Exam guide

1. Syllabus, topic list and paper structure

1a. Which syllabus

• First examined in 2022. These papers belong to the 9702 syllabus published as the 2022–2024 version, then the 2025–2027 version.
• Topic numbering: 1–11 are AS Level and 12–25 are A Level.
• The current syllabus is not in the local folder. The changes below are inferred from the papers.

Evidence of the 2022 revision in the papers

• Astronomy & cosmology (25) is examined in 8 of 9 Paper 42s:
  • Hubble's law, redshift, standard candles, and Wien's and Stefan's laws;
  • it was absent only in 2025-MJ.
• Particle physics (11) at AS (quarks, leptons, hadrons, β± decay with (anti)neutrinos) is in every P1 and every P2.
• Uniform electric fields never appear in P1/P2. In P4 they appear as A Level topic 18 (2023-ON, 2025-MJ).
• No electronics (op-amps) or communication (modulation) content appears in any paper from 2022 to 2026. The keyword search found zero hits.

From 2022–24 to 2025–26, no content change is visible:

• The Data and Formulae sheets on P2 and P4 are identical from 2022-MJ to 2026-MJ. P4 has 25 formulae, from uniformly accelerated motion to Doppler redshift.
• The same topic set appears.
• Question shapes are unchanged.

The visible change is administrative (§1c): a fourth time-zone variant, plus two extra Paper 3 codes.

1b. Topics and subtopics used for tagging

1c. Components, from the cover pages

The cover pages are identical from 2022 to 2026: same durations, same mark totals, all questions compulsory.

*Weights are inferred from the grade-threshold files.

• AS is weighted to 130 marks: P1 40 + P2 60 + P3 × 0.75.
• Full A Level is weighted to 260 marks: P1 + P2 + 0.75 × P3 + ≈0.94 × P4 + ≈1.21 × P5.
• Check (2026-MJ, route 12-22-33-42-52):
  • A Level: the component A thresholds give 30 + 40 + 0.75 × 33 + 0.936 × 62 + 1.213 × 20 = 177.1, which matches the published A of 177.
  • AS: 30 + 40 + 24.75 = 94.75, which matches the published A of 95.

Paper 3 sessions and variants

• Variants 31–35 (May/June) and 31, 33–36 (Oct/Nov) are different laboratory sessions with different experiments.
• Paper 3 is titled "Advanced Practical Skills 1" for 31/33/35/37 and "…2" for the others.

New from 2025: a fourth variant (x4) of every written paper, plus Paper 3 codes 37 and 38

• The x4 papers are new papers, not copies. Text similarity with variants 1–3 is only 0.23–0.59, which is front-page boilerplate level. Cover, duration and marks are the same.
• 37 and 38 reuse an existing practical from the same session:
  • in May/June 2025 and 2026, 37 = 33 and 38 = 34 (similarity 0.98–0.99);
  • in Oct/Nov 2025, 37 = 35 and 38 = 36 (same experiments).
• The option codes show how they combine:
  • From 2022–24 the codes had a first letter for the practical slot (A = 33-type, H = 34-type) and a second letter for the written variant (X = 1, Y = 2, Z = 3).
  • From 2025 a second letter C = variant 4 appears: options AC (14, 24, 37, 44, 54) and HC (14, 24, 38, 44, 54), plus AS options SA (14, 24, 37) and SB (14, 24, 38).
• Inference: variant 4 is a new administrative or time-zone variant with its own written papers. Its candidates do the same practical as a 33/34 (or 35/36) centre, under a separate code.
• Its thresholds differ:
  • 2025-MJ: lower than variant 2 (AS A 92 vs 97);
  • 2025-ON and 2026-MJ: higher (AS A 100 vs 98, and 104 vs 95).
• Mixed options (e.g. 2W = 12, 22, 33, 41, 52) also appear in 2025-MJ.

2. Topic weights per component (marks; variant 2)

2a. Paper 1 (MCQ, 40 marks × 9 = 360)

P1 is almost a fixed template.

