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IB Physics Mock Paper (first assessment 2025): Paper 1 Data Questions and Paper 2 Extended Response with Answers
TUTORZONE ORIGINAL MOCK PAPER · IB PHYSICS (first assessment 2025)
Written to the IBO subject brief for first assessment 2025: Paper 1 (multiple-choice plus data-based questions) is 36%% (SL 1.5 h / HL 2 h), Paper 2 (short-answer and extended-response) is 44%% (SL 1.5 / HL 2.5 h) and the scientific investigation is 20%%. This paper has 10 MC items, 2 data-based and 2 extended-response questions with answers and mark allocation.
How are Paper 1 and Paper 2 weighted in IB IB Physics?
Direct answer: per the IBO subject brief for first assessment 2025, Paper 1 (1A multiple-choice + 1B data-based) is 36% of the final grade (SL 1.5 h / HL 2 h), Paper 2 (short-answer and extended-response) is 44% (SL 1.5 / HL 2.5 h) and the scientific investigation is 20%.
Assessment at a glance (2027)
| Component | Content | Weighting | Duration |
|---|---|---|---|
| Paper 1 (1A multiple-choice + 1B data-based) | All syllabus themes; 36% of the final grade | 36% | SL 1.5 h / HL 2 h |
| Paper 2 (short-answer + extended-response) | Short-answer and extended-response; 44% of the final grade | 44% | SL 1.5 h / HL 2.5 h |
| Scientific investigation (IA) | Open-ended investigation, 20% of the final grade (10 recommended hours) | 20% | done in school |
Paper 1B marks come from reading, calculation and unit – miss one and you lose the mark. Paper 2 extended-response answers should be point, mechanism, example, with evidence behind every claim. Finish 1A in about 25 minutes and spend the rest on 1B and the essays.
How this paper was built
This is a TutorZone original mock paper: the questions follow the Paper 1/Paper 2 formats of the 2025 first assessment and the answers are our own, not IB past papers or official marking references; only the 36/44/20 weightings come from the IBO subject brief.
The IB publishes no fixed question count, so this paper sets its own: 10 MC items, 2 data-based questions and 2 extended-response questions. Every numeric answer was recomputed programmatically.
Pacing
| Section | Marks | Suggested time | What to do first |
|---|---|---|---|
| Paper 1 (1A multiple-choice + 1B data-based) | 36% | about 25 min for 1A, 45 for 1B (SL) | On 1B show reading, calculation and unit |
| Paper 2 (short-answer + extended-response) | 44% | roughly 70% short-answer, 30% extended-response | Structure essays as point, mechanism, example |
| Scientific investigation (IA) | 20% | not covered here | Handled by your school; this page trains Papers 1 and 2 |
How do I score fully on Paper 1B data questions?
Direct answer: write all three: the value read from the graph with its unit, the formula and substitution, and the answer with significant figures. Marks are allocated to those three steps, so a bare final answer earns only the answer mark.
Paper 1A: multiple-choice (10 questions)
Aim for about 25 minutes at SL.
Question 1
A cart accelerates uniformly from rest at 2 m s⁻² for 2 s. Its speed is?
A. 1 m s⁻¹B. 4 m s⁻¹C. 2 m s⁻¹D. 8 m s⁻¹
Question 2
A 0.5 kg body moves at 4 m s⁻¹. Its kinetic energy is?
A. 4 JB. 16 JC. 2 JD. 8 J
Question 3
A wave of frequency 500 Hz has wavelength 0.68 m. Its speed is?
A. 340 m s⁻¹B. 735 m s⁻¹C. 500 m s⁻¹D. 68 m s⁻¹
Question 4
A photon has frequency 5 × 10¹⁴ Hz. Its energy is (h = 6.63 × 10⁻³⁴ J s)?
A. 1.3 × 10⁻¹⁹ JB. 3.3 × 10⁻¹⁹ JC. 3.3 × 10⁻³⁴ JD. 7.5 × 10⁴⁷ J
Question 5
An ideal gas occupies 0.024 m³ at 100 kPa and 300 K. Its amount in moles is about (R = 8.31 J mol⁻¹ K⁻¹)?
