IGCSE Physics (0625): Complete Subject Guide

The challenge Physics 0625 sets for you

IGCSE Physics asks you to explain everyday phenomena with precision, then back up those explanations with calculations. Why does a car skid on a wet road? What determines the brightness of a bulb in a circuit? How does a power station convert fuel into electricity that reaches your home? The syllabus spans mechanics, thermal physics, waves, electricity, magnetism, nuclear physics, and space physics. Each area demands a different blend of conceptual understanding and quantitative problem-solving, and the exam papers test both in distinct ways.

The logical approach is straightforward: understand the paper structure first, then map the syllabus, then build a revision plan that allocates your time to the topics that carry the most marks. That's exactly the sequence this guide follows.

Who takes Physics 0625?

Cambridge IGCSE Physics is designed for students aged 14 to 16, typically in Year 10 and Year 11. It suits anyone considering A Level Physics, engineering, medicine, or any science-heavy pathway at university. The subject also carries weight for students targeting competitive university admissions, where a strong grade in a separate science carries more credibility than a combined award.

You don't need prior formal physics study, though a solid grasp of basic mathematics is essential. You'll regularly rearrange equations, substitute values with correct units, plot and interpret graphs, and work with standard form. If algebra and unit conversion feel comfortable, you're ready.

The six examination papers

Physics 0625 uses a tiered entry system. Core candidates sit Papers 1, 3, and either 5 or 6. Extended candidates sit Papers 2, 4, and either 5 or 6. Your school determines whether you take Paper 5 (a hands-on practical) or Paper 6 (a written alternative to practical).

Core candidates can achieve grades C to G. Extended candidates are eligible for grades A* to G, though the realistic floor for a well-prepared Extended candidate is around a D. If you're targeting an A or A*, Extended entry is mandatory.

Paper 1 and Paper 2: Multiple Choice

Both papers contain 40 questions in 45 minutes, giving you roughly one minute per question. Paper 1 (Core) tests content from the Core syllabus only. Paper 2 (Extended) covers the full syllabus, including Supplement content marked with a bold S in the syllabus document. There is no negative marking, so you should answer every question even if you're unsure.

The technique here is elimination. Read all four options before selecting. Cross out answers that contain obvious errors (wrong units, impossible magnitudes, contradictions with basic principles). If two options remain plausible, sketch a quick diagram or substitute a test value to distinguish them.

Paper 3 and Paper 4: Theory

These are the heavyweight papers at 50% of your total grade. You'll face structured questions that progress from simple recall (1-2 marks) through application (3-4 marks) to extended reasoning or calculation (5-6 marks). The mark-per-minute ratio works out to roughly one mark per minute, which is generous compared to many IGCSE subjects.

Each question typically opens with a context: a diagram of apparatus, a graph of experimental data, or a real-world scenario. The first part tests whether you can identify what's happening. Later parts ask you to explain, calculate, or predict. Working must be shown for all calculation questions. A correct final answer with no working typically earns zero marks if the question is worth more than one mark.

Paper 5: Practical Test

A hands-on examination where you carry out experiments using real apparatus. You'll measure, record data in tables, plot graphs, draw conclusions, and evaluate sources of error. The key skills tested are:

• Recording measurements to an appropriate degree of precision
• Repeating readings and calculating averages
• Plotting points accurately and drawing lines of best fit
• Identifying and explaining anomalous results
• Suggesting improvements to experimental method

Paper 6: Alternative to Practical

If your school doesn't offer Paper 5, you'll sit Paper 6 instead. This written paper presents experimental scenarios with diagrams and data, then asks you the same kinds of questions you'd face in a real practical: how would you set up the apparatus, what measurements would you take, how would you process the data, and what precautions would reduce error? You won't physically handle equipment, but you need to demonstrate that you understand practical method as if you had.

Core versus Extended: what's the difference?

The Core syllabus covers the fundamental principles in each topic area. Extended adds depth and complexity. Here's what that looks like in practice:

The Extended content isn't just "harder versions" of Core ideas. It introduces entirely new concepts (momentum conservation, the lens equation, electromagnetic induction) that don't appear at Core level at all. If you're sitting Extended papers, you need to study these topics from scratch, not just revise Core material more deeply.

