Cambridge International · IGCSE · 0625
Physics — Keywords & Key Terms — Definitions Glossary (2026)
Cambridge IGCSE Physics (0625)
Topic-by-topic keywords, key terms and definitions for precise exam language—separate from our revision checklists (topic coverage) and formula sheets (equations).
Keywords & Key Terms — definitions
Examiner-style keywords and definitions organised by syllabus topic. Terms are tagged Essential (start here), Core (typical exam standard), and Advanced for harder distinctions — tick each row when you can recall it. Your progress is saved in this browser for this list.
Cambridge International IGCSE Physics (0625)
Cambridge International IGCSE Physics (0625)
Cambridge IGCSE Physics (0625)
Topics follow the Cambridge IGCSE Physics 0625 syllabus for 2026 (Core and Extended). Extended candidates cover all objectives; Core omits some Extended-only content — check your entry for Core vs Extended papers.
Mark schemes: Marks reward precise scientific vocabulary, clear algebra in calculations, and logically linked physical reasoning. Practical papers (5/6) often assess measurement technique, handling of anomalies, uncertainty, and correct interpretation of gradients and intercepts on graphs.
Active recall: 0 / 80 terms ticked
| Recalled | Topic | Level | Keyword | Definition |
|---|---|---|---|---|
| 1. Motion, forces and energy | Essential | Distance | How far an object has travelled along a path (scalar). | |
| 1. Motion, forces and energy | Essential | Displacement | Straight-line distance and direction from start to finish (vector). | |
| 1. Motion, forces and energy | Core | Speed | Distance travelled per unit time; scalar. | |
| 1. Motion, forces and energy | Core | Velocity | Rate of change of displacement; vector quantity. | |
| 1. Motion, forces and energy | Core | Acceleration | Rate of change of velocity; a = (v − u)/t. | |
| 1. Motion, forces and energy | Core | Newton’s first law | A body stays at rest or uniform velocity unless a resultant force acts. | |
| 1. Motion, forces and energy | Core | Newton’s second law | F = ma for constant mass; resultant force = mass × acceleration. | |
| 1. Motion, forces and energy | Core | Newton’s third law | Forces between two objects are equal in size, opposite in direction, same type. | |
| 1. Motion, forces and energy | Core | Friction | Force opposing relative motion between surfaces. | |
| 1. Motion, forces and energy | Core | Drag (air resistance) | Opposes motion through a fluid; increases with speed. | |
| 1. Motion, forces and energy | Core | Terminal velocity | Constant speed when drag equals weight for falling objects. | |
| 1. Motion, forces and energy | Advanced | Linear momentum | p = mv; conserved in a closed system in the absence of external resultant force. | |
| 1. Motion, forces and energy | Core | Work done | W = Fs cos θ — energy transferred when a force moves an object. | |
| 1. Motion, forces and energy | Core | Kinetic energy | Energy due to motion: Ek = ½mv². | |
| 1. Motion, forces and energy | Core | Gravitational potential energy | Energy stored due to position in a field (near Earth: Ep = mgh). | |
| 1. Motion, forces and energy | Core | Elastic potential energy | Stored when a spring or material is stretched or compressed. | |
| 1. Motion, forces and energy | Advanced | Principle of conservation of energy | Total energy in a closed system is constant; energy is transferred between stores. | |
| 1. Motion, forces and energy | Core | Power | Rate of energy transfer or rate of doing work: P = E/t or P = W/t. | |
| 1. Motion, forces and energy | Core | Efficiency | Useful energy output ÷ total energy input × 100%. | |
| 2. Thermal physics | Essential | Temperature | Measure related to average kinetic energy of particles in a substance. | |
| 2. Thermal physics | Core | Kinetic particle model | Solids, liquids, gases differ in particle arrangement, movement and spacing. | |
| 2. Thermal physics | Core | Internal energy | Total kinetic and potential energy of particles in a substance. | |
| 2. Thermal physics | Core | Specific heat capacity | Energy to raise 1 kg of a substance by 1 °C. | |
| 2. Thermal physics | Core | Specific latent heat | Energy per kilogram for a change of state at constant temperature. | |
