Top 200 Vocabulary for JC 2 H2 Physics Syllabus | A-Level 9478 Electricity, Waves and Practical

JC 2 H2 Physics vocabulary for Singapore A-Level 9478: find 200 explained terms across mechanics, waves, heat, electric circuits, electromagnetism, modern physics and practical work. Each meaning tells you what the idea is and, where possible, which mistake to avoid in a real question.

For the 2027 H2 Physics examination, the syllabus is code 9478. It comprises four papers, including a practical examination requiring spreadsheet-based data processing. Words such as gradient, induced emf, stationary wave and half-life matter because they determine which mathematical model and physical explanation a student should apply.

Quick information for students and parents:

Exactly 200 distinct terms in 10 numbered sections, with on-page navigation.
Paper 1: multiple choice, 1 hour, 30 marks, 15%; Paper 2: structured, 2 hours, 75 marks, 30%.
Paper 3: longer structured, 2 hours, 75 marks, 35%; Paper 4: practical, 2 hours 30 minutes, 50 marks, 20%.
Practical includes planning, measurements, data presentation, analysis and spreadsheet processing.
Includes worked examples, an error checklist, a four-week plan, FAQs and original sources.

These 200 words are an independent educational selection aligned with published syllabus topics. They are not an official SEAB list of mandatory vocabulary, and the syllabus itself determines the examinable scope.

Find a Physics topic immediately

Top 200 Physics vocabulary words with meanings

1. Quantities, units and uncertainties

physical quantity — A measurable property described by a numerical magnitude and a unit, such as velocity in metres per second; name the property before calculating.
SI base unit — A standard unit from which derived units are constructed; in A-Level calculations, convert measurements consistently before substitution.
derived unit — A unit formed by multiplying or dividing base units, allowing dimensional checks of equations such as newtons or joules.
dimensional homogeneity — The requirement that quantities added or equated share compatible dimensions; it is an efficient check for wrong formulae.
scalar — A quantity with magnitude but no inherent direction, such as temperature or mass; a negative sign is not a vector arrow.
vector — A quantity with magnitude and direction, such as displacement or force, which must be combined using vector rules.
resultant — One vector representing the net effect of several vectors; components along different axes must be combined separately.
resolution of vectors — Splitting a vector into perpendicular components, often horizontal and vertical, to simplify equilibrium or motion.
absolute uncertainty — An estimated measurement uncertainty expressed in the same units as the measured value, such as ±0.02 s.
percentage uncertainty — Absolute uncertainty divided by the measurement magnitude and multiplied by 100%; useful for comparing relative reliability.
random error — Measurement variation that changes unpredictably among readings; repeat readings to estimate and reduce its effect on the mean.
systematic error — A consistent bias, for example incorrect instrument calibration, that repetition alone does not remove.
zero error — A nonzero instrument reading when the intended measured quantity is zero; correct the bias where justified.
precision — Closeness of repeated readings to one another; highly precise results may still be inaccurate.
accuracy — Closeness of a measurement to the true or accepted value; systematic errors can reduce it.
significant figures — Digits justified by input precision and calculation context; avoid claiming unrealistic certainty in a final answer.
order of magnitude — Approximate power-of-ten size of a quantity, used for quick estimates and plausibility checks.
gradient — Change in the vertical graph variable divided by change in the horizontal variable; units depend on both axes.
intercept — Value where a fitted graph crosses an axis; interpret it in the experimental context rather than assuming it is meaningful.
uncertainty propagation — Estimating how input measurement limits affect a calculated result; distinguish absolute from fractional uncertainties.

2. Forces, motion and equilibrium

distance — Total path length travelled, independent of direction; it cannot be negative for ordinary journeys.
displacement — Vector from initial to final position; it can be zero even after travelling a nonzero distance.
speed — Rate of change of distance, without direction; average speed need not equal average velocity magnitude.
velocity — Rate of change of displacement, including direction; the gradient of a displacement-time graph represents velocity.
acceleration — Rate of change of velocity; an object turning at constant speed can still be accelerating.
uniform acceleration — Acceleration constant in magnitude and direction, permitting standard equations of straight-line motion.
inertia — Property of matter that resists changes in velocity; inertial mass is distinct from the weight force.
Newton’s first law — An object maintains constant velocity unless acted on by a net external force; constant velocity includes rest.
Newton’s second law — Net force equals the rate of change of momentum, reducing to F=ma when mass remains constant.
Newton’s third law — Interaction forces are equal and opposite but act on different bodies; do not cancel them on one free-body diagram.
free-body diagram — Sketch showing only external forces acting on the selected object, with directions and labels.
normal contact force — Support force perpendicular to a surface, whose magnitude is not automatically equal to weight.
frictional force — Contact force opposing relative motion or tendency to slip; choose its direction from the proposed motion.
viscous drag — Resistive force experienced by an object moving through a fluid, often varying with speed.
upthrust — Upward buoyant force exerted by fluid pressure differences; compare with weight to judge whether an object floats.
Hooke’s law — Extension proportional to force within the proportional limit, written F=kx for an appropriate spring.
moment of force — Turning effect about a point equal to force times perpendicular distance from the pivot.
couple — Two equal, opposite, parallel forces at different lines of action that produce a pure turning effect.
translational equilibrium — Net force on a body equals zero; its velocity need not itself be zero.
rotational equilibrium — Net torque about a point equals zero; check this separately from net force.

