How is the QCE Physics EA structured?

The EA is two papers, both sat in the assessment block at the end of Unit 4. Paper 1 is multiple choice and short response, 50 marks (20 MC + 30 SR over 7 questions), 90 minutes plus 10 minutes perusal. Paper 2 is short response with data analysis, 47 marks (8 short response questions, no MC), 90 minutes plus 10 minutes perusal. Combined total 97 marks; the EA contributes 50 percent of the final subject result. The EA examines Units 3 and 4 cumulatively, so Unit 3 content remains examinable months after IA1 and IA2.

When should EA preparation begin?

Serious preparation begins eight weeks before the assessment block, typically the start of Term 4. Earlier work is content delivery in Unit 4; later work leaves no time for past-paper practice and diagnostic rework. The candidates who scale highest start the eight-week plan on the dot, even if Unit 4 content is not fully delivered yet.

How much time should each paper question take?

Paper 1 multiple choice: about 1.5 minutes per question; short response: 1.5 minutes per mark. Paper 2 extended response and data analysis: 1.5 minutes per mark, with the extended response items requiring an explicit 30-second planning step before writing. Reserve five minutes at the end of each paper for review of units, sig figs and unanswered parts.

What are the highest-yield Unit 4 topics?

Four. Special relativity (time dilation $\Delta t = \gamma \Delta t_0$, length contraction, relativistic momentum), the photoelectric effect ($E = hf - \phi$, threshold frequency, stopping voltage), the Bohr atom and atomic spectra (energy levels, transitions, photon wavelengths), and nuclear physics (mass defect, binding energy per nucleon, decay equations). Together they account for the majority of Unit 4 marks across the released EA papers.

What is the difference between short response and extended response?

Short response questions are typically 2 to 6 marks, asking for a calculation, a derivation or a focused explanation in two or three sentences. Extended response questions are 6 to 10 marks, asking for a multi-step calculation with reasoning or an explanation linking several Unit 3 or Unit 4 principles, presented as a structured paragraph or annotated calculation.

What is the formula sheet and data booklet?

QCAA provides a Senior Physics Formula and Data Book with every EA paper. It contains every formula needed and standard constants. Knowing where each formula sits in the booklet and what variable each symbol means is part of preparation; opening the booklet during the paper and hunting for a formula costs time. A photocopy of the booklet should be on your desk for every practice paper from week one of the eight-week plan.

QLDPhysics

QCE Physics External Assessment strategy: the 2026 guide to Papers 1 and 2

How to prepare for the QCE Physics External Assessment in 2026. Paper structure, the eight-week study plan, the formula sheet and data booklet, time allocation in-paper, the four highest-yield Unit 4 topics, and the common pitfalls that cost top-band candidates marks.

Generated by Claude Opus 4.818 min readQCAA-PHYS-EAUpdated 2026-05-25

Reviewed by: AI editorial process; not yet individually human-reviewed

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What this guide is for
Paper structure
The eight-week study plan
The formula sheet and data booklet
In-paper time allocation
The four highest-yield Unit 4 topics
Common pitfalls
Check your knowledge

What this guide is for

The QCE Physics External Assessment is the culminating assessment for General Physics. Two papers (Paper 1 = 50 marks, Paper 2 = 47 marks; combined 97 marks), sat in the end-of-year assessment block. Combined they are 50 percent of the subject result. The EA is cumulative across Units 3 (Gravity and electromagnetism) and 4 (Revolutions in modern physics), so Unit 3 material remains examinable months after IA1 and IA2 are over.

This guide covers paper structure, the eight-week preparation plan, the formula sheet and data booklet, in-paper time allocation, the four highest-yield Unit 4 topics, and the common pitfalls that cost top-band candidates marks.

Paper structure

Paper 1. 50 marks. 90 minutes plus 10 minutes perusal. Two sections.

Section 1 is multiple choice. 20 questions (Q1 to Q20), four options each, 1 mark each, no penalty for guessing, 20 marks total. These cover content recall, formula application and basic interpretation. Pacing target: 1.5 minutes per question.

Section 2 is short response. 7 short response questions (from Q21), 30 marks total. These require calculation, derivation or focused explanation. Pacing target: 1.5 minutes per mark.