A. 9.6 molB. 0.96 molC. 96 molD. 0.096 mol
Question 6
A 12 V supply drives 3 A. The resistance is?
A. 4 ΩB. 3 ΩC. 36 ΩD. 0.25 Ω
Question 7
A 5 Ω resistor carries 2 A. Its power is?
A. 40 WB. 2.5 WC. 10 WD. 20 W
Question 8
A body moves at 4 m s⁻¹ on a circle of radius 2 m. Its centripetal acceleration is?
A. 2 m s⁻²B. 32 m s⁻²C. 4 m s⁻²D. 8 m s⁻²
Question 9
After four half-lives, how much of a 64 g sample remains?
A. 8 gB. 16 gC. 2 gD. 4 g
Question 10
In SI units, momentum is measured in?
A. kg m s⁻²B. J s⁻¹C. N mD. kg m s⁻¹
Paper 1B: data-based questions (2 questions)
Aim for about 45 minutes. Read the values off the graph, calculate, then give the unit.
Question 1 (8 marks)
Experimental data: a 2.0 kg block is pulled along a horizontal surface with different forces F and its acceleration a is measured.
F / N: 2.0, 4.0, 6.0, 8.0; a / m s⁻²: 0.8, 1.9, 3.1, 4.0.
(a) Plot a against F, find the gradient and state its meaning; (b) hence find the friction on the block; (c) state one source of error and how it affects the result.
Question 2 (7 marks)
A circuit has a cell of emf 6.0 V and internal resistance 0.5 Ω connected to an external resistor of 2.5 Ω. (a) Find the current; (b) find the terminal voltage; (c) find the power wasted inside the cell; (d) explain why the terminal voltage is less than the emf.
Paper 2: short-answer and extended-response (2 questions)
Use point, mechanism, example for each extended answer.
Question 1 (12 marks)
Discuss how conservation of energy applies to (a) free fall with air resistance and (b) losses in power transmission through transformers, giving a measurable example in each case.
Question 2 (10 marks)
Describe an experiment to measure the acceleration due to gravity g, covering variable control, data handling and two main sources of error.
Where are the answers, and is there a mark allocation?
Direct answer: each question is followed by an answer-and-marks block: data questions give the reading, the working and the unit, and extended answers give each point with its mechanism, example and marks, ready to use as a self-marking sheet.
Paper 1A answers and explanations
Question 1
Answer: B (4 m s⁻¹) v = u + at = 0 + 2 × 2.
Question 2
Answer: A (4 J) Eₖ = ½mv² = ½ × 0.5 × 16.
Question 3
Answer: A (340 m s⁻¹) v = fλ = 500 × 0.68.
Question 4
Answer: B (3.3 × 10⁻¹⁹ J) E = hf = 6.63 × 10⁻³⁴ × 5 × 10¹⁴.
Question 5
Answer: B (0.96 mol) n = pV ÷ RT = 100 000 × 0.024 ÷ (8.31 × 300).
Question 6
Answer: A (4 Ω) R = V ÷ I = 12 ÷ 3.
Question 7
Answer: D (20 W) P = I²R = 4 × 5.
Question 8
Answer: D (8 m s⁻²) a = v² ÷ r = 16 ÷ 2.
Question 9
Answer: D (4 g) 64 → 32 → 16 → 8 → 4 g.
Question 10
Answer: D (kg m s⁻¹) Momentum p = mv, so kg m s⁻¹ (equivalently N s).
Paper 1B answers and mark allocation
Question 1
(a) The graph is close to straight with gradient ≈ (4.0 − 0.8) ÷ (8.0 − 2.0) = 0.53 kg⁻¹ (3 marks) – since F − f = ma gives a = (1/m)F − f/m, the gradient is 1/m, which for 2.0 kg should be 0.5 kg⁻¹, so the trend is sound but has a systematic offset (2 marks); (b) extrapolating to a = 0 gives F ≈ 1.0 N, so friction is about 1 N (2 marks); (c) uneven contact, a non-horizontal force sensor or timing error would lower a or tilt the gradient (1 mark).
