Paper 1B is the part of the IB Physics exam that catches students out most often. Not because the physics is harder than Paper 2. But because the skills it tests are genuinely different, and most students don’t realise that until they’re sitting in the exam.
Here’s what you need to know.
What is Paper 1B?
Paper 1B is the data-based section of the IB Physics exam. It is worth 20 marks for both SL and HL and is sat in the same session as Paper 1A (the multiple choice). You have a combined 1 hour for both papers at SL, and 1 hour 15 minutes at HL.
The questions are based on unfamiliar experimental scenarios. You will be given data, a graph, a table, or a description of an experiment you have never seen before, and asked to analyse it. There are no multiple choice options. You write your answers in full.
For a full breakdown of how Paper 1B fits into the exam overall and what each paper is worth, read the IB Physics exam breakdown guide.
Why Paper 1B is hard to revise for
There are two reasons, and they are connected.
First: there are very few official past papers. The current IB Physics syllabus was first examined in 2025, which means there is a limited bank of real Paper 1B questions to practise from. For Paper 2 and Paper 1A, you can work through years of official past papers. For Paper 1B, you cannot.
Second: the skills it tests were removed as a standalone topic. In the previous IB Physics syllabus, Topic 1 (Measurements and Uncertainties) was an entire dedicated unit covering significant figures, error analysis, graph skills, and uncertainty propagation. Under the current syllabus, these skills are no longer a named topic. They are described as skills to be embedded throughout the course.
In practice, that means many students reach the exam without having formally revised them. Teachers cover them, but often in passing, and students tend not to prioritise skills that don’t appear as a named topic on a checklist.
Paper 1B tests exactly these skills, in depth, under time pressure.
What Paper 1B actually tests
The same skill categories come up again and again. If you know these cold, the paper becomes very manageable.
Uncertainty calculations
You need to be able to calculate absolute, fractional, and percentage uncertainty. You need to know how uncertainties combine when you add, subtract, multiply, divide, or raise values to a power. You need to identify the dominant source of uncertainty in an experiment and explain why it matters.
Graph skills
Drawing a best-fit line through data points (and knowing it does not have to pass through every point). Drawing the steepest and shallowest plausible lines to estimate the uncertainty in a gradient. Calculating a gradient correctly, with units. Identifying whether a relationship is linear, inversely proportional, or something else, from the shape of the graph.
Key definitions
These come up almost every session. You need exact, concise definitions for: accuracy, precision, random error, systematic error, resolution, and the distinction between repeatable and reproducible results. Vague answers lose marks. The mark scheme expects specific language.
Applying physics to unfamiliar contexts
Paper 1B will give you an experiment you have not seen before. It might use an unusual setup or measure an unexpected quantity. Your job is to apply your physics knowledge to that new context. This is a skill you build through practice, not memorisation.
How to prepare
Build your definitions list first
Write out a single page with the exact definitions the examiners expect. Learn them properly. This takes an hour and immediately makes you more confident in any Paper 1B question that asks you to “state the meaning of” or “explain the difference between.”
Practise uncertainty calculations until they are automatic
Work through enough examples that you don’t have to think about the rules. The calculation itself is never difficult, but students lose marks by applying the wrong rule under time pressure.
Practise graph skills with a ruler
Draw best-fit lines. Draw max and min gradient lines. Calculate gradients from graphs, including the units. This sounds obvious but many students arrive at the exam without having practised it with pencil and paper.
Use a question bank
Because official past papers are limited, you need a wider bank of Paper 1B-style questions to practise from. The GradePod Exam Pack includes over 150 marks of Paper 1B practice questions with full answers, a complete maths skills checklist, and the key definitions list you need. It is the most efficient way to build the skills Paper 1B tests, without spending hours hunting for resources.
Paper 1B rewards preparation. The students who struggle are the ones who treat it as a paper you just turn up to.
A note on time
You sit Paper 1B immediately after Paper 1A in the same exam session. SL students have 1 hour for both papers combined, HL students have 1 hour 15 minutes. Paper 1A (the multiple choice) should take around 30 minutes for SL and 40 minutes for HL, which leaves you 30 minutes for Paper 1B.
Thirty minutes for 20 marks is tight if you are uncertain about the skills. It is very manageable if you have practised.
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Sally Weatherly is a Fellow of the Institute of Physics, author of 4 IB Physics books (two hit #1 on Amazon), and has been teaching IB Physics since 2004. GradePod has helped 30,000+ students since 2020.