HSC Physics rewards students who can combine clear calculations with well-structured explanations. The 2025 exam included projectile and orbital motion problems, a photoelectric effect graph, and three long responses on special relativity, the Standard Model and cathode rays. NESA's marking feedback shows exactly which skills separated the better responses.
This guide breaks down the 2025 HSC Physics exam question by question. Every question is classified by module and topic using NESA's own mapping grid, so you can see exactly where the marks were. It also covers the answers, what better responses did and the areas NESA's markers said students need to improve.
Key Takeaways
- Marks were split exactly evenly across the four Year 12 modules: 25 marks each for Advanced Mechanics, Electromagnetism, The Nature of Light and From the Universe to the Atom.
- Motion in Gravitational Fields was the single biggest topic, worth 14 marks, including the 8-mark satellite explosion question (Q36).
- Three long responses (Q31, Q32 and Q33) were worth 19 marks together. Better responses linked specific experimental evidence to each idea instead of describing theory alone.
- Calculations needed full working: the formula, substitution, units and direction for vectors. Markers flagged unit prefixes (μ, n, k) and conversions as common errors.
- In explanation questions, markers wanted clear cause and effect, not just a statement of the outcome.
HSC Physics Examination Structure
| Feature | Section I | Section II |
|---|---|---|
| Question type | 20 multiple-choice questions | Short-answer and extended-response questions (Q21–36) |
| Marks | 20 marks | 80 marks |
| Suggested time | About 35 minutes | About 2 hours 25 minutes |
| Skills tested | Concepts, quick calculations, interpreting diagrams and graphs | Calculations, graphing, explanations, analysis and assessment of evidence |
The exam has 5 minutes of reading time and 3 hours of working time, and is worth 100 marks. NESA-approved calculators are allowed, and a data sheet, formulae sheet and Periodic Table are provided. The HSC exam mark makes up 50% of the final HSC mark. The other 50% comes from school-based assessment.
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Marks by Module in the 2025 Exam
Every question below is classified using the mapping grid in NESA's 2025 marking guidelines, which links each question to a module and syllabus topic.
| Module | Questions | Marks | Share of Exam |
|---|---|---|---|
| Module 5: Advanced Mechanics | MC 5, 7, 8, 13, 18; Q24, 28, 29, 36 | 25 | 25% |
| Module 6: Electromagnetism | MC 2, 6, 11, 14, 17; Q22, 23, 26, 30(c), 35 | 25 | 25% |
| Module 7: The Nature of Light | MC 1, 9, 12, 19; Q25, 30(b), 32, 34 | 25 | 25% |
| Module 8: From the Universe to the Atom | MC 3, 4, 10, 15, 16, 20; Q21, 27, 30(a), 31, 33 | 25 | 25% |
Marks by Syllabus Topic
| Topic | Module | Marks |
|---|---|---|
| Motion in Gravitational Fields | 5 | 14 |
| Electromagnetic Induction | 6 | 11 |
| Light and Special Relativity | 7 | 9 |
| Electromagnetic Spectrum | 7 | 7 |
| Quantum Mechanical Nature of the Atom | 8 | 7 |
| Deep Inside the Atom | 8 | 7 |
| Circular Motion | 5 | 6 |
| Light: Quantum Model | 7 | 6 |
| Projectile Motion | 5 | 5 |
| Properties of the Nucleus | 8 | 5 |
| The Motor Effect | 6 | 5 |
| Applications of the Motor Effect | 6 | 5 |
| Structure of the Atom | 8 | 5 |
| Charged Particles, Conductors and Electric and Magnetic Fields | 6 | 4 |
| Light: Wave Model | 7 | 3 |
| Origins of the Elements | 8 | 1 |
Source: NESA 2025 HSC Physics marking guidelines (mapping grid).