• Every topic gets 2–6 items in every session.
• Items run in syllabus order: Q1–4 cover units and uncertainty, Q38–40 particle physics.
• Typical paper:

• Items appearing in all nine sessions:
  • a Doppler-effect item;
  • a diffraction-grating item;
  • a drag or terminal-velocity item;
  • a Kirchhoff item (often "which quantity is conserved");
  • an errors and uncertainty item;
  • a couple or moment item.
• Recycled items:
  • 2026-MJ Q12, Q31 and Q36 are near-identical to 2022-MJ Q7 (Newton's third-law pairs), Q31 (Hall-type metal block, I = Anvq) and Q36 (Kirchhoff conservation).
  • 2025-ON Q17 and Q36 repeat 2022-MJ Q18 (deriving KE) and Q37 (potentiometer).
  • Old P1 papers are worth doing in full.

2b. Paper 2 (AS structured, 60 marks × 9 = 540)

The usual P2 running order:

1. A units, uncertainty or vector opener of 7–11 marks, often merged with mechanics.
2. Two or three mechanics questions: kinematics, dynamics, forces and energy, often in one context such as a balloon, skydiver, spring launcher or sphere in a river.
3. A materials or energy question.
4. A waves or superposition question.
5. A D.C. circuits question.
6. Always last: a particle-physics question of 3–9 marks.

Combined AS weight (P1 + P2 = 900 marks):

2c. Paper 4 (A Level structured, 100 marks × 9 = 900)

P4 has a fixed 10-question skeleton, with only small swaps:

• Fields (gravitational, electric and magnetic together): 219 marks, 24% of P4.
• AS content is not examined as stand-alone parts in P4. It is used inside A Level questions, e.g. I = nAvq in 2023-ON Q4 and momentum in the force-on-wall derivation in 2026-MJ Q4.

2d. Paper 5 (30 marks × 9 = 270)

P5 is the most predictable paper in the qualification. Q2 has had the same part structure in every session:

1. (a) the gradient (and intercept) expression;
2. (b) table values with absolute uncertainties, often in log or reciprocal form;
3. (c)(i)–(iv) plot with error bars, draw best and worst lines, then find the gradient and intercept with uncertainties;
4. (d) the constants with uncertainties;
5. (e) or (f) a prediction.

Only one variation: 2022-ON and 2026-MJ swap the intercept for "mean of repeated readings ± half the range".

2e. Paper 3 (variant 33; 40 marks)

3. Bankers (examined in every session, or nearly every session)

AS (P1 + P2)

• Momentum & collisions: 9/9 sessions in both P1 and P2, 60 marks in all.
  • Conservation in 1D and 2D (components);
  • elastic vs inelastic using KE;
  • impulse = change of momentum, with average force.
• Work–energy: 9/9 in both, 64 marks.
  • KE ↔ GPE ↔ work against friction;
  • "use the concept of work to show EK = ½mv²";
  • power and efficiency.
• Moments & equilibrium: P1 9/9, P2 8/9.
  • Principle of moments with a hinged beam, wire and angle;
  • centre-of-gravity definition;
  • couples;
  • vector triangle of forces.
• Hooke's law & strain energy: 9/9 in both.
  • Spring constant from a graph;
  • EPE = ½kx² or the area under the graph;
  • springs in series or parallel.
• Kirchhoff, series and parallel circuits: 9/9 in P1, 8/9 in P2.
  • Potential dividers with a thermistor, LDR or potentiometer: 25 P2 marks in 5 sessions.
  • Qualitative "state and explain the effect" parts are almost guaranteed.
• Particle physics: every P1 (3–4 items) and every P2.
  • Quark compositions and charges;
  • meson vs baryon;
  • β± decay equations with (anti)neutrino;
  • α/β changes to proton and nucleon numbers.
• Superposition: every P1 has 4–5 items, every P2 has a question of 3–11 marks.
  • Stationary waves in tubes or strings (λ from node spacing, closed-tube λ_max = 4L);
  • double slit (λ = ax/D);
  • diffraction grating (d sin θ = nλ, maximum order);
  • coherence.
• Uncertainties: P1 9/9; P2 6/9, plus SI base units of a derived quantity in 7/9.
  • Combining % uncertainties (powers);
  • stating a value ± its absolute uncertainty to the right s.f.

