Themes A–E Topics Paper Split Cross-Topic Difficulty Grade Boundaries Predicted Papers
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IB Physics HL Paper Analysis — New 2025 Syllabus

Marks-weighted analysis of 307 questions across 900 marks and 18 papers — every sitting of the redesigned IB Physics Higher Level course so far. Theme A–E weightage, the Paper 1A / 1B / 2 split, and the cross-topic synthesis that now dominates the exam.

New syllabus only. This analysis covers exclusively the redesigned 2025 IB Physics course — the 2025 specimen, May 2025 (TZ1/TZ2/TZ3) and November 2025 (TZ1/TZ3) papers, the first sittings of the new programme. Older papers are deliberately excluded because the syllabus, themes and paper structure have all changed, so pre-2025 papers no longer reflect what is examined.
Key finding 54.2% of all marks are multi-topic — Paper 2 is 79% synthesis See Why
307
Questions Analysed
900
Total Marks
18
Papers
6
New-Syllabus Sittings
Methodology: Every question in all 18 papers was tagged by theme and sub-topic. When a question carries multiple topic tags, its marks are distributed equally among the tags — a 12-mark question tagged "Forces & momentum" and "Gravitational fields" contributes 6 marks to each — so nothing is double-counted and the weightings reflect what the exam actually tests by marks. Scope: only the new 2025 syllabus is included (2025 specimen, May 2025 TZ1/TZ2/TZ3 and Nov 2025 TZ1/TZ3). The papers follow the new structure — Paper 1A (multiple choice), Paper 1B (data-based / experimental) and Paper 2 (extended response); there is no Paper 3.

Theme Weightage by Marks — the 5 Themes (A–E)

Percentage of total exam marks allocated to each of the five syllabus themes across all 18 papers, with marks distributed among tags to avoid double-counting.

Share of marks by theme

Themes ranked by marks

Topic Weightage by Marks — All 24 Sub-Topics

Every sub-topic ranked by its share of total exam marks. Bars are coloured by theme. HL-only sub-topics are marked "(HL)".

Biggest Topic

A.2 Forces & momentum = 11.3% of marks

The single largest sub-topic by marks, and the most paper-agnostic — it carries 17.0 marks on Paper 1A, 35.8 on 1B and 49.2 on Paper 2. Mechanics is the backbone of the new course.

Theme A leads

Space, time & motion = 27.7%

Theme A (kinematics, forces, energy, rigid-body HL, special relativity HL) is the heaviest theme by a clear margin — over a quarter of every mark on offer.

HL depth

Five HL-only sub-topics

B.4 Thermodynamics, E.2 Quantum physics, A.5 Special relativity, D.4 Induction and A.4 Rigid-body mechanics are HL-only — together they carry roughly 17% of HL marks and are almost never seen on Paper 1A alone.

Lightest

B.2 Greenhouse effect = 1.1%

The smallest sub-topic by marks — but still examined every sitting, usually as a short data or definition item. Low weight does not mean skippable.

Where Each Theme Lives — Paper 1A vs 1B vs 2

The new structure splits assessment three ways: Paper 1A (multiple choice), Paper 1B (data-based / experimental) and Paper 2 (extended response). This chart shows the marks each theme carries on each paper — Paper 2 is where almost all the depth (and synthesis) lives.

Paper 2 = depth

~60% of every theme's marks sit on Paper 2

Across all five themes, Paper 2 (extended response) carries the majority of the marks. It is the paper that decides grades — and, as the next section shows, the paper that blends topics the hardest.

Paper 1B skew

Data paper favours mechanics & matter

Theme A (forces, energy) and Theme B (thermal, gas laws, circuits) dominate the data-based Paper 1B, where experiments on motion, heating and electrical measurement are easiest to set. Fields (D) barely appear on 1B.

Everywhere

No theme is confined to one paper

Unlike the old course, every theme shows up on all three papers. There is no "Paper 1A-only" or "Paper 2-only" theme to revise in isolation.

★ The headline story

Cross-Topic Synthesis: why the new Physics papers punish gaps

The redesigned exams were deliberately built to blend themes inside a single question. You are no longer answering "a mechanics question" or "a nuclear question" — you are answering one long question that starts in mechanics, moves through fields, and finishes in nuclear or quantum. Revising topics in isolation is no longer enough: the marks live in the connections.

54.2%
of all marks sit in questions that combine 2 or more distinct topics (55 questions, 17.9% of all questions).
64.2%
of Paper 2 questions are multi-topic — 34 of 53 — and they carry 79.1% of all Paper-2 marks.
28
questions fuse 2 or more different themes (A–E) inside one question — mechanics ↔ fields, matter ↔ nuclear, and more.