| 2. Thermal physics | Core | Melting / freezing | Solid ↔ liquid at melting point. | |
| 2. Thermal physics | Core | Boiling / condensing | Liquid ↔ gas at boiling point. | |
| 2. Thermal physics | Core | Evaporation | Liquid → gas below boiling point at the surface. | |
| 2. Thermal physics | Core | Conduction | Energy transfer through a material by particle vibration or free electron movement. | |
| 2. Thermal physics | Core | Convection | Energy transfer by movement of fluids (convection currents). | |
| 2. Thermal physics | Core | Radiation | Energy transfer by infrared and other EM waves; no medium required. | |
| 2. Thermal physics | Advanced | Thermal equilibrium | No net energy transfer between objects at the same temperature. | |
| 2. Thermal physics | Core | Thermal expansion | Most substances expand when heated (exceptions noted in syllabus). | |
| 3. Properties of waves (including light and sound) | Essential | Wave | Transfer of energy without permanent transfer of matter. | |
| 3. Properties of waves (including light and sound) | Core | Transverse wave | Oscillation perpendicular to energy transfer direction. | |
| 3. Properties of waves (including light and sound) | Core | Longitudinal wave | Oscillation parallel to energy transfer (e.g. sound). | |
| 3. Properties of waves (including light and sound) | Core | Amplitude | Maximum displacement from equilibrium. | |
| 3. Properties of waves (including light and sound) | Core | Frequency | Number of complete oscillations per second (Hz). | |
| 3. Properties of waves (including light and sound) | Core | Wavelength | Distance between two adjacent in-phase points on a wave. | |
| 3. Properties of waves (including light and sound) | Core | Period | Time for one complete oscillation; T = 1/f. | |
| 3. Properties of waves (including light and sound) | Core | Wave equation | v = fλ. | |
| 3. Properties of waves (including light and sound) | Core | Reflection | Wave bounces off a boundary; angle of incidence = angle of reflection. | |
| 3. Properties of waves (including light and sound) | Core | Refraction | Change in speed/direction when crossing a boundary between media. | |
| 3. Properties of waves (including light and sound) | Core | Diffraction | Spreading when waves pass through a gap or past an edge. | |
| 3. Properties of waves (including light and sound) | Advanced | Total internal reflection | Occurs when angle of incidence > critical angle; used in optical fibres. | |
| 3. Properties of waves (including light and sound) | Core | Echo | Reflection of sound; use for distance = speed × time ÷ 2. | |
| 3. Properties of waves (including light and sound) | Core | Electromagnetic spectrum | Family of transverse waves — radio, microwave, IR, visible, UV, X-ray, gamma. | |
| 4. Electricity and magnetism | Essential | Electric current | Rate of flow of charge; I = Q/t; measured in amperes. | |
| 4. Electricity and magnetism | Essential | Potential difference | Energy transferred per unit charge between two points; V = W/Q. | |
| 4. Electricity and magnetism | Core | Resistance | R = V/I; opposition to current; unit ohm (Ω). | |
| 4. Electricity and magnetism | Core | Ohm’s law | For a metallic conductor at constant temperature, I ∝ V. | |
| 4. Electricity and magnetism | Core | Series circuit | Single path — same current everywhere. | |
| 4. Electricity and magnetism | Core | Parallel circuit | Branches — same p.d. across each parallel branch. | |
| 4. Electricity and magnetism | Core | Electrical power | P = IV = I²R = V²/R. | |
| 4. Electricity and magnetism | Core | Electrical energy | E = Pt = IVt. | |
| 4. Electricity and magnetism | Core | Magnetic field | Region where magnetic materials experience a force. | |
| 4. Electricity and magnetism | Core | Electromagnet | Solenoid with iron core; field controlled by current. | |
| 4. Electricity and magnetism | Advanced | Electromagnetic induction | Induced e.m.f. when magnetic flux through a circuit changes (Faraday’s law idea at IGCSE level). | |
| 4. Electricity and magnetism | Core | Transformer | Changes alternating voltage using electromagnetic induction between coils. | |
| 4. Electricity and magnetism | Core | Motor effect | Force on current-carrying conductor in magnetic field. | |
| 4. Electricity and magnetism | Core | Generator effect | Induced e.m.f. when conductor cuts magnetic field lines. | |
