]; (c) explain an observed lifetime (relativity) [2] |
| 14 | 6 | Induction | Magnet falling through a copper tube and a slit tube | *Explain the different fall times: eddy currents, Lenz [6] |
| 15 | 12 | Rutherford, electric fields | Why Rutherford used alpha particles | (a) alpha vs beta or gamma [3]; (b)(i) field lines between two equipotentials [3]; (b)(ii) is the 10 V equipotential in the right place (V ∝ 1/r) [3]; (b)(iii) potential-energy gain in eV [3] |
| 16 | 12 | Momentum, circular motion | Hockey stick striking a ball | (a) speed of the stick’s heel, v = ωr [3]; (b)(i) momentum conservation by scale vector diagram [5]; (b)(ii) elastic check [4] |
| 17 | 13 | Circular motion | Aeroplane circling while waiting to land | (a) derive a = v2/r with a vector diagram [5]; (b)(i) how banking gives a horizontal circle [4]; (b)(ii) radius at 530 m s−1 [4] |
| 18 | 14 | Electric fields, magnetic | Mass spectrometer | (a)(i) anode–cathode p.d. from E = V/d [2]; (a)(ii) show ion speed ≈ 5 × 105 m s−1 from QV = ½mv2 [4]; (b)(i) magnetic field direction in the velocity selector [2]; (b)(ii) B = E/v [3]; (c) why only one isotope reaches the detector, r = mv/BQ [3] |
January 2023 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 4 | Particle physics | Muon decay | (a) one positron–electron difference [1]; (b) is a given decay possible: charge and lepton number [3] |
| 12 | 7 | Electric fields | Point charge and a −4.5 nC charge | (a) equipotentials at equal p.d. intervals [2]; (b) force, Coulomb’s law [2]; (c) work done moving the −4.5 nC charge, W = QΔV [3] |
| 13 | 9 | Circular motion | Banking aeroplane | (a)(i) show radius ≈ 800 m by resolving the lift [5]; (a)(ii) time to turn through 90° [2]; (b) vertical motion if the lift is increased [2] |
| 14 | 10 | Momentum | Spreadsheet model of a collision | (a) state the principle [2]; (b)(i) elastic check [3]; (b)(ii) momentum conservation from the values [5] |
| 15 | 11 | Induction | Wire moved between magnets on a balance | *(a) how the balance reading changed [6]; (b) maximum p.d. from the rate of change of flux [5] |
| 16 | 12 | Capacitors | Faulty charge–discharge circuit | (a) two reasons the circuit failed [2]; (b)(i) resistance from the discharge graph [3]; (b)(ii) average current over 30 s, ΔQ/Δt [4]; (b)(iii) energy dissipated, ½CV12 − ½CV22 [3] |
| 17 | 11 | Magnetic, electric fields, de Broglie | Thomson’s e/m experiment with crossed fields | (a)(i) show v = V/Bd [3]; (a)(ii) show v ≈ 3 × 107 m s−1 [2]; (a)(iii) is the e/m value accurate [3]; (b) how electron diffraction changed ideas about electrons [3] |
| 18 | 16 | Particle physics | Discovery of the bottom and top quarks | (a)(i) why a sixth quark was predicted [3]; (a)(ii) the two categories of hadron [1]; (b)(i) advantage of colliding beams [4]; (b)(ii) maximum KE of a top quark [3]; (b)(iii) is a top quark with 1.2 × 10−7 J relativistic [3]; (c) assess a suggestion about relativistic lifetime [2] |
June 2023 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 5 | Particle physics | CERN’s 2022 pentaquark | Quark combinations and charges for a five-quark particle [5] |
| 12 | 6 | Magnetic forces | Charged particle on a circular path | (a) derive r = p/BQ [2]; (b) B for an alpha with r = 0.096 m, from its kinetic energy [4] |
| 13 | 6 | Accelerators | Linacs and cyclotrons | (a) use of electric fields in a linac and the a.c. frequency [4]; (b) why the cyclotron field is perpendicular to the dees [2] |
| 14 | 10 | Momentum | 1930s alpha–proton collisions | (a) show proton momentum ≈ 5 × 10−20 N s at about 20° (2D) [6]; (b) elastic check [4] |
| 15 | 13 | Circular motion | Toy car driving inside a plastic ball | (a)(i) show ω ≈ 40 rad s−1 [3]; (a)(ii) was 86 mm the radius or diameter, F = mω2r [4]; *(b) car’s position at maximum and minimum force [6] |