Paper 2 is the clearest signal of the shift: nearly four out of five of its marks are in synthesis questions. A single 20-mark extended-response item can require energy conservation, a field equation, and a nuclear or quantum result — all chained together, where an early slip in one theme sinks the marks that follow. The examiners reward students who can connect themes, not just recall them.

Most common theme pairings in one question

A + D Space, time & motion + FieldsOrbital & projectile motion meeting gravitational / electromagnetic fields. ×11
B + E Particulate matter + Nuclear & quantumThermal / internal energy tied to nuclear decay, fusion and quantum energy levels. ×9
B + C Particulate matter + Wave behaviourGas / thermal physics linked to sound, standing waves and resonance. ×6
A + C Space, time & motion + Wave behaviourOscillations, SHM and the Doppler effect built on kinematics. ×6
D + E Fields + Nuclear & quantumCharged particles in fields meeting atomic, nuclear and photon physics. ×4
A + E Space, time & motion + Nuclear & quantumMomentum & energy conservation applied to radioactive and stellar contexts. ×4

Hardest mixed-concept questions we've seen

  • Spec TZ0Energy conservation combined with Coulomb potential at the nucleus.
  • N25 TZ3Free-body / Newton's laws + circular-motion friction + work–energy on a semicircle.
  • N25 TZ3Rotational dynamics / moment of inertia + energy conservation + angular momentum.
  • N25 TZ3Atomic mass & spacing estimates + latent heat and internal energy + standing waves in a rod/pipe and the speed of sound.
  • N25 TZ3Radiation pressure / photon momentum + kinematics of a solar sail + orbital mechanics and Kepler density.
  • M25 TZ2Fusion conditions + stellar equilibrium + mass-defect energy + main-sequence lifetime + Wien peak wavelength + Doppler rotation period.
  • M25 TZ2Variable-mass drag force + orbital total energy + energy-dissipation rate + orbital speed + heating (specific heat) + fuel volume.
  • M25 TZ3Static / dynamic friction + work–energy for stopping distance + torque / tipping about a corner (rigid body).

How to prepare for a synthesis exam

  • Practise the connections, not just the chapters. Drill deliberately across theme pairs — mechanics ↔ fields, matter ↔ nuclear, waves ↔ thermal — so the joins feel routine under time pressure.
  • Drill full Paper 2 extended-response questions. With 79% of Paper-2 marks in multi-topic items, working complete long questions (not isolated parts) is the single highest-value revision you can do.
  • Fix your weak theme first. Because early sub-parts feed later ones, one shaky theme can cost you marks in three others. There are no safe gaps in the new course.
  • Get tutor-led linking. A tutor who has mapped these combinations can show you the recurring "bridges" between themes and the standard chains examiners reuse — see Photon's IB Physics tuition.

Difficulty Spread

Every one of the 307 questions rated for demand. Most of the paper is squarely mid-difficulty — but roughly one question in five is genuinely hard, and those hard questions are overwhelmingly the multi-topic Paper 2 items above.

Questions by difficulty

What the spread tells you

Accessible · 60

~20% of questions are entry-level

Recall, single-step and "state / define" items — mostly on Paper 1A and the opening parts of longer questions. Reliable marks if fundamentals are solid.

Medium · 186

The bulk of the exam is mid-demand

Over 60% of questions need two or three linked steps. This is where most candidates win or lose their grade — through accuracy and setting-out, not exotic content.

Hard · 61

~20% are genuinely hard — and multi-topic

These are the long synthesis questions that chain themes together. Handling them is what separates a 6 from a 7.

IB Grade Boundaries — Physics HL

Official grade boundaries for the new syllabus.

Coming soon

Physics HL boundary data is being compiled

Because the redesigned course has only just had its first sittings, we are still gathering and verifying the official IB grade-boundary documents for Physics HL. Rather than publish estimated or fabricated numbers, we are leaving this section blank until we have confirmed data. Check back — or ask your IB coordinator for the official boundaries in the meantime.

Photon Physics HL Predicted Papers

Full IB-style predicted papers for the new Physics HL course — Paper 1A, 1B and 2 with markschemes — modelled on the synthesis patterns above.

In development

Physics HL predicted papers are on the way

Our tutors are currently writing predicted paper sets for the redesigned Physics HL course, built to mirror the cross-topic Paper 2 style this analysis uncovered. They are not published yet. In the meantime, the fastest way to prepare for a synthesis exam is targeted, tutor-led practice on the exact theme combinations that keep recurring.

Preparing for the new IB Physics HL exam?

The 2025 course rewards students who can connect themes across a single Paper 2 question. Photon Academy's IB Physics tutors drill exactly those cross-topic chains, one weak link at a time.

Explore IB Physics Tuition