A Level (P4)

• SHM: 9/9 sessions, 71 marks.
  • ω from a graph;
  • v = ±ω√(x₀² − x²);
  • E = ½mω²x₀²;
  • a–x and KE–x sketches;
  • writing x = x₀ sin ωt.
• First law and internal energy: 9/9, 59 marks.
  • Signs of work on or by a gas;
  • internal energy of a stretched wire or evaporating water;
  • p–V cycles.
• Ideal gases: 9/9, 74 marks.
  • pV = nRT / NkT;
  • c_rms;
  • assumptions of kinetic theory;
  • derivations: ⟨EK⟩ = (3/2)kT, and pV = ⅓Nm⟨c²⟩ from one particle in a box (2026-MJ).
• Capacitance: 9/9, 76 marks. Energy ½QV, capacitors in series or parallel, discharge and time constant, charge sharing.
• Quantum physics: 9/9, 71 marks.
  • Photoelectric effect;
  • de Broglie wavelength (λ = h/p, p = √(2mqV));
  • energy-level transitions;
  • "evidence for wave and particle nature" tables.
• Electric fields: 8/9 (missing 2023-MJ).
  • Coulomb's law;
  • potential of a sphere, V = Q/4πε₀r;
  • field-line drawing;
  • the isolated sphere as a capacitor (2025-ON, 2026-MJ).
• Circular motion: 8/9.
  • Radian definition: 3 sessions;
  • ω, centripetal acceleration;
  • "which forces provide the centripetal force".
• Gravitational fields: 8/9.
  • Newton's law of gravitation statement;
  • φ = −GM/r and PE = −GMm/r;
  • escape speed;
  • orbits, T² ∝ r³ derivation, geostationary orbits.
• Nuclear physics: 8/9.
  • Mass defect and binding energy per nucleon with the BE/A curve;
  • fission vs fusion;
  • decay constant and half-life.
• Magnetic fields: 8/9, the highest-weighted P4 topic.
  • Force on a conductor;
  • Hall effect and Hall probe;
  • Faraday and Lenz laws (definitions in 4 sessions);
  • flux-linkage graphs.
• Definitions asked most often (P2 + P4):

P5

• Every Q2 needs the full chain: logarithmic or reciprocal processing, error bars, a worst acceptable line, gradient and intercept uncertainty, constants with units, and a prediction.
• Q1 is always a 15-mark plan built on a given relationship ("It is suggested that…"). The answer must cover:
  • which graph to plot;
  • how each quantity is measured;
  • control variables;
  • the analysis (constants from the gradient or intercept);
  • safety;
  • extra detail.

4. Rarely tested, and trends

Rarely tested in this sample (variant 2)

