§-Past paper

QLDPhysics2023

QCE Physics 2023

Walkthrough of the 2023 QCE physics exam: what it assessed, strategy tips, and the common errors flagged in the official marker report.

Marks: 90
Time: 180 min
Authority: QCAA
Updated: 2026-10-07

Open the official PDF Official marking notes

Key fact

This paper was set on the 2019 QCAA syllabus. From the 2026 external assessments the 2025 syllabus applies, so some content and the exam format have changed. It is still useful practice, but check the current QCAA Physics syllabus and QCAA's 2026 key changes before relying on it. The total marks at the top of this page are QCAA's published total for this year's papers (check the marking guide), and the time shown is two papers of 90 minutes working time. Marks and question types vary, so use QCAA's own paper.

What this paper assessed

The QCE Physics external assessment (Paper, worth 50% of the Unit 3 & 4 result) drew on the Unit 3 and Unit 4 content of the QCAA syllabus:

Unit 3 - Gravity and electromagnetism: projectile and circular motion, gravitational fields and orbits, electric and magnetic fields, the motor effect, and electromagnetic induction (Faraday's and Lenz's laws).
Unit 4 - Revolutions in modern physics: special relativity (time dilation, length contraction, mass-energy), quantum physics and the photoelectric effect, and the Standard Model.

Many items required students to extract data from a graph, apply a relationship, then comment on the limitations of the model. The paper rewarded structured reasoning, correct units, and naming the law being applied before describing an effect.

Structure and timing

QCAA sets the external assessment as more than one paper, and the number of marks, the sections and the question types differ from year to year. Open the official paper for the exact structure of this year; the marks and time shown at the top of this page are a guide only.

Pace by marks. Share your working time in proportion to the marks on offer, so a 6-mark item gets about three times the time of a 2-mark item. Flag any multiple choice item that runs long and return to it.
Use perusal time. Scan for the data-heavy items and the longest calculations or extended responses so you can plan them early.
Subject habits. Set out every calculation on three lines: the relationship, the substituted values with units, and the final answer with units and appropriate significant figures. For graph-based items, mark the gradient and intercept on the page before stating their physical meaning, and keep a few minutes at the end to check units, vector directions and significant figures.

Worked practice questions (exam-style)

Worked example

Question 1 (4 marks): A ball is thrown horizontally from a cliff at $15\ \text{m s}^{-1}$ and lands after 2.0 s. Calculate (a) the horizontal distance travelled and (b) the vertical velocity on impact. (Take $g = 9.8\ \text{m s}^{-2}$ .)

Resolve into independent horizontal and vertical components.

(a) Horizontal (constant velocity): $s_x = u_x t = 15 \times 2.0 = 30\ \text{m}$ .
(b) Vertical (uniform acceleration, $u_y = 0$ ):

v_y = u_y + g t = 0 + 9.8 \times 2.0 = 19.6\ \text{m s}^{-1}\ \text{(downward)}

The horizontal and vertical motions are independent; gravity acts only vertically.

Worked example

Question 2 (5 marks): A bar magnet is pushed north-pole-first into a coil connected to a galvanometer. Using Faraday's and Lenz's laws, explain the direction of the induced current and why a force opposes the magnet's motion.

Faraday's law: the changing magnetic flux through the coil, $\varepsilon = -N\dfrac{d\Phi}{dt}$ , induces an EMF and hence a current.
Lenz's law: the induced current flows so its magnetic field opposes the increase in flux - the coil's near face becomes a north pole to repel the approaching magnet.
Opposing force: this repulsion means the experimenter must do work to push the magnet in; that work is converted to electrical energy in the coil, satisfying conservation of energy.
A faster push gives a greater $\dfrac{d\Phi}{dt}$ and a larger induced current.

Worked example

Question 3 (5 marks): A muon travels at $v = 0.95c$ relative to the ground. Its proper lifetime is $2.2\ \mu\text{s}$ . Calculate the lifetime measured by a ground observer and explain the significance for muon detection at sea level.

The proper lifetime $t_0 = 2.2\ \mu\text{s}$ is measured in the muon's rest frame. Apply time dilation:

t = \frac{t_0}{\sqrt{1 - \dfrac{v^2}{c^2}}}

The Lorentz factor:

\gamma = \frac{1}{\sqrt{1 - 0.95^2}} = \frac{1}{\sqrt{1 - 0.9025}} = \frac{1}{\sqrt{0.0975}} = \frac{1}{0.312} = 3.20

So:

t = 3.20 \times 2.2 = 7.0\ \mu\text{s}\ (2\ \text{s.f.})

Significance: the dilated lifetime is long enough for muons created high in the atmosphere to reach sea-level detectors - direct experimental evidence for special relativity.

Common errors students made

Recurring errors in QCE Physics responses include:

Missing or inconsistent units in calculations and final answers.
Mixing scalar and vector quantities (e.g. speed vs velocity, distance vs displacement).
Treating projectile motion as one-dimensional rather than resolving into components.
Forgetting that induced EMF depends on the rate of change of flux, not flux itself.

Add these subject-specific traps:

In Lenz's-law items, stating a direction without linking it to opposing the flux change and to energy conservation.
Confusing proper time and dilated time in relativity problems.
Reporting answers to too many significant figures, or dropping a negative sign/direction in field problems.
Misreading the QCAA cognition verb - describing where "analyse" or "evaluate" is required.

How to use this paper

The 2023 sitting was two papers of 90 minutes working time each, with 10 minutes of perusal in the booklets. QCAA's 2026 timetable has two papers, each with 5 minutes of perusal and 90 minutes of working time (check the current QCAA syllabus for your sitting). Sit one paper at a time under timed conditions, pacing each by marks. Use the formula and data sheet. Mark against the QCAA marking guide and published assessment report (linked at the top of this page), which show where method and reasoning marks sit. Rebuild every calculation that lost a method mark from a clean start, listing formula, substitution and unit-checked answer on separate lines. Keep an error log mapping each lost mark to a syllabus subject-matter point, and re-attempt graph-interpretation items under time pressure after a 48-hour gap.

What this paper assessed

Structure and timing

Worked practice questions (exam-style)

Question 1 (4 marks): A ball is thrown horizontally from a cliff at 15 m s−115\ \text{m s}^{-1}15 m s−1 and lands after 2.0 s. Calculate (a) the horizontal distance travelled and (b) the vertical velocity on impact. (Take g=9.8 m s−2g = 9.8\ \text{m s}^{-2}g=9.8 m s−2.)

Question 2 (5 marks): A bar magnet is pushed north-pole-first into a coil connected to a galvanometer. Using Faraday's and Lenz's laws, explain the direction of the induced current and why a force opposes the magnet's motion.

Question 3 (5 marks): A muon travels at v=0.95cv = 0.95cv=0.95c relative to the ground. Its proper lifetime is 2.2 μs2.2\ \mu\text{s}2.2 μs. Calculate the lifetime measured by a ground observer and explain the significance for muon detection at sea level.

Common errors students made

How to use this paper

Keep going

Question 1 (4 marks): A ball is thrown horizontally from a cliff at $15\ \text{m s}^{-1}$ and lands after 2.0 s. Calculate (a) the horizontal distance travelled and (b) the vertical velocity on impact. (Take $g = 9.8\ \text{m s}^{-2}$ .)

Question 3 (5 marks): A muon travels at $v = 0.95c$ relative to the ground. Its proper lifetime is $2.2\ \mu\text{s}$ . Calculate the lifetime measured by a ground observer and explain the significance for muon detection at sea level.