Paper 2. 47 marks. 90 minutes plus 10 minutes perusal. Single section.

Section 1 is 8 short response questions, 47 marks (no multiple choice). Includes stimulus material (graphs, tables, apparatus diagrams) and items integrating data analysis with multi-part calculation and explanation. These reward the same data-test skills tested in IA1: extract values, identify the relevant principle, link to a claim. Pacing target: 1.5 minutes per mark plus 30 seconds of planning before writing an extended item.

The eight-week study plan

Weeks one and two: Unit 3 consolidation

Goals. Refresh Unit 3 content five to seven months after IA1 and IA2.

Tasks. Reread one Unit 3 topic per day. Work three problems per topic. By end of week two, every Unit 3 formula should be retrievable without the booklet.

Time. About 60 minutes per day.

Two velocity snapshots make decomposition visible: the horizontal arrows are the same length while the vertical components fall by 9.8 m/s every second, which is the entire content of EA projectile questions.

Two snapshots 90° apart make centripetal motion visible: the velocity rotates with the position while the inward force keeps the radial distance constant, so the speed |v| stays the same and the trajectory closes.

Weeks three and four: Unit 4 core

Goals. Master the four highest-yield Unit 4 topics: special relativity, photoelectric effect, Bohr atom, nuclear physics.

Tasks. For each topic, write a one-page summary of the named equations and the conceptual reasoning ('why is time dilation a consequence of the constancy of $c$ '). Work five calculation problems per topic.

Time. About 75 minutes per day.

Weeks five and six: timed paper practice

Goals. Sit two full EA papers under timed conditions. Self-mark against QCAA marking schemes (released with every past paper on the QCAA Senior Physics subject page).

Tasks. Paper 1 in week five, paper 2 in week six. After each, identify the lowest-scoring question type and design a 90-minute intervention before the next paper.

Time. Two timed papers per week (180 minutes plus rework) plus 30 minutes daily of targeted weak-area drills.

Week seven: integration and weak-area drills

Goals. Address the specific weak areas identified in weeks five and six.

Tasks. One more full timed paper. Targeted drills on the weakest topic.

The error log built in IA1 preparation is extended here. Every error gets one line: question type, mistake, fix.

Week eight: taper

Goals. Reduce volume, increase reliability.

Tasks. Three short sessions (30 to 45 minutes) on three different topic areas. Reread the formula sheet daily. Reread the error log nightly.

The day before each paper. Reread the error log. Light review of the formula booklet. Sleep.

The formula sheet and data booklet

QCAA provides a Senior Physics Formula and Data Book with every EA paper. Every formula required for the assessment is in this booklet, alongside fundamental constants and conversion factors.

Knowing the booklet is part of preparation. Print a copy on day one of the eight-week plan and keep it on your desk for every practice question. By week three, you should know which page contains which family of formulas without checking.

The booklet is helpful but it is not a free lookup. A candidate who has to hunt for $E = hf$ during paper one has already lost a minute. A candidate who knows it is on page two of the booklet, in the photons section, loses ten seconds.

In-paper time allocation

Paper 1. Section A about 30 minutes (1.5 minutes per question). Section B about 55 minutes (1.5 minutes per mark). Five minutes review.

Paper 2. Section A about 40 minutes including stimulus reading. Section B about 45 minutes including 30-second planning per extended response. Five minutes review.

If you fall behind. Skip and return. Multi-mark questions where the first part is unclear can have later parts attempted independently. Mark the skip with a clear circle to find on return.

If you finish early. Reread for sig figs, units, missed parts. Almost every paper has at least one missed mark recoverable on review.

The four highest-yield Unit 4 topics

Special relativity. Time dilation, length contraction, relativistic momentum, relativistic energy. The named equations are $\Delta t = \gamma \Delta t_0$ , $L = L_0/\gamma$ , $p = \gamma m v$ and $E = \gamma m c^2$ where $\gamma = 1/\sqrt{1 - v^2/c^2}$ . Conceptual reasoning. Common questions involve muon decay, GPS satellites, particle accelerators.

Photoelectric effect. The named equation is $E_k = hf - \phi$ where $\phi$ is the work function. Concepts. Threshold frequency, stopping voltage, why classical electromagnetic theory cannot explain the observations. Common stimulus types are stopping-voltage graphs and photocurrent-frequency graphs.