Section I: Multiple-Choice Breakdown
| Question | Module | Topic | What It Tested | Answer |
|---|---|---|---|---|
| 1 | 7 | Electromagnetic Spectrum | Maxwell's contribution | B (predicted the speed of EM waves) |
| 2 | 6 | Electromagnetic Induction | Step-up transformer turns ratio | A |
| 3 | 8 | Quantum Mechanical Nature of the Atom | Model explaining the hydrogen spectrum | B (Bohr) |
| 4 | 8 | Quantum Mechanical Nature of the Atom | Shortest de Broglie wavelength | D (proton at 0.9c) |
| 5 | 5 | Motion in Gravitational Fields | Kinetic energy in an elliptical orbit | D |
| 6 | 6 | Charged Particles in Fields | Magnetic field direction for an electron's path | A |
| 7 | 5 | Motion in Gravitational Fields | Comparing low and high orbits | B |
| 8 | 5 | Projectile Motion | Time to maximum height and landing speed | A |
| 9 | 7 | Electromagnetic Spectrum | Comparing stellar absorption spectra | A |
| 10 | 8 | Properties of the Nucleus | Smallest decay constant from a graph | A |
| 11 | 6 | Applications of the Motor Effect | Current when a motor slows | D (greater than 0.5 A) |
| 12 | 7 | Light: Wave Model | Graph of Malus' law | C |
| 13 | 5 | Circular Motion | Acceleration of a conical pendulum | C (v² / l sin θ) |
| 14 | 6 | Charged Particles in Fields | Effect of a field on a proton's kinetic energy | B |
| 15 | 8 | Origins of the Elements | Comparing stars on an H–R diagram | C |
| 16 | 8 | Properties of the Nucleus | Identifying a nucleus from a decay | A (boron-10) |
| 17 | 6 | Electromagnetic Induction | Induced emf as a loop moves away from a wire | C |
| 18 | 5 | Motion in Gravitational Fields | Launching at escape velocity | D |
| 19 | 7 | Light and Special Relativity | Mass change when energy is released | B |
| 20 | 8 | Deep Inside the Atom | Pair production in a particle accelerator | C |
Source: NESA 2025 HSC Physics marking guidelines (answer key and mapping grid). Descriptions of what each question tested are our own.
Multiple-Choice Questions to Watch
- Question 11: When a motor slows down, its back emf decreases, so the net voltage across the coil rises and the current increases above 0.5 A.
- Question 14: A proton entering an electric field perpendicular to the field feels a force along the field, which does work on it, so its kinetic energy increases. A magnetic field would change its direction but not its speed.
- Question 16: Boron-10 absorbs a neutron to become boron-11, which then emits an alpha particle (mass 4, charge 2) to leave lithium-7.
- Question 18: Escape velocity doesn't depend on direction. Launched at escape velocity with no atmosphere, the mass escapes and its speed approaches zero at an infinite distance.
- Question 19: By E = mc², releasing energy from a sealed system means its mass decreases, even though no matter leaves the jar.
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Section II: Question-by-Question Breakdown
| Question | Module | Topic | What It Tested | Marks | Key Answer |
|---|---|---|---|---|---|
| 21 | 8 | Properties of the Nucleus | Two methods to tell alpha and beta sources apart | 3 | e.g. penetration through paper; deflection in a magnetic field |
| 22 | 6 | Electromagnetic Induction | Energy transformations in transformers and lines | 4 | Heat losses in cores and wires |
| 23(a) | 6 | The Motor Effect | Torque on a wire loop | 3 | 6 × 10⁻⁴ N m |
| 23(b) | 6 | The Motor Effect | Changes to B and I that double the torque | 2 | e.g. B × 4 and I ÷ 2 |
| 24 | 5 | Motion in Gravitational Fields | Show that m_A = 3m_B | 3 | Show |
| 25(a) | 7 | Light: Quantum Model | Graphing stopping voltage vs frequency | 3 | Threshold ≈ 0.7 × 10¹⁵ Hz |
| 25(b) | 7 | Light: Quantum Model | Explaining the results with the photon model | 3 | Explanation |
| 26(a) | 6 | Electromagnetic Induction | Average emf from a 90° rotation | 2 | 0.6 V |
| 26(b) | 6 | Electromagnetic Induction | Sketching emf at double speed, reverse direction | 3 | Sketch |
| 27 | 8 | Quantum Mechanical Nature of the Atom | Schrödinger vs Rutherford and Bohr | 3 | Probability orbitals; electrons as waves |
| 28 | 5 | Projectile Motion | Minimum speed for a ramp jump | 4 | 15.6 m s⁻¹ |
| 29(a) | 5 | Circular Motion | Show v = √(rg) at the top | 2 | Show |
| 29(b) | 5 | Circular Motion | Compare speeds using energy conservation | 3 | Faster at A |
| 30(a) | 8 | Quantum Mechanical Nature of the Atom | de Broglie wavelength of electrons | 2 | 182 nm |
| 30(b) | 7 | Light: Wave Model | Fringe spacing | 2 | 9.1 cm |
| 30(c) | 6 | Charged Particles in Fields | Accelerating voltage | 2 | ≈ 4.5 × 10⁻⁵ V |
| 31 | 8 | Structure of the Atom | Assess cathode ray experiments | 5 | Extended response |
| 32 | 7 | Light and Special Relativity | Analyse time dilation, length contraction and motion | 8 | Extended response |
| 33 | 8 | Deep Inside the Atom | Analyse evidence and theory in the Standard Model | 6 | Extended response |
| 34(a) | 7 | Electromagnetic Spectrum | Speed of light from Io's orbit | 2 | 2.942 × 10⁸ m s⁻¹ |
| 34(b) | 7 | Electromagnetic Spectrum | Effect of an elliptical orbit | 3 | Explanation |
| 35 | 6 | Applications of the Motor Effect | Magnet falling through a copper pipe | 4 | Explanation |
| 36 | 5 | Motion in Gravitational Fields | Motion of two pieces after an explosion | 8 | Extended response |
Key answers are based on the sample answers in NESA's 2025 marking guidelines. Topics follow NESA's mapping grid. "Charged Particles in Fields" is short for Charged Particles, Conductors and Electric and Magnetic Fields.