The syllabus map: seven topic areas

The IGCSE Physics syllabus organises content into seven broad sections. Understanding how they connect helps you spot links that examiners like to test.

1. Motion, forces and energy

This is the largest section and the one that appears most consistently across past papers. It covers speed, velocity, acceleration, distance-time and velocity-time graphs, Newton's laws, mass versus weight, friction, turning effects (moments), centre of gravity, energy stores and transfers, work done, power, efficiency, and pressure. Extended students also tackle momentum, impulse, and the principle of conservation of momentum.

2. Thermal physics

Two sub-areas here: the kinetic particle model (states of matter, Brownian motion, gas pressure, evaporation) and thermal properties (temperature measurement, thermal expansion, specific heat capacity, specific latent heat, thermal energy transfer by conduction, convection, and radiation). The particle model questions tend to be conceptual. The thermal properties questions are often calculation-heavy, requiring you to apply E = mc(delta-T) or E = mL with careful unit handling.

3. Waves

Covers general wave properties (amplitude, frequency, wavelength, wave speed equation), sound (pitch, loudness, echoes, ultrasound), light (reflection, refraction, total internal reflection, lenses, dispersion), and the electromagnetic spectrum. Extended adds refractive index calculations using Snell's law and the critical angle formula.

4. Electricity and magnetism

Electric circuits dominate this section: current, voltage, resistance, Ohm's law, series and parallel rules, electrical energy and power calculations. Magnetism covers permanent magnets, electromagnets, the motor effect, electromagnetic induction, and transformers. This is the second most heavily tested area after forces. Circuit analysis questions appear on virtually every Paper 4 sitting.

5. Nuclear physics

Atomic structure, radioactive decay (alpha, beta, gamma), half-life, uses and dangers of radioactivity, nuclear fission and fusion. The section is smaller than the others but carries reliable marks. Half-life calculations and decay graph interpretation are particularly common.

6. Space physics

The solar system, orbital motion, stellar evolution, and the expanding universe. This section was introduced more recently and carries fewer marks overall, but the questions tend to be accessible and can provide straightforward marks for students who've revised it.

7. Practical skills (cross-cutting)

Not a content section in the traditional sense, but a set of skills assessed across Papers 5 and 6 and embedded in theory papers too. Planning experiments, identifying variables, drawing conclusions from data, and evaluating reliability all appear regularly in Paper 3/4 structured questions as well as in the dedicated practical papers.

Topics that carry the most weight

Not all topics are examined equally. Some areas appear on almost every paper, while others rotate in and out. Based on the pattern across many past paper sessions, these topics consistently attract the highest share of marks:

1. Forces - Newton's laws, free-body diagrams, friction, weight, resultant force calculations
2. Electric circuits - Series and parallel analysis, V = IR, combined resistance, power in circuits
3. Electrical quantities - Charge, current, voltage, resistance definitions and calculations
4. Transfer of thermal energy - Conduction, convection, radiation, insulation, real-world applications
5. Energy, work and power - KE and GPE calculations, work done, efficiency, Sankey diagrams
6. Light - Reflection, refraction, Snell's law, total internal reflection, lenses
7. Thermal properties and temperature - Specific heat capacity, latent heat, heating/cooling curves
8. Kinetic particle model - States of matter, Brownian motion, gas pressure, evaporation vs boiling

A rational revision strategy gives these eight topics disproportionate attention. They form the foundation of the subject and consistently account for the majority of available marks.

A tiered revision timeline

The plan below assumes you're sitting exams in May/June. Adjust the dates if your session is different, but keep the proportional time allocation.

