§-Past paper

QLDPhysics2022

QCE Physics 2022

Walkthrough of the 2022 QCE physics exam: what it assessed, strategy tips, and the common errors flagged in the official marker report.

Marks: 60
Time: 120 min
Authority: QCAA
Updated: 2026-05-29

Open the official PDF ->Official marking notes

What this paper assessed

The QCAA Physics external assessment (worth 50% of the subject) covers Units 3 and 4. The 2022 paper assessed:

Unit 3 - Gravity and electromagnetism: gravitational fields and orbital motion, projectile motion, electric fields and charged particles, and magnetic fields and the motor effect.
Unit 4 - Revolutions in modern physics: special relativity, the quantum nature of light (the photoelectric effect), the standard model of particle physics, and the structure of the atom/nucleus.

Many items required students to extract data from a graph, apply a relationship, and then comment on the limitations of the model or assumptions. The extended response rewarded structured reasoning - naming the relevant law and applying it step by step - over volume of writing.

Structure and timing

60 marks in 120 minutes (about 2 min/mark), with perusal time, a QCAA formula and data sheet, and a calculator:

Section 1 - Multiple choice: about 20 marks. Budget ~30 minutes (~1.5 min each).
Section 2 - Short and extended response: about 40 marks. Budget ~85 minutes, leaving ~5 minutes to check.

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.

Worked practice questions (exam-style)

Worked example

Question 1 (5 marks): Projectile motion

A projectile is launched horizontally at $15\ \text{m s}^{-1}$ from a cliff $20\ \text{m}$ high. Taking $g = 9.8\ \text{m s}^{-2}$ and ignoring air resistance, find the time of flight and the horizontal distance travelled.

Solution. Treat horizontal and vertical motion independently. Vertically, initial vertical velocity is $0$ ; using $s = \tfrac{1}{2}gt^2$ :

20 = \tfrac{1}{2}(9.8)t^2 \implies t^2 = \frac{40}{9.8} = 4.08 \implies t = 2.02\ \text{s}

(2 marks.) Horizontally there is no acceleration, so

x = u_x \, t = 15 \times 2.02 = 30.3\ \text{m}

(2 marks.) Final answers with units (1 mark). The key principle: horizontal and vertical components are independent, and the time of flight is set by the vertical drop alone.

Worked example

Question 2 (6 marks): Electromagnetic induction

A coil of $N$ turns experiences a uniform magnetic flux that decreases from $0.040\ \text{Wb}$ to $0.010\ \text{Wb}$ in $0.050\ \text{s}$ . For $N = 250$ , calculate the average induced EMF, and explain why no EMF is induced once the flux becomes steady.

Solution. By Faraday's law the magnitude of the average induced EMF is

|\varepsilon| = N\left|\frac{\Delta\Phi}{\Delta t}\right| = 250 \times \frac{|0.010 - 0.040|}{0.050}

(2 marks for the relationship and substitution). Then

|\varepsilon| = 250 \times \frac{0.030}{0.050} = 250 \times 0.60 = 150\ \text{V}

(2 marks for the answer with units). Once the flux is steady, $\dfrac{\Delta\Phi}{\Delta t} = 0$ , so the induced EMF is zero - induction depends on the rate of change of flux, not on the magnitude of the flux itself (2 marks).

Worked example

Question 3 (5 marks): Special relativity - time dilation

A spacecraft travels at $0.80c$ relative to Earth. An onboard clock measures a journey time of $3.0$ years (proper time). Calculate the time elapsed as measured by an observer on Earth.

Solution. The proper time $t_0 = 3.0$ years is measured in the spacecraft frame. The Earth observer measures the dilated time

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

(1 mark for the relationship). With $v = 0.80c$ , $\dfrac{v^2}{c^2} = 0.64$ , so

\sqrt{1 - 0.64} = \sqrt{0.36} = 0.60

(2 marks). Therefore

t = \frac{3.0}{0.60} = 5.0\ \text{years}

(1 mark). The Earth observer measures the longer time (1 mark) - moving clocks run slow, so the journey appears to take 5.0 years from Earth.

Common errors students made

The 2022 QCAA marker report flagged missing units, mixing scalar and vector quantities, treating projectile motion as one-dimensional, and students forgetting that induced EMF depends on the rate of change of flux rather than on flux itself. Add these recurring traps:

Combining horizontal and vertical motion incorrectly - using the resultant velocity in a vertical-only equation, or forgetting the horizontal velocity is constant.
Misusing the Lorentz factor - inverting the dilation formula, or confusing proper time with the observer's measured time.
No law named - stating an outcome (e.g. "the EMF is induced") without identifying Faraday's/Lenz's law and applying it.
Significant figures and units dropped at the final step, or scalar magnitudes reported where a vector direction is required.

How to use this paper

Sit Section 1 in 30 minutes, then Section 2 in ~85 minutes using only the QCAA data/formula sheet and a calculator. Mark against the official QCAA marking guide and marker report (linked in the frontmatter above) to see where method and reasoning marks fall. Re-attempt any extended-response item scoring below half, structuring it as named-law → applied relationship → result-with-units. Keep a formula-to-concept sheet (Faraday's law, time dilation, projectile components) and a checklist of units and vector directions to apply before submitting each answer.

Use this paper well

Sit the paper under exam conditions (120 minutes, 60 marks).
Mark yourself against the official QCAA marking notes.
Compare against the Physics hub to find the syllabus dot points this paper tested.

What this paper assessed

Structure and timing

Worked practice questions (exam-style)

Common errors students made

How to use this paper

Use this paper well

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