| 5. Nuclear physics & space | Essential | Atom | Nucleus (protons + neutrons) surrounded by electrons. | |
| 5. Nuclear physics & space | Core | Proton number (atomic number) | Number of protons in nucleus; defines the element. | |
| 5. Nuclear physics & space | Core | Nucleon number (mass number) | Total protons + neutrons in nucleus. | |
| 5. Nuclear physics & space | Core | Isotope | Same proton number, different nucleon number. | |
| 5. Nuclear physics & space | Core | Alpha radiation | Helium nucleus; highly ionising; stopped by paper. | |
| 5. Nuclear physics & space | Core | Beta radiation | Fast electron from nucleus; moderate penetration. | |
| 5. Nuclear physics & space | Core | Gamma radiation | EM wave from nucleus; highly penetrating. | |
| 5. Nuclear physics & space | Core | Half-life | Average time for half the radioactive nuclei to decay. | |
| 5. Nuclear physics & space | Core | Activity | Decays per second (becquerel, Bq). | |
| 5. Nuclear physics & space | Advanced | Background radiation | Natural ionising radiation always present; subtract from readings in experiments. | |
| 5. Nuclear physics & space | Core | Fusion | Light nuclei join; releases energy (stars). | |
| 5. Nuclear physics & space | Core | Fission | Heavy nucleus splits; used in power and weapons. | |
| 5. Nuclear physics & space | Core | Solar system | Star, planets, moons, asteroids, comets — basic descriptive astronomy. | |
| 6. Pressure, moments & density | Essential | Density | Mass per unit volume: ρ = m/V. | |
| 6. Pressure, moments & density | Core | Pressure | Force per unit area: p = F/A. | |
| 6. Pressure, moments & density | Core | Liquid pressure | Increases with depth; depends on density and gravitational field. | |
| 6. Pressure, moments & density | Core | Atmospheric pressure | Due to weight of air; decreases with altitude. | |
| 6. Pressure, moments & density | Core | Moment of a force | Turning effect = force × perpendicular distance to pivot. | |
| 6. Pressure, moments & density | Core | Principle of moments | For equilibrium, sum of clockwise moments = sum of anticlockwise moments. | |
| 6. Pressure, moments & density | Advanced | Centre of mass | Point where weight appears to act; stability depends on base area and position. |
Pair this with our revision checklists, formula sheets hub and past paper finder.
Physics (0625) — Keywords & Key Terms FAQ
- What is on this Cambridge International IGCSE Physics keywords and key terms list?
- It is a topic-organised glossary of important physics terms with short, exam-style definitions aligned to Cambridge IGCSE Physics (0625) (0625). It is designed for “define”, “state”, “outline” and “explain” questions where precise vocabulary earns marks.
- How should I use this Physics glossary alongside past papers?
- Tick terms when you can recall them without reading the answer, then check your wording against mark schemes. Pair vocabulary practice with past papers for IGCSE Physics (0625) so you apply terms in context.
- Is this the same as a revision checklist or a formula sheet?
- No. Revision checklists help you track which syllabus topics you have covered and your confidence—separate pages on Tutopiya. Formula sheets summarise equations and quantitative relationships. This page is only a definitions and key-terms glossary for Physics. Quantitative relationships belong on formula sheets; this list emphasises language and concepts.
- Can I download this Physics keywords and key terms list for free?
- Yes. After a quick free sign-up you can download a UTF-8 CSV (opens in Excel or Google Sheets) or open a print-friendly page and save as PDF. Browsing the list on the page is free.
- Is this Physics list aligned to the 0625 specification?
- Topic groupings and wording follow Cambridge IGCSE Physics (0625) for Cambridge International IGCSE. Always confirm final learning objectives and any regional options in your official specification and recent examiner reports for your exam session.
- Why focus on definitions instead of full notes?
- Mark schemes reward correct technical terms and clear links between ideas. A compact glossary lets you drill the exact language examiners expect for Physics at IGCSE, separate from longer notes or topic trackers.