| 16 | 13 | Induction | Rotating search coil | (a) why a p.d. is produced [2]; (b) show initial flux ≈ 9 × 10−5 Wb, φ = BA [3]; (c) maximum p.d. (5000 turns) from the graph [4]; (d) a statement about Lenz’s law [4] |
| 17 | 14 | Electric fields | Charged sphere hanging between plates at 5000 V | (a) field lines round a charged sphere [3]; (b)(i) show charge ≈ 10 nC, V = kQ/r [2]; (b)(ii) show force ≈ 5 × 10−4 N, E = V/d, F = EQ [3]; (b)(iii) show θ ≈ 1° [3]; (c) separation of two charged spheres, Coulomb’s law [3] |
| 18 | 13 | Capacitors, momentum (+ Unit 1 energy) | Capacitor used to time a collision | (a) confirm a value from the ln I–t graph [4]; (b)(i) sphere B’s maximum speed from its rise [3]; (b)(ii) contact time from the discharge [2]; (b)(iii) test a claim using impulse [4] |
October 2023 (12 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Circular motion | Playground roundabout | ω and v = ωr [3] |
| 12 | 3 | de Broglie | Electron with Ek = 7.2 × 10−16 J | p = √(2mEk), then λ = h/p [3] |
| 13 | 3 | Magnetic forces | Current-carrying rod in a field | F = BIl from the balance reading [3] |
| 14 | 4 | Circular motion | Passenger who feels “thrown outwards” | Newton’s first law and the centripetal force [4] |
| 15 | 6 | Electric fields (Rutherford context) | Alpha particle approaching a gold nucleus | (a) minimum distance, Ek = kQq/r [4]; (b) maximum force, Coulomb’s law [2] |
| 16 | 6 | Induction | Magnet dropped through a coil, data logger | *Explain the e.m.f.–time graph [6] |
| 17 | 6 | Induction | Copper rod pushed along rails | (a) e.m.f. = Bdv (B = 150 mT) [3]; (b) direction of the induced e.m.f. [3] |
| 18 | 7 | Capacitors | Measuring capacitance (150 kΩ) | (a) is C within tolerance, from discharge data [4]; (b) assess a suggested improvement [3] |
| 19 | 7 | Momentum | Curling stones | (a) show v ≈ 1.3 m s−1 by momentum conservation [4]; (b) elastic check [3] |
| 20 | 10 | Electric fields | Gordon’s electrostatic bells | (a) force on the sphere: C = 4πε0r, Q = CV, E = V/d, F = EQ [5]; (b) why the sphere oscillates [3]; (c) why it moves in a storm (induced charge) [2] |
| 21 | 10 | Particle physics | Cosmic-ray pions decaying to muons | (a) pion quark structure [1]; (b) two other conservation laws [4]; (c) muon mass in kg from MeV/c2 [3]; (d) lifetime of fast pions (time dilation) [2] |
| 22 | 15 | Electric fields, magnetic | Electron beam tube for e/m | (a) why the path between plates is parabolic [3]; (b)(i) show exit speed ≈ 1.7 × 107 m s−1, eV = ½mv2 [3]; (b)(ii) vertical deflection with F = EQ and s = ½at2 [5]; (b)(iii) assess e/m using r = p/BQ [4] |
January 2024 (12 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Capacitors | Capacitor with a stated tolerance | Maximum energy stored, ½CV2 with the tolerance applied [3] |
| 12 | 3 | Particle physics | Bubble-chamber tracks after a collision | Interpret the tracks: neutral particles leave none [3] |
| 13 | 4 | Electric fields | Helonium: a proton joining a helium ion | (a) initial force, Coulomb’s law [2]; (b) field strength of the helium ion, E = kQ/r2 [2] |
| 14 | 5 | Rutherford | Alpha scattering on thin metal foil | Results and their conclusions [5] |
| 15 | 4 | de Broglie | Electron diffraction through graphite | λ = h/p with p from the accelerating p.d. [4] |
| 16 | 4 | Induction | Aeroplane wing in Earth’s field | e.m.f. across the wing tips, ε = Blv with the vertical field component [4] |
| 17 | 9 | Circular motion | Model aeroplane on a wire | (a) derive a = v2/r [5]; (b) will the wire break: tension from mv2/r and mg [4] |