Question 2
(a) I = ε ÷ (R + r) = 6.0 ÷ 3.0 = 2.0 A (2 marks); (b) V = IR = 2.0 × 2.5 = 5.0 V (2 marks); (c) P = I²r = 4 × 0.5 = 2.0 W (2 marks); (d) part of the emf is dissipated in the internal resistance (the lost volts Ir = 1.0 V), so V = ε − Ir (1 mark).
Paper 2 answers and mark allocation
Question 1
(a) In free fall gravitational potential energy becomes kinetic; with air resistance some becomes internal (thermal) energy, so mgh is greater than ½mv² (3 marks). Measurable example: compare a measured landing speed’s ½mv² with mgh, the deficit being the work done against drag (2 marks). (b) Transmission lines dissipate P = I²R, and raising the voltage lowers the current for the same power, cutting losses sharply (3 marks). Measurable example: compare cable temperature rise or voltage drop at high and low transmission voltages for the same power (2 marks). Conclusion: conservation of energy requires accounting for every loss (2 marks).
Question 2
Method: free fall timed with a data logger or light gates, measuring the time t for several heights h (2 marks). Control: same object and release method, minimising drag by using a small dense sphere (2 marks). Data handling: plot h against t², whose gradient is g ÷ 2, so g = 2 × gradient; or take repeated readings and examine the spread (3 marks). Errors: human reaction time in release and timing; air resistance and gate alignment, both tending to make g come out low (3 marks).
Where are marks most easily lost on this paper?
Direct answer: data questions without a recorded reading; essays that list points with no mechanism; ignored significant figures and uncertainty; and answering HL questions at SL depth or the reverse. All four are cases of knowing the science but writing too little.
Where these marks are usually lost
| Mistake | What it looks like | What it costs | Instead |
|---|---|---|---|
| No reading recorded on data questions | Straight to the calculation | 1B marks are reading, calculation and unit – each is separate | Write the value read off the graph, then the working, then the unit |
| Listing points in an essay | Three lines of bullet points | Extended-response answers need mechanism and example | Add a mechanism and a syllabus example to every point |
| Ignoring uncertainty | A single bare number | IB science marks uncertainty and significant figures | State the accuracy and identify a source of error |
| Confusing SL and HL depth | One depth for both | HL expects deeper mechanisms and quantitative treatment | Decide whether you sit SL or HL first |
How to use this paper
First sit: no references, timing Paper 1 (25 minutes for 1A, 45 for 1B) and Paper 2 as separate blocks.
Mark it: check reading, calculation and unit on every data part, and that each essay point carries a mechanism and an example.
Second sit: redo it three to seven days later aiming to hit every mark-allocation point on the essays.
What should I do after this paper?
Direct answer: turn reading-calculation-unit into a fixed template for data questions; template the extended answers as point, mechanism, example; drill by topic and keep an uncertainty-analysis note; then redo this paper three to seven days later.
FAQ
Is this an IB paper?
No. The questions, answers and mark allocation are TutorZone originals; only the weightings (Paper 1 36%, Paper 2 44%, investigation 20%) come from the IBO subject brief for first assessment 2025.
What is the difference between SL and HL?
Paper 1 runs 1.5 h at SL and 2 h at HL; Paper 2 runs 1.5 h at SL and 2.5 h at HL, with greater depth and breadth at HL. These questions cover the SL core, with extension work left for HL students.
How do I prepare for the IA?
It is done in school and worth 20%: research question, variable control, data processing and uncertainty analysis. This page trains Papers 1 and 2.
Official references
| Resource | What to check |
|---|---|
| https://www.ibo.org/programmes/diploma-programme/curriculum/sciences/ | IBO DP sciences curriculum and subject briefs (first assessment 2025) |
| https://www.tutorzone.com.hk/en-ib-physics-past-paper-drill-guide/ | IB Physics drilling guide: pacing and answering frames for Papers 1 and 2 |
Related: practice area · IB Maths AA SL mock
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