IPhO Problem Sets (Official Problems + Hints)
Curated IPhO theory and experimental problems by technique, with solution outlines and links to official PDFs.
On this page
These problem sets are built from official IPhO papers (theory + experimental). Each set groups problems by technique and gives solution outlines and common traps, without reproducing copyrighted statements.
Problem statements and official solutions remain the property of IPhO and the hosting organizers. Use the linked PDFs for the full text.
This page links to PDFs via the public IPhO archive (often mirrored). If a link ever fails, start from:
- IPhO official documentations: https://www.ipho-new.org/documentations/
- IPhO archive mirror index: https://phoxiv.org/contests/ipho
- Follow a hub’s lesson path until you can solve 2 to 3 problems without notes. 2. Do 1 problem timed, then spend more time on the post-mortem than the attempt. 3. Keep a one-page error log: “what I missed, why, and what to do next time”.
Use a fading-hint practice ladder
- Prepare: read the problem-solving framework and the relevant Entry/Core lesson.
- Guided attempt: read the problem, reveal the outline, then complete every algebraic and checking step yourself.
- Partial support: use only the first useful hint. Stop reading as soon as you can continue.
- Independent attempt: retry after 48–72 hours without notes. Add timing only after the setup is reliable.
New to IPhO? Do This First
These “foundation” lessons are written to be beginner-friendly and to teach the habits that make official problems solvable.
Problem-Solving Framework (Beginner-Friendly)
A reusable checklist: modelling, method choice, approximations, checks.
Modelling & Approximations
How to simplify without losing the physics.
Scaling & Dimensional Analysis
Nondimensionalise, spot balances, and bound errors.
Electrostatics with Symmetry
Choose surfaces/arguments where symmetry collapses the algebra.
First Law Problem Patterns
System definition, signs, and fast bookkeeping.
Phasors & Superposition
Add oscillations fast and track phase reliably.
Special Relativity Toolkit
Invariants, frames, and fast consistency checks.
Uncertainty & Error Propagation
Uncertainty habits for experimental marks and clean conclusions.
Pick a Set
Mechanics Problem Set
Constraints, oscillations, central forces, fluids, and experimental mechanics.
Electricity & Magnetism Problem Set
Symmetry, circuits/transients, magnetostatics, induction, and experimental E&M.
Thermodynamics & Statistical Physics Problem Set
First/second law patterns, distributions, transport, and real-world modelling.
Waves & Optics Problem Set
Wave models, interference/diffraction, polarization, and optics experiments.
Modern Physics Problem Set
Relativity/quantum/nuclear plus astrophysics-style modern problems.
Math Tools Problem Set
Scaling, ODE patterns, vector calculus symmetry, matrices, and estimation.
Experimental Skills Problem Set
Experimental papers plus write-up and evaluation routines.
A Minimal “Outline-First” Workflow
What counts as a good IPhO solution outline?
A good outline is a 10 to 15 line plan that makes the marker confident you know what you are doing:
- define the system + coordinates + sign conventions
- state assumptions and justify one approximation with a ratio
- write the core conservation law / model equation
- show the key intermediate quantity you are solving for
- list 2 sanity checks (units + one limit)
If your outline does not mention assumptions, scales, or checks, it is usually not olympiad-grade yet.