What the Markers Said: Module 5 – Advanced Mechanics (25 marks)
Question 24 – Satellites with equal kinetic energy
- Better responses used the stimulus, set centripetal force equal to gravitational force, and showed every step of the algebra.
- Markers noted that some students used more formulas than needed. A direct route through Fc = Fg and Ek = ½mv² was enough.
Question 28 – Projectile motion
- Better responses started with general algebraic expressions, derived the result and substituted numbers at the end, avoiding rounding errors.
- Common errors were not resolving the velocity into components first, not using vertical displacement s = 0, mixing up sin and cos, and forgetting that vertical velocity is zero at maximum height.
Question 29 – Vertical circular motion
- In 29(a), better responses recognised that at the top of the circle with no tension, gravity alone provides the centripetal force (mg = mv²/r), then rearranged clearly.
- In 29(b), better responses used conservation of energy: as the mass rises from A to B it converts kinetic energy into gravitational potential energy, so it is faster at A. Markers noted the mass has both kinetic and potential energy at both points.
Question 36 – Satellite explosion (8 marks)
- Better responses used conservation of momentum to show that the second piece (m_b) is momentarily at rest after the explosion.
- They derived the escape velocity and showed that 2v exceeds it, so m_a escapes Earth's gravity, slowing down but never returning.
- They then described m_b falling towards Earth with increasing acceleration, using conservation of energy to explain the changing speeds.
- Markers wanted the response to focus on the subsequent motion of both pieces, supported by conservation laws and formulas.
What the Markers Said: Module 6 – Electromagnetism (25 marks)
Question 22 – Energy transformations
- Better responses answered the question directly, describing transformations in both the transformers and the transmission lines: electrical energy lost as heat through eddy currents in the iron core, magnetic hysteresis, incomplete flux linkage and resistance in the wires.
- Many students gave general descriptions of step-up and step-down transformers instead of focusing on energy transformations.
Question 23 – Torque on a loop
- In 23(a), better responses used F = BIL and τ = Fr, converted cm to m and gave the direction of the torque.
- Markers noted that the coil as a whole wasn't in the magnetic field (only the 5 cm length of wire was), so an area-based approach didn't apply.
- In 23(b), better responses quantified the change in both B and I (for example, quadrupling B and halving I) so that their product doubled.
Question 26 – AC generator
- In 26(a), better responses identified ε = −NΔΦ/Δt from the formula sheet and recognised that the average emf depends only on the starting and finishing flux.
- In 26(b), better responses showed that doubling the speed doubles the frequency and the peak emf, that reversing the direction affects the graph, and that the emf starts at its greatest magnitude from this starting position. Plotting key points first helped.
Question 30(c) – Accelerating voltage
- Better responses equated qV = ½mv² and solved for V.
- Common errors included confusing voltage and velocity, and forgetting to square the velocity or multiply by ½.
Question 35 – Magnet in a copper pipe
- Better responses structured the answer in two phases. While the magnet accelerates, the changing flux induces eddy currents that create a growing upward force on the magnet, and by Newton's third law an equal downward force on the pipe raises the reading. At terminal velocity, the upward force equals the magnet's weight, so the balance reads the full 350 g.
- Markers wanted direct links between each cause, the physics involved and the observation on the balance.
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What the Markers Said: Module 7 – The Nature of Light (25 marks)
Question 25 – Photoelectric effect
- In 25(a), better responses plotted points clearly (crosses rather than small dots), drew a ruled line of best fit and extrapolated to the x-axis to read the threshold frequency of about 0.7 × 10¹⁵ Hz.