Bohr atom and atomic spectra. Energy level diagrams. Transitions emit photons of energy $\Delta E = hf = hc/\lambda$ . The hydrogen spectrum and the Rydberg formula are typical. Common questions involve calculating the wavelength of a specified transition or identifying which transition produces a given line.

The n = 1 to n = 2 gap is over five times the n = 2 to n = 3 gap; this real spacing is what makes the Balmer photons visible while Lyman photons are ultraviolet.

Nuclear physics. Mass defect from atomic mass and nucleon count. Binding energy from $E = mc^2$ . Binding energy per nucleon as the stability indicator. Decay equations balancing mass number and atomic number for alpha, beta-minus, beta-plus and gamma decay. Common questions ask for nuclear equation completion or stability comparisons.

Common pitfalls

Sig figs. The QCAA convention is three significant figures unless the data warrants otherwise. Two sig figs is acceptable when the data has only two; four is excessive. Every numerical answer carries explicit sig fig consideration.

Units. Every numerical answer carries explicit units. Lost-mark patterns at top band cluster around units (frequency in Hz not just s $^{-1}$ , momentum in kg m s $^{-1}$ , energy in J or eV consistently throughout a question).

Sign conventions. Vector quantities require positive-direction consistency within a question. Lenz's law sign, gravitational potential energy sign, work-energy theorem sign. Set a convention at the start and stick to it.

Extended response without planning. Six to ten-mark questions launched into without a 30-second plan typically lose two to three marks for missing structure. The 30 seconds spent listing the principles to invoke is recovered five times over in writing.

Formula booklet hunting. As above. Know the booklet.

Calculator-style answers. A numerical answer without interpretation is half a mark. Every numerical answer in a reasoning context needs a sentence: "this means that ..." or "therefore the claim is supported because ...".

Check your knowledge

Eight EA-style multi-part questions across the Unit 3 and Unit 4 subject matter, with mark allocations shown. Attempt under exam conditions (about 1 minute per mark) before checking against the solutions block. Take $g = 9.80 \ \text{m s}^{-2}$ , $c = 3.00 \times 10^{8} \ \text{m s}^{-1}$ , $h = 6.63 \times 10^{-34} \ \text{J s}$ , $e = 1.60 \times 10^{-19} \ \text{C}$ , $m_e = 9.11 \times 10^{-31} \ \text{kg}$ where required.

A projectile is launched at 25 m s $^{-1}$ at 35 degrees above the horizontal from level ground. Air resistance is negligible. (a) Calculate the maximum height. (b) Calculate the horizontal range. (c) Calculate the speed and direction of the projectile 1.50 s after launch. (8 marks)
A 1500 kg car negotiates a horizontal circular curve of radius 80 m at 20 m s $^{-1}$ . (a) Calculate the centripetal acceleration. (b) Calculate the magnitude and direction of the net horizontal force on the car. (c) Calculate the minimum coefficient of static friction between the tyres and the road that allows this turn. (5 marks)
A square loop of side 0.20 m, with 200 turns and resistance 4.0 ohms, lies in a uniform magnetic field that is initially 0.60 T directed perpendicular into the page. The field is reduced linearly to zero over 0.50 s. (a) Calculate the magnitude of the induced EMF. (b) Calculate the magnitude of the induced current. (c) State, with reference to Lenz's law, the direction of the induced current as viewed from in front of the page. (6 marks)
(a, 3) Light of wavelength 400 nm illuminates a sodium metal surface (work function 2.28 eV). Calculate the maximum kinetic energy of emitted photoelectrons in eV. (b, 2) State whether photoelectrons are emitted when the same surface is illuminated by 600 nm light, justifying with calculation. (c, 2) Explain in two sentences why this observation supports the photon model over the wave model of light. (7 marks)
A muon created 60 km above the Earth has a proper lifetime of 2.20 micro-seconds and travels at 0.999c relative to the Earth. (a) Calculate the time-dilated lifetime in the Earth's frame. (b) Calculate the distance the muon travels in the Earth's frame in this lifetime. (c) Calculate the length-contracted distance from 60 km altitude in the muon's frame, then state whether the muon reaches the surface and justify. (7 marks)
The first three Bohr energy levels of hydrogen are $E_1 = -13.6 \ \text{eV}$ , $E_2 = -3.40 \ \text{eV}$ , $E_3 = -1.51 \ \text{eV}$ . (a) Calculate the wavelength of the photon emitted when an electron transitions from $n = 3$ to $n = 2$ . (b) State the region of the electromagnetic spectrum. (c) Sketch and label an energy-level diagram showing this transition and its emitted photon. (5 marks)
$^{238}_{92}U$ decays through a series of alpha and beta-minus emissions to $^{206}_{82}Pb$ . (a) Determine the total number of alpha and beta-minus particles emitted. (b) The half-life of $^{238}U$ is $4.5 \times 10^{9}$ years. Calculate the activity of a 1.00 mg sample ( $M_r = 238.05$ , $N_A = 6.02 \times 10^{23}$ ). (c) Explain in one sentence why $^{238}U$ remains naturally abundant on Earth despite being radioactive. (6 marks)
A 50 km transmission line carries 200 MW of electrical power from the Townsville coal-fired plant to inland mining customers. The line has total resistance $4.0 \ \Omega$ . (a) Calculate the line current and the percent power loss at the operating voltage of 275 kV. (b) Calculate the percent power loss if the same line operated at 110 kV. (c) Explain in two sentences why long-distance transmission uses very high voltages despite the cost of step-up and step-down transformers. (6 marks)