Trends from 2022 to 2026

• P2 has fewer, bigger questions:
  • 7–8 questions up to 2024-MJ, then 6 in three of the last four sessions;
  • mark-weighted calculations stay around 55–60%.
• P2 Kinematics comes and goes:
  • 10 marks in 2022-MJ, 8 in 2023-ON and 9 in 2026-MJ;
  • none in either 2025 session, where energy and momentum took its place;
  • it is always one P1 block.
• P2 polarisation (Malus's law) was in 3 consecutive sessions (2022-ON to 2023-ON) and has not been seen since. Interference came back in 2025-ON and 2026-MJ.
• P4 electromagnetic induction is missing from the last three variant-2 papers (2025-MJ, 2025-ON, 2026-MJ). In 2022–24 it was 7–14 marks in every session.
  • Magnetism in those papers shifted to Hall-probe and force-on-charge work (2026-MJ) or field-line pictures (2025-MJ).
  • Faraday and Lenz still appear in other 2025 variants, so this is a sampling gap, not a syllabus change.
  • Expect induction to return.
• P4 a.c. and rectification are on the rise:
  • 0–5 marks per session from 2022-MJ to 2024-MJ, apart from 10 in 2023-MJ;
  • 7–10 marks in each session since 2024-ON.
• P4 capacitance has dipped: 2 and 5 marks in 2025-ON and 2026-MJ, after 9–11 in each of the seven sessions before. Electric fields took the slot, and the two are combined in one question (isolated-sphere capacitance).
• P4 thermal physics has grown:
  • Temperature questions (thermal equilibrium, specific heat or latent heat via the first law) give 5–9 marks in each session since 2024-ON, up from 0–3 before.
  • A recurring pattern: work done by a gas expanding at atmospheric pressure, then ΔU = Q + W, then c or L.
• P4 Q10 rotates through nuclear, medical and astronomy:
  • medical physics is absent in 2024-ON and 2026-MJ;
  • astronomy is absent in 2025-MJ.
  • Prepare all three.
• P5 contexts lean towards electricity and fields (§5).
• Thresholds were low in 2022, then normal from 2023:
  • the 2022 thresholds were very low (A Level A* 187–190);
  • 2023–24 were the highest (A* up to 215 in 2024-ON);
  • 2025–26 settled at about 201–203 (§8).

5. Practical papers: experiment types

P5 contexts (variant 2)

Planning contexts: 7 of 9 are electrical or electromagnetic (magnetism, induction, capacitors, heating). Expect a circuit diagram to be needed.

P3 variant 33 (tagged)

The structure is identical in all three:

• Q1: a few raw readings, then a six- (or five-) row results table worth 7–9 marks. Then a graph, gradient and intercept, and constants with units.
• Q2:
  1. measure a few quantities;
  2. estimate one percentage uncertainty;
  3. justify the s.f.;
  4. repeat with a second setting;
  5. calculate two k values;
  6. test them against a stated % criterion;
  7. give 4 limitations and 4 improvements (8 marks).

All 97 Paper 3 questions, 2022–2026 (every variant, classified from the opening sentence; approximate)

6. Question styles (P2 and P4, by command word, marks)

P2: a calculation paper with short "state and explain" endings

• Opening part: typically a definition or SI base-unit derivation worth 1–2 marks.
• Middle parts: 2–3-mark calculations.
• A qualitative circuit part: "state and explain the effect on the p.d. / current".
• Sketch graphs: v–t, momentum–t, KE–x, stationary-wave shape. These rose from 3 marks in 2022-MJ to 8 in 2026-MJ.

P4 is much more verbal and graphical

• About 14% definitions.
• About 16% sketches (13–21 marks per paper), with recurring shapes:

• About 12% "show that" or symbolic derivations. Examples:
  • T² ∝ r³ for an orbit;
  • ⟨EK⟩ = (3/2)kT;
  • pV = ⅓Nm⟨c²⟩ from momentum change;
  • C_T for series or parallel capacitors;
  • charge sharing;
  • escape speed v = √(−2φ);
  • p = √(2mqV).
• Graph and data analysis is embedded in P4:
  • using gradients (ln V vs t for the time constant, g vs F to find the Sun's radius);
  • "state three conclusions from Figs X and Y" in 2024-ON, 2025-MJ, 2025-ON and 2026-MJ;
  • "give units with your answer", which is credited separately.
• "State three conclusions" is a new style since 2024-ON: open-ended data interpretation (kinetic-theory graphs, rectifier traces, photoelectric results).