| 18 | 10 | Capacitors | Charging through 168 kΩ from 6.0 V | (a)(i) C from the charging curve, V = V0(1 − e^(−t/RC)) [4]; (a)(ii) sketch I against t with values [3]; (b) effect of a change on charging time [3] |
| 19 | 8 | Magnetic (+ Unit 2 photons) | Auroras and radio interference | (a) electron speed for 560 nm emission, E = hc/λ = ½mv2 [3]; (b) would circling electrons interfere with a radio signal: f = Bq/2πm [5] |
| 20 | 9 | Momentum | Alpha–helium collision | (a) state the principle [2]; (b)(i) show helium speed ≈ 5.6 × 106 m s−1 by components [4]; (b)(ii) elastic check [3] |
| 21 | 8 | Induction | Induction cooker | *(a) why the kettle heats with a.c. [6]; (b) why an egg cooks only where it touches the pan [2] |
| 22 | 13 | Particle physics, accelerators, magnetic | Unstable particles from collisions | (a)(i) K− quark structure [2]; (a)(ii) K− mass in kg [3]; (b)(i) how a cyclotron makes a high-energy beam [4]; (b)(ii) B from the cyclotron’s diameter and energy, r = p/BQ [4] |
June 2024 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 4 | Nuclear notation, particle physics | Chadwick’s beryllium experiment | (a) complete the nuclear equation [2]; (b) criticise “the neutron is fundamental” using its quark structure [2] |
| 12 | 9 | Capacitors | Measuring the charging current | (a) add an ammeter to the circuit [1]; (b)(i) show C ≈ 0.02 F from the I–t graph [3]; (b)(ii) charge when fully charged [3]; (b)(iii) energy stored [2] |
| 13 | 9 | Circular motion (+ Unit 1 forces on a slope) | Coin on a rotating plastic disc | (a) show maximum friction ≈ 0.02 N [4]; (b)(i) angular velocity of the disc [2]; (b)(ii) is the estimate suitable, F = mω2r [3] |
| 14 | 11 | Particle physics | Hypothetical leptoquarks | (a) quark structure of baryons and mesons [2]; (b)(i) baryon and lepton numbers of a leptoquark [5]; (b)(ii) show the maximum creatable mass ≈ 3 × 10−24 kg, ΔE = c2Δm [3]; (b)(iii) why none have been observed [1] |
| 15 | 12 | Momentum | Pucks on an air table | (a) how the air table makes momentum conserved [2]; (b)(i) was the angle between paths 90°, by components [5]; (b)(ii) elastic check [5] |
| 16 | 12 | Accelerators, particle physics | CERN’s planned LHeC | (a) show the electrons are relativistic (½mv2 gives v > c) [3]; *(b) how a linac produces high-energy electrons [6]; (c) why high energies probe protons [3] |
| 17 | 12 | Electric fields | Electrostatic tug for removing old satellites | (a)(i) add equipotentials [3]; (a)(ii) label the 0 V equipotential [1]; (b)(i) minimum energy for an electron to leave, W = QV [3]; (b)(ii) test an estimate with Coulomb’s law, F = ma and suvat [4]; (c) suggest a reason [1] |
| 18 | 11 | Induction, electric fields | Car spark-plug ignition coil | (a) how a p.d. appears across the secondary when the switch opens [3]; (b) field strength in the gap from ε = NΔφ/Δt and E = V/d [5]; (c) why the current rises gradually (Lenz) [3] |
October 2024 (8 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Particle physics (units) | The “Amaterasu” cosmic ray | Convert its energy from eV to J and compare with an everyday energy [3] |
| 12 | 6 | Electric fields | Charges of +14 nC and −14 nC | (a) field lines round a positive charge [3]; (b) resultant field at R by superposition [3] |
| 13 | 5 | Particle physics | Atmospheric muons | (a) show distance in 2.20 µs ≈ 650 m [2]; (b) why most reach the ground (time dilation) [3] |
| 14 | 6 | Capacitors | Capacitor charging through a resistor | *Explain the V–t charging graph [6] |
| 15 | 12 | Magnetic forces, induction | Coil on an axle between magnets | (a)(i) why the coil turns clockwise, Fleming’s left-hand rule [2]; (a)(ii) resultant moment, F = BIl [3]; (b)(i) why the voltmeter may show a reading [2]; (b)(ii) does a quarter turn in a given time give a reading, ε = NΔφ/Δt [5] |