3. Momentum, energy, gravitation and circles

linear momentum — Product of mass and velocity, p=mv, which is conserved in an isolated system.
impulse — Change in momentum produced by a force acting over a time interval, relevant to collisions and safety equipment.
conservation of momentum — Total vector momentum stays constant when resultant external impulse is zero.
elastic collision — Collision conserving total kinetic energy as well as momentum, under suitable idealisation.
inelastic collision — Collision in which kinetic energy changes while total momentum can remain conserved.
work done — Energy transferred by a force acting through displacement; only the component along displacement contributes.
kinetic energy — Energy associated with motion, ½mv² for speeds where classical mechanics applies.
gravitational potential energy — Energy associated with location in a gravitational field; its reference level must be specified.
power — Rate at which work is done or energy is transferred, measured in watts.
efficiency — Useful energy or power output divided by total input, usually expressed as a percentage.
conservative force — Force whose work depends on initial and final positions rather than the precise path.
gravitational field strength — Force per unit mass at a location, commonly expressed in N/kg or m/s².
gravitational potential — Work done per unit mass in bringing a small mass from infinity to a point, using a stated convention.
inverse-square law — Relationship in which force or field magnitude varies as one over separation squared for point sources.
orbital motion — Motion of a body under a force providing the centripetal acceleration necessary for its trajectory.
angular displacement — Angle through which an object turns, in radians, with a stated sense of rotation.
angular velocity — Rate of change of angular displacement, often expressed as radians per second.
centripetal acceleration — Acceleration directed towards the centre of circular motion, even when speed is constant.
centripetal force — Name for the resultant inward force causing circular acceleration, not an additional independent force.
period of rotation — Time for one complete revolution, related to angular speed by ω=2π/T.

4. Oscillations and wave basics

oscillation — Repeated motion about an equilibrium position; its amplitude and period describe the motion.
simple harmonic motion — Motion with acceleration proportional to and opposite displacement from equilibrium, written a=−ω²x.
amplitude — Maximum displacement from equilibrium, not the total peak-to-peak excursion.
angular frequency — Oscillation rate in radians per second, linked to frequency by ω=2πf.
phase — Position within the repeating cycle of an oscillation, usually expressed as an angle.
phase difference — Relative stage of two oscillations; it determines whether combined disturbances reinforce or cancel.
damping — Loss of oscillation energy to surroundings, often causing amplitude to decrease with time.
resonance — Large response when a driving frequency approaches a system’s natural frequency under suitable damping.
natural frequency — Frequency at which a system oscillates freely after a small disturbance.
restoring force — Force acting toward stable equilibrium and responsible for oscillatory behaviour.
wave — Travelling disturbance that transfers energy and information without a permanent transport of material overall.
transverse wave — Wave with oscillations perpendicular to the direction of propagation.
longitudinal wave — Wave with oscillations parallel to the direction of travel, such as sound in air.
wavelength — Spatial distance between equivalent points in consecutive wave cycles.
frequency — Number of complete cycles per second, measured in hertz.
wave speed — Propagation speed given by v=fλ in a uniform medium.
crest — Position of greatest positive displacement in a transverse wave picture.
trough — Position of greatest negative displacement in a transverse wave picture.
wavefront — Line or surface connecting points oscillating with the same phase.
polarisation — Restriction of transverse oscillations to a particular direction; longitudinal waves cannot be polarised this way.