- In 25(b), better responses explained the features with the photon model: photon energy E = hf, electrons are only emitted above the threshold frequency, and kinetic energy (and stopping voltage) increases with frequency. Markers noted the gradient is h/q.
Question 30(b) – Interference fringes
- Better responses used trigonometry or the small angle approximation with m = 1 for the first bright fringe.
- Markers flagged unit prefixes: the slit separation was given in micrometres (μm) and the wavelength in nanometres (nm).
Question 32 – Special relativity (8 marks)
- Better responses defined special relativity using Einstein's two postulates, then dealt with each consequence in turn: time dilation, length contraction and relativistic momentum.
- They supported each consequence with mathematics or a thought experiment and specific experimental evidence, such as muon decay for time dilation and length contraction, and particle accelerators for relativistic momentum.
- Markers recommended using diagrams or graphs and sequencing the answer logically.
Question 34 – Measuring the speed of light
- In 34(a), better responses doubled the orbital radius to get the diameter, converted km to m and divided by the 1000 s delay.
- In 34(b), better responses explained how an elliptical orbit changes the distance light travels across Earth's orbit, and that the calculated speed is directly proportional to that distance. Annotated diagrams helped.
What the Markers Said: Module 8 – From the Universe to the Atom (25 marks)
Question 21 – Identifying alpha and beta sources
- Better responses outlined specific methods with explicit observable outcomes, such as "paper stops alpha, but beta passes through", or deflection in opposite directions in a magnetic field. Annotated diagrams helped.
- Markers flagged vague answers like "use a detector", and references to unrelated experiments such as Rutherford scattering or Chadwick's discovery of the neutron.
Question 27 – Schrödinger's model
- Better responses compared Schrödinger's model with Rutherford's and Bohr's models separately, focusing on electron behaviour: probability-based orbitals rather than fixed orbits, and electrons as waves rather than orbiting particles.
- Markers noted students should refer to the two models separately, not a combined "Rutherford–Bohr model".
Question 30(a) – de Broglie wavelength
- Better responses substituted h, m and v into λ = h/mv and showed the calculation, rather than just quoting the given value of 182 nm.
Question 31 – Cathode ray experiments (5 marks)
- Better responses focused on cathode ray experiments, linked each result to the existence and the properties of electrons, and made an overall assessment.
- Examples include deflection by electric fields (negatively charged particles, not EM waves), Thomson's charge-to-mass ratio, and results that didn't depend on the cathode material (electrons are part of all atoms).
Question 33 – The Standard Model (6 marks)
- Better responses accurately described particle accelerator experiments, linked bosons to the forces they carry, and connected at least two ideas directly to the Standard Model.
- Markers noted that the Higgs boson is not a force carrier (gauge boson), and recommended understanding all three components of the Standard Model: quarks, leptons and bosons.
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Common Mistakes Across the 2025 Exam
- Missing working: Markers wanted the formula, substitution and units every time, with directions for vector quantities.
- Unit prefixes and conversions: μm, nm, km and cm caught many students in Q23, Q30 and Q34.
- Describing theory without evidence: In Q31, Q32 and Q33, responses needed specific experiments linked to each idea.
- Stating outcomes without causes: Explanations needed clear cause and effect, as in Q35's two phases.
- Answering a different question: General transformer descriptions in Q22, particle properties instead of methods in Q21, and initial rather than subsequent motion in Q36.
- Graphing errors: Small dots, freehand lines of best fit and misread axis scales.
How to Prepare for HSC Physics
- Know the formulae and data sheets well, including which formula fits each type of question.
- Practise deriving results algebraically before substituting numbers, especially in projectile and orbital motion questions.
- Build an evidence bank of key experiments (muon decay, cathode ray experiments, particle accelerators, photoelectric effect) and what each one shows.
- Practise structured long responses for "analyse" and "assess" questions, dealing with each part of the question in turn.
- Practise graphing skills: clear points, ruled lines of best fit, extrapolation and gradients.
- Complete full past papers under timed conditions to practise managing 3 hours of working time.
For more preparation:
- studying other sciences? See our 2025 breakdowns for HSC Chemistry and HSC Biology
- see our 2025 HSC Maths Advanced examiner report breakdown
- understand HSC performance bands
- see the HSC exam timetable 2026 for this year's exam date.
Need Help With HSC Physics?
Our HSC Physics tutors have scored highly in the subject themselves and work one-on-one with students to master calculations, write structured long responses and use experimental evidence the way markers expect.
Sources: NSW Education Standards Authority, 2025 HSC Physics examination, marking guidelines and HSC marking feedback 2025.