7. Common mistakes (examiner reports for 2022-MJ, 2022-ON and 2023-MJ; variants 12, 22, 42, 52, 33)

Paper 1 (MCQ)

• Hardest items: potentiometer polarity and null-point items. Under a quarter correct in 2022-MJ, and also hard in 2022-ON and 2023-MJ.
• Vectors and velocity:
  • adding velocity vectors instead of subtracting to find a change in velocity;
  • giving average speed for a curved path when average velocity was asked.
• Malus's law through two filters: students used the angle measured from the original plane instead of the angle between the filters.
• Waves:
  • thinking a floating object moves along with a wave;
  • not knowing that minimum pressure in a sound wave is at a rarefaction;
  • covering one slit halves the amplitude, so the intensity falls to a quarter, not a half.
• Gratings: using sin⁻¹ where tan⁻¹ is needed for screen geometry, and picking the wrong order n.
• Resistance: a stretched wire keeps its volume, so R ∝ 1/A². Strands in parallel add their areas.
• Power: at constant power, F ∝ 1/v.
• Elastic limit vs limit of proportionality: these were treated as the same.
• Advice: read "NOT correct" stems carefully, and work out the answer before looking at the options.

Paper 2 (AS structured)

Uncertainties

• Not doubling the % uncertainty for a squared quantity (or not multiplying by 4 for R⁴), or not dividing by 3 for a cube root.
• Mixing up % and absolute uncertainty.
• Quoting the value to more decimal places than its uncertainty.

Components and trigonometry

• Using the wrong trig function for a vertical component of a wire tension, or for the momentum components in a 2D collision.
• Conserving velocity instead of momentum.
• Finding KE from one velocity component only.

Motion graphs and free fall

• Curved lines where acceleration is constant.
• Final speed drawn equal to initial speed when the ball lands lower than it started.
• The line not drawn across the full time range.
• Believing heavier objects accelerate or land faster.
• Using g = 10 instead of 9.81.
• Forgetting the square root after finding t².

Definitions

• Force must be defined as the rate of change of momentum, not "ma".
• Work done needs "distance moved in the direction of the force".
• P.d. is energy transferred per unit charge.
• Coherence means a constant phase difference.
• Conservation of momentum needs "closed system".

Materials

• Doubling the extension was taken to double the EPE (it quadruples).
• Tripling the radius was taken to cut stress by 3 (it cuts it by 9).
• Using total length instead of extension, or leaving it in cm.

Waves

• Path difference for the second dark fringe is 1.5λ.
• Taking x in λ = ax/D as the bright-to-dark distance, which doubles the answer.
• Saying "dark fringes get darker" when intensity rises, and not saying the fringe separation is unchanged.
• Drawing a stationary wave as a travelling wave.
• Not knowing the closed-tube λ_max = 4L.
• Using cos θ instead of cos²θ in Malus's law.

Circuits

• Using P = V²/R without noticing that the current is the same for both resistors.
• Saying "resistance" without saying which resistance.
• Saying a filament lamp's resistance rises as its current falls.
• Confusing number density with total number of electrons.

Particle physics

• Thinking a baryon needs three identical quarks.
• Writing u→d instead of d→u for β⁻ decay.
• Naming a neutrino where an antineutrino is emitted.
• Describing an atom without its electrons.

Paper 4 (A Level structured)

Fields

• Defining potential as an energy rather than energy per unit mass or charge.
• Using the planet radius instead of the orbit radius.
• Calling centripetal force one of the forces acting, rather than the resultant.
• Writing 4πε₀ where 1/4πε₀ is meant, and dropping the sign of a charge.
• Using r instead of the separation (2 × orbit radius) for two orbiting charges.

Gases and thermodynamics

• Mixing up n and N.
• Not converting °C to K.
• Dividing c_rms by √2 a second time.
• Wrong sign for work done on vs by the gas.
• Confusing heat transferred with internal energy.
• Thinking Q and W are both zero over a cycle.
• Dropping "per unit mass" or "at constant temperature" from the latent-heat definition.

SHM

• Reading ω wrongly from an equation, or taking T as half a cycle.
• Not squaring the amplitude in E = ½mω²x₀², or leaving it in cm.
• Drawing a–x as a loop instead of a straight line with negative gradient that stops at ±x₀.
• Treating phase difference as a time.