5. Superposition, interference and optics

principle of superposition — Resultant displacement equals the algebraic sum of individual wave displacements at the same location and time.
coherence — Stable phase relationship between waves, essential for a sustained interference pattern.
constructive interference — Combined waves produce enhanced amplitude when their relative phases lead to reinforcement.
destructive interference — Combined waves have reduced or zero amplitude when relative phases oppose appropriately.
path difference — Difference in distances travelled by two waves before reaching an observation point.
double-slit interference — Two coherent openings producing alternating intensity fringes through varying path difference.
fringe spacing — Distance between adjacent bright or dark interference fringes, related to wavelength and geometry.
diffraction — Spreading of a wave after passing an aperture or edge; more pronounced when dimensions approach wavelength.
diffraction grating — Many closely spaced slits producing sharp maxima by interference at specific angles.
order of maximum — Integer identifying an interference maximum, with zero order at the central bright fringe.
stationary wave — Pattern formed by overlapping counter-propagating waves, with fixed nodes and antinodes.
node — Location of permanently zero displacement in an ideal standing wave.
antinode — Location of maximum possible oscillation amplitude in a standing wave.
fundamental frequency — Lowest allowed frequency for a vibrating system under stated boundary conditions.
harmonic — Allowed oscillation frequency that is an integer multiple of the fundamental where the system permits it.
refraction — Change in propagation direction when wave speed changes across a boundary.
refractive index — Ratio of light speed in vacuum to speed in a medium, also related to angles by Snell’s law.
critical angle — Incidence angle in a denser optical medium that gives a refracted angle of 90 degrees.
total internal reflection — Complete reflection for incidence above the critical angle from higher to lower refractive index.
electromagnetic spectrum — Continuous family of electromagnetic waves spanning radio to gamma radiation, all travelling at c in vacuum.

6. Thermal physics, gases and the first law

thermal equilibrium — State in which bodies in thermal contact no longer exchange net heat because of temperature differences.
temperature — Quantity linked to the thermal state of a system and direction of heat transfer.
internal energy — Total microscopic kinetic and potential energy of particles in a system.
heat transfer — Energy passing between systems because of a temperature difference, not a substance stored in a body.
specific heat capacity — Energy needed to raise a unit mass by one kelvin without a phase change.
specific latent heat — Energy per unit mass required for a phase change at constant temperature.
melting — Change from solid to liquid in which added energy can increase potential rather than average kinetic energy.
boiling — Vaporisation occurring throughout a liquid at a suitable pressure and temperature.
ideal gas — Simplified gas model obeying pV=nRT under its assumptions.
Boyle’s law — Pressure inversely proportional to volume for a fixed mass of gas at constant temperature.
Charles’s law — Volume proportional to absolute temperature for fixed gas amount at constant pressure.
pressure law — Pressure proportional to absolute temperature at fixed gas volume and amount.
molar gas constant — Universal constant R relating pressure, volume, amount and temperature for ideal gases.
Boltzmann constant — Constant k connecting the microscopic thermal energy scale to absolute temperature.
mean translational kinetic energy — Average energy of particle motion, 3kT/2 for a monatomic ideal gas.
root-mean-square speed — Square root of mean squared molecular speed, linked to temperature and particle mass.
kinetic theory of gases — Explanation of macroscopic gas behaviour through molecular collisions and motion.
molecular collision — Particle interaction transferring momentum; wall collisions generate gas pressure in the model.
first law of thermodynamics — Energy conservation linking heat added, work done and change in internal energy under a clear sign convention.
thermodynamic process — Change of system state for which variables such as pressure, volume and temperature may vary.

7. Electric fields and direct-current circuits

electric charge — Property responsible for electrical interactions, measured in coulombs and conserved in isolated systems.
electric field strength — Force per unit positive test charge at a point, E=F/q.
electric potential — Potential energy per unit positive charge relative to a specified reference.
potential difference — Electrical energy transferred per unit charge between two points in a circuit.
electric current — Rate of flow of electric charge, I=Q/t for constant flow.
drift velocity — Average directed speed of charge carriers through a conducting material.
resistance — Ratio of potential difference across a component to current through it at that operating condition.
resistivity — Material property linking resistance to geometry, R=ρL/A for a uniform conductor.
Ohm’s law — Current proportional to potential difference for a conductor at constant physical conditions.
electromotive force — Energy supplied per unit charge by a source around the complete circuit.
internal resistance — Resistance within a power source that causes terminal voltage to fall as current rises.
terminal potential difference — Voltage measured across source terminals during operation, different from emf under load.
series circuit — Single current path through connected components, with potential differences adding across the path.
parallel circuit — Separate branches sharing the same potential difference between their common junctions.
Kirchhoff’s current law — Charge conservation implies current entering a junction equals current leaving it.
Kirchhoff’s voltage law — Energy conservation implies algebraic sum of potential differences round a closed loop is zero.
potential divider — Series resistance arrangement producing a chosen fraction of supply voltage.
thermistor — Temperature-dependent resistor useful as a sensor in a sensing circuit.
light-dependent resistor — Component whose resistance varies with illumination, permitting light-sensitive circuits.
electric power — Rate of electrical energy transfer, calculable as IV and other equivalent expressions under suitable conditions.

