What to Study in Year 2 of A-Level Physics: No Optional Topics, A Point-by-Point Look at Edexcel Units 4 and 5, Compared with Cambridge

First, a quick note: A-Level Physics has no optional topics. The A Level portion of Cambridge 9702 (Chapters 12–25) is entirely mandatory, and all six units of Edexcel IAL are also compulsory. We have already covered the content and challenges of the Cambridge A Level portion chapter by chapter in Aiming for an A* in A-Level Physics; for practical and calculation questions, see articles 185 and 196. This article fills in the gaps: a detailed breakdown of Edexcel's Year 2 Unit 4 and Unit 5, followed by a side-by-side comparison of Year 2 content across both exam boards. Some topics appear in different years depending on the board: what is taught in Year 1 for one board might be taught in Year 2 for the other. Using the wrong textbook can easily lead to missing topics or studying unnecessary material. This is based on the Pearson IAL Physics Specification (3rd edition) and Cambridge 9702 (2025–2027 syllabus).

1. The Three Units in Edexcel Year 2

• Unit 4 and Unit 5 can be taken in January, June, or October each year; question types may include multiple-choice, short-answer, open-response, calculation, and extended-response questions;
• Each unit tests Level 2+ mathematical skills for at least 36 marks;
• Unit 4 may include synoptic questions requiring knowledge from Units 1 and 2, while Unit 5 may draw on Units 1, 2, and 4;
• For the practical unit, Unit 6, see article 185.

2. Unit 4: Further Mechanics, Fields, and Particles

Further Mechanics:

• Impulse FΔt = Δp; conservation of momentum in two dimensions; determining whether collisions are elastic or inelastic; deriving and using Eₖ = p²/2m;
• Radian and degree conversions; angular velocity, v = ωr, T = 2π/ω; deriving centripetal acceleration a = v²/r = rω² using vector diagrams; centripetal force.

Electric and Magnetic Fields:

• Electric field strength E = F/Q; Coulomb's law; electric fields and potentials of point charges; E = V/d between parallel plates; describing radial and uniform fields using field lines and equipotential lines;
• Capacitance: C = Q/V; deriving stored energy W = ½QV from the area under a V–Q graph, as well as ½CV² and ½Q²/C; charging and discharging curves and time constants in RC circuits; the exponential discharge equation Q = Q₀e^(−t/RC) and corresponding current, voltage, and logarithmic equations;
• Magnetic Fields: magnetic flux density, magnetic flux, and flux linkage; F = Bqv sin θ and F = BIl sin θ, Fleming's left-hand rule; factors affecting induced EMF; Faraday's and Lenz's laws, ε = −d(Nφ)/dt.

Nuclear and Particle Physics:

• Nucleon and proton numbers; large-angle scattering of α particles and the nuclear model of the atom, and how our understanding of atomic structure has evolved over time;
• Thermionic emission, acceleration of electrons by electric and magnetic fields; the role of electric and magnetic fields in particle accelerators (linear accelerators and cyclotrons) and detectors; deriving and using r = p/BQ;
• Analyzing particle interactions using conservation of charge, energy, and momentum, and interpreting particle tracks; why high energies are needed to study nucleon structure; production and annihilation of matter and antimatter (ΔE = c²Δm); conversions between MeV, GeV and MeV/c², GeV/c² and SI units; relativistic lifetime extension (relativistic formulas are not required);
• Quark-Lepton Standard Model: classification of baryons, mesons, leptons, and photons; the model's symmetry predicting the top quark; antiparticles; determining whether reactions can occur using conservation of charge, baryon number, and lepton number; writing and interpreting particle equations.

Core practicals for Unit 4: investigating the relationship between force and change in momentum (9), using IT to analyze ball collisions (10), and analyzing capacitor charging and discharging using an oscilloscope or data logger (11).

3. Unit 5: Thermodynamics, Radiation, Oscillations, and Cosmology

Thermodynamics:

• ΔE = mcΔθ and ΔE = LΔm; internal energy as the random distribution of molecular kinetic and potential energies; absolute zero, the relationship between mean molecular kinetic energy and thermodynamic temperature; ideal gas pV = NkT; deriving and using ½m⟨c²⟩ = (3/2)kT.

Nuclear Decay:

• Binding energy, calculating mass defect using ΔE = c²Δm; atomic mass unit u; explaining fusion and fission using the specific binding energy curve; why fusion requires extremely high density and temperature;
• Background radiation and its treatment in calculations; properties, penetrating power, and ionizing ability of α, β, and γ radiation; nuclear reaction equations; the spontaneous and random nature of decay; determining half-life from graphs, A = λN, dN/dt = −λN, λ = ln2/t½, N = N₀e^(−λt) and their logarithmic forms.