12 months before the exam (June-September of the previous year)

• Complete your first pass through the entire syllabus with your school teaching
• Build a formula sheet as you go, adding each new equation with its units and a one-line description of when to use it
• Start a misconceptions log: every time you get a question wrong, write down what you thought and why it was incorrect
• Practise unit conversions until they're automatic (mm to m, g to kg, minutes to seconds, kWh to J)

6 months before (December-January)

• Begin topic-by-topic past paper questions, starting with the eight high-frequency areas listed above
• For each topic, work through questions from at least three different paper sessions
• Mark your own work using the published mark schemes, paying close attention to the exact wording Cambridge expects
• Identify your two or three weakest topics and schedule extra time for them

3 months before (March-April)

• Switch to full past papers under timed conditions
• Complete at least six full Paper 2 + Paper 4 sittings (or Paper 1 + Paper 3 for Core)
• After each timed paper, spend twice as long reviewing your errors as you spent writing the paper
• Practise Paper 6 questions if you're sitting the alternative to practical: these have a distinct style that rewards familiarity
• In the final two weeks, focus on your formula sheet and misconceptions log rather than new content

Paper-by-paper strategy

Multiple Choice (Papers 1/2)

1. First pass: answer every question you're confident about. Mark uncertain ones and move on.
2. Second pass: return to marked questions. Use elimination to narrow options.
3. Third pass (if time remains): review answers where you changed your mind. Your first instinct is usually correct unless you spot a specific error in your reasoning.
4. Never leave a question blank. With four options, a guess gives you a 25% chance.

Theory (Papers 3/4)

1. Read the entire question before writing anything. The later parts often clarify what the examiner is really asking in the earlier parts.
2. For calculations, write the formula first, then the substitution, then the answer with units. This "formula-substitution-answer" pattern earns method marks even if your arithmetic goes wrong.
3. For "explain" questions, use the structure: state the physics principle, apply it to the specific situation, then state the consequence. Three clear sentences typically earn full marks.
4. Watch the mark allocation. A 1-mark question needs one point. A 3-mark question needs three distinct points. Don't write a paragraph for a single mark.

Practical papers (Papers 5/6)

1. Record all measurements to the precision of the instrument. If a ruler measures to the nearest millimetre, record "23.4 cm" not "23 cm".
2. Always include units in table column headings, not next to individual values.
3. When plotting graphs, use more than half the grid in both directions. Choose scales that make plotting and reading easy (multiples of 1, 2, 5, or 10).
4. Draw a line of best fit that balances points on either side, not one that connects dot to dot.
5. When evaluating experiments, be specific. "Human error" is never an acceptable answer. Instead, identify which measurement was difficult to take accurately and explain why (parallax, reaction time, temperature loss to surroundings).

Practical skills that transfer to the theory papers

Even if you never sit Paper 5, practical reasoning appears in Papers 3 and 4. Examiners routinely ask you to describe how you would measure a quantity, identify variables in an experiment, suggest why results might be inaccurate, or propose improvements to a method. Students who've done hands-on practical work have a natural advantage here, but you can build the same skill set by studying experimental procedures and thinking through each step logically.

Common pitfalls across the subject

Building your equation toolkit

Physics 0625 requires you to recall and apply a specific set of equations. The syllabus lists them explicitly, and they're provided on a formula sheet during the exam, but relying on the sheet slows you down. Students who've internalised the key equations work faster and make fewer substitution errors.

The most frequently used equations across all topic areas are:

• v = s/t (speed = distance / time)
• a = (v - u)/t (acceleration)
• F = ma (Newton's second law)
• W = mg (weight)
• work done = F x d (in the direction of force)
• KE = 0.5 x m x v²
• GPE = m x g x h
• efficiency = useful output / total input x 100%
• P = E/t (power)
• p = F/A (pressure)
• V = IR (Ohm's law)
• P = IV (electrical power)
• E = IVt (electrical energy)
• v = f x lambda (wave speed)

Practise rearranging each equation for every variable it contains. If you can pick up any equation and isolate any term within five seconds, you're in strong shape for the calculation questions.

What a strong Physics candidate looks like

The students who score A* grades share several habits. They draw diagrams before they calculate, because a sketch clarifies the physical situation faster than re-reading the question three times. They write the relevant equation before substituting numbers, because this earns method marks even when the arithmetic goes wrong. They answer in complete physics sentences when a question says "explain" or "describe", because single-word answers rarely earn full marks on extended response questions. And they practise under timed conditions regularly, because exam technique under pressure is a separate skill from understanding the physics.

Physics 0625 rewards systematic preparation. The syllabus is well-defined, the question styles are predictable, and the mark schemes are transparent. Candidates who map the territory, practise strategically, and refine their technique consistently reach the top grades.