| 16 | 14 | Electric fields, accelerators | Charged ball accelerating between plates in a classroom demonstration | (a)(i) show a ≈ 0.8 m s−2 by suvat [2]; (a)(ii) show charge ≈ 2 × 10−9 C, V = kQ/r [2]; (a)(iii) is the electric force the only force: E = V/d, F = EQ, F = ma [4]; (b)(i) one similarity and two differences with a linac [3]; (b)(ii) why linac tubes lengthen [3] |
| 17 | 17 | Momentum, circular motion (+ Unit 1 density) | Toy aeroplane flying round on a thread | (a)(i) show the propeller moves ≈ 3 × 10−3 kg of air in 0.20 s [5]; (a)(ii) momentum of that air [2]; (a)(iii) forward force, F = Δp/Δt [2]; (b)(i) add the forces [2]; (b)(ii) show tan θ = v2/rg [3]; (b)(iii) time for one revolution [3] |
| 18 | 17 | Particle physics, magnetic, momentum | Σ+ decay in a bubble chamber | (a) B from r = p/BQ [2]; (b)(i) type of particle (baryon) [1]; (b)(ii) charge and lepton number conservation [4]; (b)(iii) neutron momentum by vector addition [6]; (b)(iv) sketch the tracks after the decay [4] |
January 2025 (10 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Particle physics | Proton–proton fusion in the Sun | Check charge, baryon and lepton number in p + p → p + n + e+ + ν [3] |
| 12 | 4 | Electric fields | Van de Graaff generator and a neon bulb | (a) show sphere charge ≈ 4.4 × 10−7 C, V = kQ/r [2]; (b) field at the bulb, E = kQ/r2 [2] |
| 13 | 3 | Magnetic forces | Power cable between pylons | Force on 90 m of cable carrying 700 A, F = BIl sin θ [3] |
| 14 | 6 | Electron beams, de Broglie | Cathode ray tube | (a) why heating releases electrons (thermionic emission) [2]; (b) accelerating p.d. for a given wavelength, λ = h/p and Ek = eV [4] |
| 15 | 10 | Circular motion | Washing-machine drum | (a)(i) show ω ≈ 150 rad s−1 [2]; (a)(ii) centripetal acceleration [2]; (b)(i) forces at top and bottom [2]; (b)(ii) how the contact force varies [3]; (b)(iii) path of water leaving the holes [1] |
| 16 | 7 | Electric fields (+ Unit 1 density) | Millikan’s oil drop | (a) field lines between plates [2]; (b) is the charge a whole multiple of e: mg = EQ, E = V/d [5] |
| 17 | 11 | Accelerators, magnetic | Proton cyclotron | (a) draw the spiral path [2]; (b) time in one dee, t = πm/BQ (B = 0.55 T) [3]; *(c) how the cyclotron raises the protons’ energy [6] |
| 18 | 9 | Induction | Magnetic key card swiped through a reader | (a) how the sensor detects pole orientation [4]; (b) can the reader resolve it, ε = NΔφ/Δt [5] |
| 19 | 9 | Momentum | Bumper cars with rubber strips | (a) why the strip reduces injury: longer contact time, smaller force [3]; (b) elastic or inelastic, via momentum then kinetic energy [6] |
| 20 | 18 | Capacitors | Charging and discharging with a voltage sensor | (a)(i) how the current varies while charging [4]; (a)(ii) sketch I against t with values [3]; (b)(i) show RC ≈ 60 s [2]; (b)(ii) percentage of p.d. left after a time [3]; (c) p.d. and time where two graph lines cross [4]; (d) charge on each of two connected capacitors [2] |
June 2025 (9 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 4 | Magnetic forces | Proton entering a 0.52 T field | (a) proton speed from the magnetic force [2]; (b) draw the circular path [2] |
| 12 | 3 | Momentum | Sphere rolled into two stationary spheres | One-dimensional momentum conservation [3] |
| 13 | 3 | Magnetic forces | Wire between magnets on a balance | F = BIl from the balance reading [3] |
| 14 | 9 | Particle physics | Discovery of the Ω−, 1964 | (a)(i) meson quark structure [1]; (a)(ii) baryon number and charge conservation [2]; (b) percentage difference between two masses [3]; (c) photographic evidence that a K0 formed [3] |