Solutions

Q1: Decompose: $u_x = 25 \cos 35 = 20.5 \ \text{m s}^{-1}$ ; $u_y = 25 \sin 35 = 14.3 \ \text{m s}^{-1}$ . (a) At max height $v_y = 0$ , so $h = u_y^2 / (2g) = (14.3)^2 / 19.6 = 10.4 \ \text{m}$ . (b) Time of flight $T = 2 u_y / g = 2 \times 14.3 / 9.80 = 2.92 \ \text{s}$ . Range $R = u_x T = 20.5 \times 2.92 = 59.9 \ \text{m}$ . (c) At $t = 1.50$ s: $v_x = 20.5 \ \text{m s}^{-1}$ ; $v_y = 14.3 - 9.80 \times 1.50 = -0.40 \ \text{m s}^{-1}$ (just past apex, descending). $v = \sqrt{20.5^2 + 0.40^2} = 20.5 \ \text{m s}^{-1}$ . Angle below horizontal $= \arctan(0.40/20.5) = 1.1$ degrees. The projectile rises to 10.4 m, lands 59.9 m downrange, and at 1.50 s is moving 20.5 m s $^{-1}$ at 1.1 degrees below the horizontal.
Q2: (a) $a_c = v^2 / r = 20^2 / 80 = 5.00 \ \text{m s}^{-2}$ . (b) $F_{net} = m a_c = 1500 \times 5.00 = 7500 \ \text{N}$ directed horizontally toward the centre of the circle. (c) Friction provides this force: $\mu m g \geq F_{net}$ , so $\mu \geq F_{net} / (m g) = 7500 / (1500 \times 9.80) = 0.510$ . The minimum coefficient of static friction is 0.51.
Q3: (a) Area $A = 0.20^2 = 0.040 \ \text{m}^2$ . Flux change per turn $|\Delta \Phi| = 0.60 \times 0.040 = 0.024$ Wb. $|\varepsilon| = N |\Delta \Phi / \Delta t| = 200 \times 0.024 / 0.50 = 9.6 \ \text{V}$ . (b) $I = \varepsilon / R = 9.6 / 4.0 = 2.4 \ \text{A}$ . (c) The flux into the page is decreasing; Lenz's law says the induced current opposes this decrease by generating flux into the page, so by the right-hand rule the current flows clockwise as viewed from in front of the page.
Q4: (a) Photon energy $E_{ph} = hc/\lambda = 6.63 \times 10^{-34} \times 3.00 \times 10^{8} / (400 \times 10^{-9}) = 4.97 \times 10^{-19}$ J $= 4.97 \times 10^{-19} / 1.60 \times 10^{-19} = 3.11$ eV. $K_{max} = E_{ph} - \phi = 3.11 - 2.28 = 0.83$ eV. (b) Photon energy at 600 nm $= 1240/600 = 2.07$ eV (using $1240 \ \text{eV nm}$ ); less than $\phi = 2.28$ eV, so no photoelectrons are emitted regardless of intensity. (c) The wave model predicts that high-intensity 600 nm light should eventually deliver enough energy to eject electrons, but observation shows no emission at any intensity below threshold frequency; energy of light arrives in discrete photon packets, supporting the photon model.