Capacitance

• Quoting the parallel-combination formula as the definition of capacitance.
• Not inverting 1/C_T.
• Calling exponential decay "inverse" (it is rate ∝ amount remaining).
• In charge sharing, writing about energy instead of charge conservation.

Magnetism and induction

• Vague definition of B (missing "perpendicular", "per unit current per unit length").
• Wrong field directions inside and outside a solenoid.
• Reciting Lenz's law instead of applying it (the opposition is a force on the moving conductor).
• Wrong phase of an induced e.m.f. relative to the current.
• Not knowing that flux is measured in Wb.

A.c.

• Sketches with no rectification.
• P–t drawn the same shape as V–t; it should be sin², never negative.

Quantum, nuclear and astronomy

• Positive values for energy levels.
• Mixing up transitions and spectral lines.
• Setting the X-ray tube p.d. equal to hc/λ (it is eV = hc/λ).
• Defining mass defect as an energy.
• Decay definitions that reuse the word "decay".
• Annihilation answers that do not say all of the mass becomes γ energy.
• Using de Broglie's relation for a photon.
• "This galaxy is receding" confused with "the Universe is expanding".
• Pulling in Stefan–Boltzmann just because "luminosity" appears.

General

• Answers memorised from old mark schemes that do not answer the question set.
• Not giving 3 s.f. when the data has 3.
• Many blank parts (2022-ON, 2023-MJ).

Paper 5

Planning

• Control variables not named precisely (e.g. "keep the magnetic field constant" without naming B).
• Circuits that would not work: ammeter in the wrong place, d.c. symbol where a.c. is needed, oscilloscope in series.
• Vague measurement methods ("use a ruler or micrometer", a stopwatch with no stated timing method).
• Plotting the wrong axes, and claiming the line must pass through the origin.
• Not writing the constant in terms of the gradient or intercept.
• Generic safety points.

Analysis

• Log values not given to the right decimal places, or using ln for lg, or dropping 10ⁿ scaling factors.
• Error bars drawn unevenly.
• Best-fit lines forced through end points.
• Gradient taken from table points, or inverted.
• Intercept read at a false origin.
• Intercept uncertainty found by adding fractional uncertainties instead of using the worst line.
• Dropping the negative sign of an intercept, or missing powers of ten in units.

Paper 3

• Range of readings too small.
• Column headings without "quantity / unit".
• Raw lengths not to the nearest mm.
• Calculated values not matched to the s.f. of the raw data, and mixing up decimal places with s.f.
• Awkward or non-linear graph scales, and gradient triangles that are too small.
• Calculator left in radians.
• Not dividing 10T by 10.
• Unrealistic uncertainty estimates.
• Not applying the stated % criterion in the k-test.
• Vague limitations or improvements (credit needs the quantity affected and a reason). "Repeat readings" and "view at eye level" are not credited.

8. Grade thresholds (variant-2 options)

Component thresholds, A / E (raw)

Overall thresholds (weighted marks)

Reading the thresholds

• As percentages:
  • an AS A needs about 73–76% of the weighted marks (2023 onwards);
  • an A Level A needs about 68–73%;
  • A* needs about 77–83%.
• 2022 was much lower, the first post-pandemic year of the new syllabus. A* was about 72%.
• P4 is the hardest component: an A needs only 54–70 out of 100.
• P2 is next: an A needs 37–46 out of 60.
• P1, P3 and P5 need relatively high raw scores for an A: P1 about 30 out of 40, P3 about 32 out of 40, P5 about 21 out of 30.
• Variant 4 (AC / SA) thresholds:

9. Revision priorities

AS (P1 + P2)