| 15 | 11 | Circular motion | Rotating dining turntable | (a)(i) show average ω ≈ 1.3 rad s−1 [3]; (a)(ii) same ω but different v at each radius [2]; (b)(i) test a claim with F = mω2r [4]; (b)(ii) which glass is more likely to slide [2] |
| 16 | 13 | Accelerators | Linac and cyclotron side by side | *(a) how both use a p.d. to accelerate particles [6]; (b)(i) show proton speed ≈ 2 × 107 m s−1 after the 4th gap [4]; (b)(ii) compare with the cyclotron’s exit speed [3] |
| 17 | 12 | Capacitors | Smoothing a power-supply output | (a) p.d. at the end of discharge [1]; (b)(i) is the output consistent with the resistor tolerance [5]; (b)(ii) change in energy stored during discharge [3]; (b)(iii) why a smaller time constant makes the output follow the supply [3] |
| 18 | 9 | Induction | Wireless phone charger | (a) how the phone charges [4]; (b)(i) maximum flux linkage of the coil [4]; (b)(ii) why not all the flux links [1] |
| 19 | 16 | Electric fields (+ Unit 1 density) | Lifting sand off solar panels electrostatically | (a) field lines [2]; (b)(i) why a sand particle moves [2]; (b)(ii) show the field strength, E = V/d [2]; (b)(iii) largest liftable particle: EQ vs weight from density [6]; (c)(i) forces on a particle [2]; (c)(ii) how tilting the panel helps [2] |
October 2025 (12 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 2 | Electric fields | Zinc nucleus, charge 4.8 × 10−18 C | Field strength at a distance, E = kQ/r2 [2] |
| 12 | 3 | Capacitors | 47 µF ± 20% on 400 V | Maximum energy, ½CV2 with +20% applied [3] |
| 13 | 3 | Accelerators, momentum | 1928 linac for heavy ions | Identify the ion from its final energy and momentum, Ek = p2/2m [3] |
| 14 | 6 | Induction | Aeroplane in Earth’s magnetic field | (a)(i) show the vertical field component ≈ 5.0 × 10−5 T [1]; (a)(ii) e.m.f. across the wingtips, ε = Blv [3]; (b) why the e.m.f. is zero in another case [2] |
| 15 | 7 | Particle physics | LHC tetraquarks, 2022 | (a) meson structure [1]; (b) a possible quark combination [1]; (c) compare its mass with two protons [3]; (d) why protons need very high speeds to make new particles [2] |
| 16 | 5 | Circular motion | Bucket of water swung in a vertical circle | (a) the two forces on the water [2]; (b) why there is a minimum speed, mg = mv2/r at the top [3] |
| 17 | 8 | Momentum | Colliding snow tubes | (a) show the angle ≈ 31° by components [4]; (b) elastic check [4] |
| 18 | 6 | Particle physics, magnetic | Pion decay in a bubble chamber | (a) how the field curves the π+ path [3]; (b)(i) what the missing track says about the second particle [2]; (b)(ii) why it moves opposite to the μ+ [1] |
| 19 | 11 | Rutherford, electric fields | Large-angle scattering in an evacuated chamber | *(a) evidence and conclusions [6]; (b)(i) show closest approach ≈ 4 × 10−14 m [3]; (b)(ii) maximum force, Coulomb’s law [2] |
| 20 | 7 | Capacitors | Phone touchscreen | (a)(i) show charge ≈ 1.3 × 10−4 C, Q = CV [2]; (a)(ii) is the screen sensitive enough, Q = Q0e^(−t/RC) [3]; (b) sketch the discharge current [2] |
| 21 | 11 | Electric fields, electron beams | Oscilloscope | (a) thermionic emission [1]; (b)(i) plate separation from E = V/d [2]; (b)(ii) show vertical acceleration ≈ 2.6 × 1015 m s−2 [3]; (b)(iii) would it give a 3.4 cm deflection, by suvat [5] |
| 22 | 11 | Magnetic forces, induction | Copper rod driven along rails by a current | (a) direction of motion, Fleming’s left-hand rule [2]; (b) B from F = BIl with the rod’s acceleration [4]; (c) why the current falls as the rod moves (induced e.m.f. opposes, Lenz) [5] |
January 2026 (9 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 2 | Magnetic forces | Alpha particle crossing a field | B from the magnetic force on the alpha [2] |