Q5: (a) Lorentz factor $\gamma = 1/\sqrt{1 - 0.999^2} = 1/\sqrt{1 - 0.998} = 1/\sqrt{0.001998} = 22.4$ . Time in Earth frame $t = \gamma \tau = 22.4 \times 2.20 \times 10^{-6} = 4.92 \times 10^{-5}$ s. (b) Distance in Earth frame $d = v t = 0.999 \times 3.00 \times 10^{8} \times 4.92 \times 10^{-5} = 1.47 \times 10^{4}$ m $= 14.7$ km. (c) Length-contracted distance in muon's frame: $L = L_0/\gamma = 60\,000/22.4 = 2.68 \times 10^{3}$ m $= 2.68$ km. In its own frame, the muon traverses only 2.68 km in 2.20 micro-seconds at 0.999c (which equals 0.999 $\times$ 3.00 $\times$ 10 $^{8}$ $\times$ 2.20 $\times$ 10 $^{-6}$ = 660 m), so it does not reach the surface in its own frame's pure decay scenario; however, both frames agree on the outcome. In the Earth frame the muon survives long enough (time-dilated) to cover 14.7 km, still under 60 km, so under these idealised parameters the muon does not reach the surface. (In reality, atmospheric muons travel at varying speeds and 0.9999c muons do reach the surface; this question's data give 14.7 km of travel.) The Earth-frame calculation gives 14.7 km of penetration, less than the 60 km source altitude.
Q6: (a) $\Delta E = E_3 - E_2 = -1.51 - (-3.40) = 1.89$ eV. $\lambda = hc/\Delta E = 1240 \ \text{eV nm} / 1.89 = 656$ nm. (b) Visible (red) region of the electromagnetic spectrum; this is the H-alpha line of the Balmer series. (c) Diagram: horizontal lines at $E = -13.6, -3.40, -1.51$ eV labelled $n = 1, 2, 3$ ; downward arrow from $n = 3$ to $n = 2$ labelled "1.89 eV, 656 nm photon emitted". The emitted photon is in the visible region at 656 nm.
Q7: (a) Mass-number balance: $238 = 206 + 4a$ , so $a = 8$ alphas. Atomic-number balance: $92 = 82 + 2a - b$ , so $b = 2a - 10 = 6$ beta-minus particles. (b) Number of $^{238}U$ atoms: $N = (1.00 \times 10^{-3} / 238.05) \times 6.02 \times 10^{23} = 2.53 \times 10^{18}$ . Decay constant $\lambda = \ln 2 / T_{1/2} = 0.693 / (4.5 \times 10^{9} \times 3.156 \times 10^{7}) = 4.88 \times 10^{-18}$ s $^{-1}$ . Activity $A = \lambda N = 4.88 \times 10^{-18} \times 2.53 \times 10^{18} = 12.3$ Bq. (c) $^{238}U$ remains naturally abundant because its half-life ( $4.5 \times 10^{9}$ years) is comparable to the age of the Earth, so much of the original supply persists.
Q8: (a) $I = P/V = 2.00 \times 10^{8} / 2.75 \times 10^{5} = 727 \ \text{A}$ . Loss $P_L = I^2 R = (727)^2 \times 4.0 = 2.12 \times 10^{6}$ W $= 2.12$ MW. Percent loss $= 2.12/200 \times 100 = 1.06$ percent. (b) At 110 kV: $I = 2.00 \times 10^{8} / 1.10 \times 10^{5} = 1818 \ \text{A}$ . Loss $= 1818^2 \times 4.0 = 1.32 \times 10^{7}$ W $= 13.2$ MW. Percent loss $= 13.2/200 \times 100 = 6.6$ percent. (c) The $I^2 R$ loss scales as $1/V^2$ for a fixed transmitted power, so raising the transmission voltage from 110 kV to 275 kV reduces losses by a factor of about 6.3; the once-off cost of step-up and step-down transformers is recovered many times over by the saved power over the life of the line.