1. Mechanics block: dynamics, momentum, forces/moments and work–energy. About 43% of AS marks. Practise multi-step contexts (balloons, launchers, beams on hinges) that chain upthrust → resultant force → kinematics → energy. Master components with the right trig function.
2. D.C. circuits and electricity: 19% of AS marks.
   • Kirchhoff and parallel combinations;
   • potential dividers with a thermistor, LDR or potentiometer;
   • e.m.f. and internal resistance;
   • drift speed I = nAvq with symbols;
   • qualitative "state and explain" answers that name each current and resistance.
3. Superposition and waves: 18%.
   • Stationary waves in tubes (open and closed), node spacing;
   • λ = ax/D with path difference in λ;
   • d sin θ = nλ and the maximum order;
   • Malus's law (cos²);
   • Doppler formula;
   • EM spectrum wavelengths.
4. Particle physics: 9%, the last question in every P2.
   • Quark charges and compositions;
   • lepton, hadron, baryon and meson classes;
   • β± equations with the right (anti)neutrino;
   • α/β bookkeeping for decay series.
5. Units and uncertainties:
   • SI base units of derived quantities (power, pressure, η, k);
   • % uncertainty with powers;
   • value ± absolute uncertainty to matching decimal places.
6. Definitions list (every session has 1–3 marks of these): work, power, pressure, moment, centre of gravity, Young modulus, elastic deformation, p.d., Kirchhoff's laws, momentum and its conservation, progressive wave, diffraction, coherence, fundamental particle.

A Level (P4)

1. Fields (gravitational, electric, magnetic): about a quarter of P4.
   • Learn the definitions word for word: field strength, potential at a point, B, Coulomb's and Newton's laws, Faraday and Lenz.
   • Use the analogous formulae and orbit derivations.
   • Draw field lines (planet, isolated sphere, solenoid).
   • Practise Hall voltage.
   • Revise induction anyway: it was absent from the last three variant-2 papers but is still examined in other variants.
2. Thermal physics (Q2–Q4, about 19%):
   • pV = nRT / NkT;
   • kinetic theory assumptions and the pV = ⅓Nm⟨c²⟩ derivation;
   • ⟨EK⟩ = (3/2)kT and c_rms;
   • first-law sign conventions with W = pΔV;
   • c and L definitions;
   • thermal equilibrium and gas thermometers.
3. SHM (every paper):
   • ω, x₀ and energy from graphs or equations;
   • a–x, v–x and KE–x sketches;
   • writing x(t);
   • damping and resonance definitions.
4. Capacitance: combinations (derive them), ½QV, the area under V–Q, the time constant from ln graphs, the isolated sphere C = 4πε₀R.
5. Quantum physics and nuclear physics (about 16% together):
   • photoelectric equation and graph;
   • de Broglie with p = √(2mqV);
   • energy-level transitions;
   • binding energy per nucleon (the curve and fission/fusion energy release);
   • λ = ln2 / t½;
   • activity calculations.
6. A.c.: r.m.s. from V = V₀ sin ωt, P–t sketches (mean = ½P₀), half-wave, full-wave and bridge rectification, smoothing by a capacitor.
7. Rotate Q10 topics:
   • X-ray attenuation, contrast and CT;
   • acoustic impedance and the reflection coefficient;
   • PET (annihilation γ energy and wavelength);
   • standard candles, Wien and Stefan for stellar radius, Hubble's law and redshift.

Practical (P3 and P5)

• P5 Q2: the routine is fixed, so drill it until it is automatic:
  • logs to the right decimal places;
  • half-range uncertainties;
  • error bars;
  • a worst line through the error-bar extremes;
  • gradient uncertainty as the difference from the worst line;
  • constants with units;
  • a prediction.
• P5 Q1: prepare plans for electrical and electromagnetic set-ups (coils, capacitors, magnets, heating wires).
  • Always state which graph to plot.
  • Give constants from the gradient or intercept.
  • Name the control variables.
  • Draw a working circuit.
  • Give specific safety points.
• P3:
  • Tables with quantity/unit headings and consistent s.f.
  • Wide ranges.
  • Graph scales that fill more than half the grid.
  • Big gradient triangles.
  • The two-values-of-k test against the stated %.
  • Limitations and improvements are 8 of 40 marks. Prepare a bank of specific ones for pendulums, balances, rulers and timing (e.g. "use a fiducial marker", "use a video with a timer", "use a set-square to check vertical").