| 12 | 5 | Circular motion | Carousel | (a) show ω ≈ 0.4 rad s−1 [2]; (b) time to turn through a given angle [3] |
| 13 | 5 | Particle physics | Cosmic-ray pions decaying into muons | (a) lepton vs meson structure [1]; (b) charge and lepton number conservation [4] |
| 14 | 8 | Momentum | Collision of two spheres | (a) how to measure the angle ϕ [2]; (b)(i) show u ≈ 0.25 m s−1 by components [3]; (b)(ii) test the student’s claim [3] |
| 15 | 12 | Capacitors | Defibrillator | (a) enough energy to restart a heart, ½CV2 [3]; (b)(i) time for the current to fall to 8.0 A [2]; (b)(ii) charge left when discharge stops [3]; (c) charging-circuit resistance from its graph [4] |
| 16 | 11 | Particle physics | Pair production in a strong electric field | (a) two electron–positron differences [2]; (b) is the photon energy above 2mc2 [3]; *(c) how the tracks show pair production [6] |
| 17 | 12 | Induction | Classroom a.c. generator | (a)(i) sketch e.m.f. against time for two rotations [3]; (a)(ii) effect of turning faster [3]; (b) ε_max = BANω for a 9.5 cm × 12.0 cm coil [4]; (c) Lenz’s law and the coil’s motion [2] |
| 18 | 10 | Electric fields, momentum | Inkjet printer | (a) field lines round a point charge [2]; (b)(i) vertical velocity after the plates: E = V/d, F = EQ, a = F/m, v = at [5]; (b)(ii) is the horizontal impulse enough for the droplet to stick [3] |
| 19 | 15 | Circular motion, electric fields | Bohr model of hydrogen | (a) derive a = v2/r with a vector diagram [5]; (b)(i) electron kinetic energy from Coulomb force = mv2/r [5]; (b)(ii) electric potential energy [3]; (c) what if the electron radiated energy [2] |
June 2026 (10 structured questions)
| Q | Marks | Topic | Context | Parts [marks] and method |
|---|---|---|---|---|
| 11 | 3 | Electric fields | Field sensor near a charged sphere | (a) define an electric field [1]; (b) E at 45 cm, E = kQ/r2 [2] |
| 12 | 6 | Momentum | Spacecraft docking with a space station | 2D momentum conservation by components [6] |
| 13 | 7 | Particle physics | Proton–antiproton collisions | (a) baryon number and charge conservation [2]; (b)(i) identify particle X by conservation laws [3]; (b)(ii) explain a lifetime observation (relativity) [2] |
| 14 | 9 | Magnetic forces | Mass spectrometer | (a) field direction [1]; (b)(i) show r = p/BQ [2]; (b)(ii) show m/Q ≈ 2.4 × 10−7 kg C−1 (B = 40.0 mT) [3]; (b)(iii) test a suggested ion identity [3] |
| 15 | 6 | Rutherford | Alpha particles on a thin metal foil | *Observations and the conclusions drawn [6] |
| 16 | 6 | Capacitors | Door-alarm time delay | (a) define the time constant [1]; (b) sketch V_C against t [2]; (c) will R give exactly 25 s, V = V0e^(−t/RC) [3] |
| 17 | 9 | Particle physics | Photon creating a proton–antiproton pair | (a) is the photon energy above 2mc2 [5]; (b) proton speed from the 28 MeV excess [4] |
| 18 | 8 | Circular motion | Lorry on a track banked at 22° | (a) free-body diagram [2]; (b)(i) centripetal force [2]; (b)(ii) speed by resolving, tan θ = v2/rg [4] |
| 19 | 12 | Electric fields | Oil droplet between parallel plates | (a) field lines [2]; (b)(i) show E ≈ 4 × 104 V m−1, E = V/d [2]; (b)(ii) displacement: F = EQ, a = F/m, s = ½at2 [5]; (b)(iii) path beyond the plates [3] |
| 20 | 14 | Induction, circular motion | Rotating coil lighting a bulb | (a) why a current flows [2]; (b)(i) angular velocity from the graph [3]; (b)(ii) maximum current from the e.m.f. and I = V/R [6]; (c) effect of doubling the frequency on power [3] |
Unit 1–2 synoptic content
Unit 1–2 content averaged 2.2 marks a paper, usually as one step inside a Unit 4 question. Six papers had none (Jun 2021, Jan 2022, Jan 2023, Oct 2023, Jan 2025, Jan 2026); Jan 2021 had 11, mostly from a Millikan question built on Stokes’ law.
