IB Physics: The Complete Study Guide

The direct answer: IB Physics is a Group 4 science in the IB Diploma Programme, studied over two years at Standard Level (SL) or Higher Level (HL). The current syllabus, first assessed in May 2025, organises content into five themes and asks every student to complete a scientific investigation worth about 20 percent of the grade. The biggest change from the older version is the removal of optional topics and the shift to a connected, theme based structure, so revision should link ideas across the course rather than study them in isolation.

IB Physics at a Glance

The official Physics guide (first assessment 2025) sets out the five themes and confirms the structure (IB Physics guide, first assessment 2025). Third party breakdowns of the same specification are useful for checking coverage, for example the Save My Exams syllabus update and the GradePod topic list.

The 2025 Syllabus and Its Five Themes

The 2025 syllabus groups physics into five themes instead of a long list of disconnected topics:

• Space, time, and motion: kinematics, forces, work, energy, and an introduction to special relativity.
• The particulate nature of matter: thermal physics, gas laws, and the structure of matter.
• Wave behaviour: oscillations, waves, and wave models including interference.
• Fields: gravitational, electric, and magnetic fields.
• Nuclear and quantum physics: atomic structure, nuclear processes, and quantum ideas.

Measurement and uncertainties run across the whole course and show up in data questions and the investigation. SL covers the core of each theme, while HL covers all of that plus additional material and some HL only topics such as rigid body mechanics, special relativity, thermodynamics, and induction (MyRevisionAgent IB Physics guide). The teaching hours tell the story: 150 hours at SL and 240 at HL, with Theme A (Space, time, and motion) getting the most time at both levels (GradePod hours table).

How IB Physics Is Assessed

External exams make up about 80 percent of the grade and the internal assessment about 20 percent. Under the 2025 syllabus the external papers are structured as follows:

• Paper 1A: multiple choice questions testing knowledge across the themes.
• Paper 1B: data based questions on graphs, units, and uncertainties.
• Paper 2: short answer and extended response questions drawing on the themes, with HL adding more depth and marks.
• The internal assessment is a written scientific investigation, up to about 3,000 words, where you design, carry out, and report an experiment of your choice.

The 2025 syllabus also replaced the older Group 4 Project with a Collaborative Sciences Project, where students from different sciences work together on a shared question. It is a Core experience rather than a separately graded component in the same way as before.

The scientific investigation

This is the internal assessment, worth about 20 percent. A simple experiment done rigorously scores better than an ambitious one with weak data. You need a question you can measure repeatedly, variables you control, and analysis that includes uncertainties. The IB provides a data booklet in the exam, so questions test whether you can select the right equation and apply it, not whether you can recall every formula (MyRevisionAgent on the data booklet).

Standard Level Versus Higher Level

Both levels share the same five themes, but HL asks for more. The difference is mostly depth within each theme plus a handful of HL only topics, not a separate body of content. HL also has a longer Paper 2 with more marks available.

What this means for study

If you are taking HL, budget for the extra topics early. Students often assume SL and HL diverge entirely, but the boundary is really about how far each theme is taken. The practical implication is that HL revision cannot skip the shared core, and SL revision should not be tempted into HL only material that will not be examined.

Picking the level

Choose HL if your target degree is physics, engineering, or a related field and your school strengths support it. Choose SL if physics is a support subject or your workload is already full. Either way, the 20 percent investigation weighting is identical, so the project matters at both levels.

Study Strategies That Work

Build uncertainty skills early

Measurement and uncertainties appear in Paper 1B and throughout the investigation. Learn to propagate errors for sums, products, and powers, and to draw graphs with error bars and lines of best fit. This is a specific IB skill that takes time, and examiners look for it across the write up, not just in the conclusion.

Link the themes

IB Physics rewards connections. A forces question may draw on energy and motion together, and Paper 2 often expects you to link concepts across themes (MyRevisionAgent on linking). Practise mixed questions that cross themes rather than revising each in isolation.

Treat the investigation as a real project

Start the internal assessment early. Choose a question you can measure repeatedly, control variables, and analyse with uncertainties. A small, well controlled experiment beats a spectacular one with messy data.

Use spaced, mixed practice

Rotate themes each week and return to older ones so the material stays active. Past papers from the old syllabus (last assessed 2024) are useful for drilling individual concepts, but the theme structure and paper format differ, so use them as topic practice rather than mock exams (MyRevisionAgent on past papers).

Common Misconceptions

• "Themes mean topics are taught in order." The guide does not prescribe teaching order, so your school may sequence them differently.
• "Uncertainty is a minor skill." It appears across papers and the investigation and is explicitly rewarded.
• "HL is just SL with more questions." HL adds genuinely separate topics such as special relativity and induction.
• "The data booklet means I don't need to know formulae." You still must select and apply the right relationship under time pressure.
• "The old past papers are identical." They are not; the 2025 course is a real break from the previous syllabus.

Frequently Asked Questions

Is IB Physics SL or HL harder?

Both share the core, but HL adds depth, extra topics, and a longer paper. HL is more demanding and more mathematical, which suits physics or engineering paths.

Do universities accept IB Physics?

Yes. It is recognised widely for science degrees, and HL is valued for physics, engineering, and related fields.

What changed in the 2025 syllabus?

Content was reorganised into five themes, the separate options were removed, and the Group 4 Project became a Collaborative Sciences Project. Assessment now uses the 1A, 1B, and Paper 2 structure.

How long is the internal assessment?

The scientific investigation report is up to about 3,000 words and worth around 20 percent of the grade.

Is a graphing calculator needed?

A scientific calculator is the usual requirement for physics; check your school's exam rules. The maths course has its own calculator expectations, which are separate.

How should I start revising?

Open the official 2025 subject guide and map what you have covered against the five themes, then build a weekly plan that rotates themes and includes uncertainty practice from the start.