Oscillations:

• Conditions for simple harmonic motion F = −kx; equations such as a = −ω²x, x = A cos ωt; periods of mass-spring systems and simple pendulums; displacement-time and velocity-time graphs; resonance; conservation of energy in damped and undamped oscillations; free and forced vibrations; qualitative effects of damping on resonance; how damping and plastic deformation of ductile materials reduce amplitude (the syllabus cites buildings in seismic zones as an application).

Astrophysics and Cosmology:

• Gravitational Fields: g = F/m; Newton's law of universal gravitation; field strength and gravitational potential of point masses; comparing electric and gravitational fields; analyzing orbital motion using Newton's laws;
• Stars: blackbody radiation and its radiation curves; Stefan-Boltzmann law L = σAT⁴; Wien's displacement law; I = L/4πd²; measuring distances using trigonometric parallax and standard candles; the Hertzsprung-Russell diagram and its relationship to stellar life cycles;
• Cosmology: Doppler effect; redshift z = Δλ/λ ≈ Δf/f ≈ v/c; Hubble's law v = H₀d; debates over the age and ultimate fate of the universe related to the value of the Hubble constant and dark matter.

Core practicals for Unit 5: calibrating a thermistor in a potential divider circuit as a thermostat (12), measuring specific latent heat of a phase change (13), investigating the relationship between gas pressure and volume at constant temperature (14), investigating the absorption of γ radiation by lead (15), and determining an unknown mass using the resonant frequency of a known mass (16).

4. Comparison of Year 2 Content Between the Two Exam Boards

The table below only lists topics that are located in different years or appear in only one board's syllabus (selected examples):

The practical takeaway is: if you switch exam boards, or use textbooks and practice questions from the other board, you must align with your own syllabus. For example, an Edexcel student using Cambridge textbooks to review Year 2 will miss particle accelerators and the HR diagram, and will unnecessarily study the Hall effect and medical physics. Cambridge students should note that the photoelectric effect is A Level content in Cambridge, while 2D momentum and quarks must be completed in Year 1.

5. How to Study Year 2 Content

Here are some practical recommendations based on experience:

1. Study electric and gravitational fields side by side: The Edexcel syllabus explicitly requires comparing the two fields, and the structure of the two chapters in Cambridge is almost identical. Create a comparison table with definitions, point source formulas, and potential expressions side by side;
2. Practice exponential decay together: Capacitor discharge and nuclear decay share the same mathematical form. Practice using logarithmic graphs to find the time constant and decay constant together;
3. Practice "conservation checks" in particle physics: Use charge, baryon number, and lepton number to check step-by-step whether a reaction can occur, and practice reading particle track diagrams;
4. Make flashcards for astrophysics: There are many concepts but few formulas. Organize them by "principle—formula—verbal explanation," focusing on the HR diagram and cosmological arguments;
5. Focus on math marks: Edexcel tests Level 2+ math for at least 36 marks per unit. Be proficient in unit conversions, logarithmic graphs, and trigonometry;
6. Review Year 1 for synoptic questions: Units 4 and 5 may test content from Year 1 units, so do not neglect Year 1 material.

Conclusion

A-Level Physics has no optional topics; the Year 2 content is fixed. Edexcel's Unit 4 and Unit 5 cover further mechanics, fields, particle physics, thermal physics, nuclear decay, oscillations, and astrophysics. The Year 2 content for both exam boards is broadly similar, but there are clear differences in the placement and inclusion of topics like the photoelectric effect, 2D momentum, particle physics, and medical physics. Go through your own syllabus point by point, and combine it with core practicals and past papers to create a clear checklist for your Year 2 revision. If you need A-Level Physics tutoring, feel free to chat with our teachers.

Verification note: This article was verified in September 2026. The duration, marks, weighting, exam sessions, question types, minimum math marks requirement, synoptic question details, topic content, and core practicals 9–16 for Edexcel Units 4, 5, and 6, as well as the inclusion of the photoelectric effect and de Broglie equation in Unit 2, are sourced from the Pearson International Advanced Level Physics Specification (3rd edition, July 2021). The chapter locations for Cambridge content are sourced from Cambridge International Physics 9702 syllabus for 2025, 2026 and 2027; the detailed requirements for Chapters 12–25 were verified in article 177 on this site. "Not in the syllabus" in the comparison table means we could not find the corresponding entry in the syllabus content list. The content is our translated excerpt. The study methods are our practical recommendations based on experience.

References:

• Pearson Edexcel: International A Level Physics Specification (PDF)
• Cambridge International: Physics 9702 Syllabus 2025–2027 (PDF)