| Paper | Where | Unit 1–2 content | Marks |
|---|---|---|---|
| Jun 2026 | MCQ 3 | GeV s−1 as a unit of power | 1 |
| Oct 2025 | MCQ 4 | Scalar quantities | 1 |
| Jun 2025 | Q19(b)(iii) | Density to find a particle’s mass and weight | 2 |
| Oct 2024 | MCQ 2 | Units of a vector quantity | 1 |
| Jun 2024 | Q13(a); MCQ 1 | Friction on a tilted surface; SI base units | 4 |
| Jan 2024 | Q19(a) | Photon energy, E = hc/λ | 3 |
| Jun 2023 | Q18(b)(i) | Energy conservation, mgh = ½mv2 | 3 |
| Oct 2022 | MCQ 6 | Base units of the tesla | 1 |
| Jun 2022 | Q17(b) | Projectile range of a hammer throw | 5 |
| Oct 2021 | Q15(a)(ii) | Energy conservation up a tower | 3 |
| Jan 2021 | Q19(a) and (c); Q16(b)(i); MCQ 1 | Stokes’ law and terminal velocity; resistivity, R = ρl/A; vectors | 11 |
| Jun 2020 | Q15(a); Q18(c) | Work done, W = Fs; standing waves | 5 |
| Jan 2020 | Q13(a) | Elastic strain energy | 2 |
The de Broglie relation λ = h/p is printed in the Unit 2 section of the formula sheet but is counted here as Unit 4 content, because the Unit 4 specification uses it to explain why high energies are needed.
Prediction for October 2026
The starred 6-mark question is most likely to be electromagnetic induction, with a linac or cyclotron as the runner-up. Around it, expect the usual core: capacitor exponentials, 2D momentum, conservation laws and electric-field calculations.
| Prediction | Confidence | Evidence |
|---|---|---|
| Starred 6-marker on induction and Lenz’s law (magnet through a coil or tube, eddy-current braking, induction heating or charging, a generator) | Most likely | Most frequent starred topic (6 of 19) but not starred in the last 7 papers, since Jan 2024. Two of the five October starred questions were induction (Oct 2022, Oct 2023) |
| Starred 6-marker on a linac or cyclotron | Runner-up | Starred 5 times. Jun 2026 was the only paper of the 19 with no accelerator question at all |
| Rutherford as the starred question | Less likely | Starred in both Oct 2025 and Jun 2026. Still expect it as an MCQ (12 of 19 papers) |
| A capacitor exponential calculation plus ½CV2 | Near-certain | Exponential in 16 of 19. Capacitors took only 7 marks in Jun 2026 against an average of 10.4 |
| A 2D collision followed by an elastic check | Near-certain | 2D momentum in 16 of 19; elastic check in 11 |
| Induction explained in words, plus an e.m.f. calculation | Near-certain | Explanation in 19 of 19; calculation in 15 |
| A conservation table and a MeV/GeV ↔ kg conversion | Near-certain | Both in 19 of 19 |
| Banked or conical motion, or a vertical circle | Very likely | 9 and 8 of 19 respectively; circular motion averages 10 marks |
| Field lines plus Coulomb’s law, E = kQ/r2 or V = kQ/r, and a uniform-field E = V/d, F = EQ step | Very likely | Field lines in 12 of 19; uniform field in about 13 |
| r = p/BQ from a MeV energy; relativistic muon lifetime | Likely | About 13 and 11 of 19 |
| Derive a = v2/r (5 marks) | Possible | 5 of 19, roughly every third or fourth paper; last in Jan 2026 |
| Derive r = p/BQ (2 marks) | Possible | Jun 2023 and Jun 2026 |
| 9 to 12 structured questions, several worth 4 marks or fewer | Likely | Every paper since Oct 2023 has had 8–12, and the last two October papers with 12 had three or four short ones each |
Topic totals should land near the historical averages charted above, with induction or accelerators higher if either takes the starred question.
Limits: Pearson publishes no topic rotation, and every specification point is examinable. These predictions rank likelihood from 19 papers; they are not a basis for leaving anything out.
Appendix: legacy WPH04 papers (2019)
The June and October 2019 papers are the legacy WPH04 specification: 80 marks, with 10 MCQs and 70 marks of structured questions. Their content overlaps WPH14 almost completely, so they are useful extra practice, but they are excluded from every count above.
June 2019
| Q | Marks | Topic | Parts [marks] and method |
|---|---|---|---|
| 11 | 3 | Electric fields | E at 5.0 cm from a charged sphere’s surface, with r measured from the centre [3] |
| 12 | 6 | Particle physics | CERN sculpture: explain a statement about the structure of matter [6] |
| 13 | 9 | Particle physics | Higgs boson: (a) mass in kg [3]; (b) frequency of the decay photons [3]; (c) discuss a statement [3] |
| 14 | 10 | Momentum | Air-track gliders: (a) motion after collision for three mass ratios [3]; (b)(i) velocity after collision [4]; (b)(ii) elastic check [3] |
| 15 | 12 | Electron beams, magnetic | Fine beam tube: thermionic emission [2]; show speed ≈ 7 × 106 m s−1 [2]; derive r = p/BQ [2]; calculate B [2]; suitability of the method [2] |
| 16 | 14 | Electric fields, momentum | Shuttling ball between plates: (a)(i) sketch the field [2]; (a)(ii) why the force is constant [2]; (b)(i) show a ≈ 0.2 m s−2 [4]; (b)(ii) momentum at the plate [3]; (b)(iii) average force on impact [3] |
| 17 | 16 | Capacitors, induction | Fly-zapper racquet: (a) show the discharge is exponential [2]; (b)(i) show C ≈ 10 nF [4]; (b)(ii) safe-limit check [2]; (b)(iii) energy stored [2]; (c) why a data logger [2]; *(d) how the arrangement drives a charging current [4] |
October 2019
| Q | Marks | Topic | Parts [marks] and method |
|---|---|---|---|
| 11 | 6 | Momentum | Tennis racket force–time graph: (a) ball velocity from impulse [4]; (b) using video to find the initial velocity [2] |
| 12 | 8 | Electric fields, capacitors | Touchscreen: (a) field lines [3]; (b) energy stored [2]; (c) calculate V [3] |
| 13 | 8 | Circular motion | Steam-engine governor (conical pendulum): (a) free-body diagram [2]; (b) angle θ by resolving [6] |
| 14 | 12 | Accelerators, nuclear, electric fields | Hospital cyclotron: *(a) how it accelerates protons [6]; (b)(i) nuclear equation for the product [3]; (b)(ii) proton–oxygen repulsion, Coulomb’s law [3] |
| 15 | 11 | Particle physics, magnetic, momentum | Lambda decay tracks: (a) pion charge from curvature [2]; (b) lambda charge [1]; (c)(i) field direction [1]; (c)(ii) pion momentum from measurements, r = p/BQ [4]; (c)(iii) momentum vector diagram [3] |
| 16 | 13 | Induction | Simple generator: *(a) why ε varies between maximum and zero [4]; (b)(i) why the area under ε–t is the change in flux linkage [2]; (b)(ii) B from the graph [3]; (c) sketch the new ε [2]; (d) why the force rises with a lamp connected [2] |
| 17 | 12 | Particle physics | LHC Xi_b baryon: (a) mass over six times the proton’s [4]; (b) why high energies are needed [3]; (c) speed and comment (relativistic) [3]; (d) open communication in science [1]; (e) benefit of investing in such experiments [1] |