8. Magnetism, induction, capacitors and alternating current

magnetic flux density — Field quantity B determining the force on moving charges and currents, measured in tesla.
magnetic force on charge — Force qvBsinθ acting on a moving charge in a magnetic field, perpendicular to velocity and field.
magnetic force on conductor — Force on a current-carrying segment placed in an external magnetic field.
magnetic flux — Surface integral of magnetic field through an area, simplified to BAcosθ for uniform fields.
magnetic flux linkage — Total flux linked by turns of a coil, commonly NΦ for equivalent turns.
Faraday’s law — Induced emf equals the rate of change of magnetic flux linkage with a negative sign indicating opposition.
Lenz’s law — Direction of induced current opposes the change in magnetic flux that produces it.
electromagnetic induction — Production of an emf when flux linkage through a circuit changes.
alternating current — Electric current reversing direction periodically, generally with a varying magnitude.
peak value — Largest magnitude reached during an alternating waveform’s cycle.
root-mean-square current — Direct-current equivalent giving the same mean resistive heating effect.
transformer — Device using time-varying magnetic flux to change alternating voltage through coupled coils.
primary coil — Transformer winding connected to the input electrical source.
secondary coil — Transformer winding supplying the output, with voltage related to turns under ideal assumptions.
capacitor — Component storing equal and opposite charge on conductors separated by an insulator.
capacitance — Ratio of stored charge to potential difference, C=Q/V.
dielectric — Insulating material between capacitor plates that influences capacitance.
capacitor discharge — Release of charge from a capacitor, commonly following an exponential time course in an RC circuit.
time constant — Characteristic time RC for exponential charging or discharging behaviour.
capacitor energy — Electrostatic energy stored by a capacitor, equal to ½CV².

9. Atomic, quantum and nuclear physics

photon — Quantum of electromagnetic radiation with energy hf.
Planck constant — Constant h linking photon energy and frequency, fundamental to quantum descriptions.
photoelectric effect — Emission of electrons from a metal surface when incident photons have sufficient energy.
work function — Minimum energy required to free an electron from a given material surface.
threshold frequency — Minimum photon frequency required to cause photoelectron emission.
stopping potential — Retarding potential just sufficient to prevent the most energetic photoelectrons reaching the collector.
de Broglie wavelength — Matter-wave wavelength associated with momentum, λ=h/p.
electron diffraction — Wave-like scattering pattern of electrons, providing evidence for matter waves.
energy level — Allowed discrete energy state in a quantum system such as an atom.
excitation — Transition of an atom or electron to a higher-energy state by absorbing energy.
emission line — Discrete wavelength produced when an excited system drops to a lower energy state.
absorption spectrum — Wavelength pattern indicating radiation removed by matter through allowed transitions.
atomic nucleus — Dense central region containing protons and neutrons.
nucleon number — Number of protons plus neutrons in an atomic nucleus.
isotope — Atom with the same proton number but a different neutron number.
mass defect — Difference between separate constituent masses and the bound nucleus mass.
binding energy — Energy needed to separate a nucleus into free nucleons, equivalent to mass defect times c².
radioactive decay — Spontaneous probabilistic transformation of unstable nuclei with emitted particles or radiation.
half-life — Time needed for activity or the number of undecayed nuclei in a large sample to halve.
nuclear fission — Splitting a heavy nucleus into lighter nuclei, releasing energy when total binding changes.

10. Experimental technique, spreadsheets and examination language

calibration — Checking instrument readings against standards and adjusting or correcting known systematic bias.
control variable — Quantity kept fixed so that an observed relationship can be attributed more confidently to the intended change.
independent variable — Quantity deliberately changed or assigned along the horizontal graph axis when appropriate.
dependent variable — Measured quantity responding to the deliberately changed input.
data logging — Automatic recording of measurements over time using suitable sensors and software.
spreadsheet formula — Expression in a spreadsheet cell used to process measured data reproducibly.
best-fit line — Straight line chosen to represent the trend in plotted data rather than joining every scattered point.
error bar — Graphical representation of measurement uncertainty or variability, with its meaning stated.
anomalous point — Reading departing unusually from the pattern and requiring investigation rather than automatic deletion.
repeat measurement — Further reading taken under similar conditions to assess consistency and detect unusual variation.
systematic correction — Adjustment of results for a justified known instrument bias, with the original method documented.
percentage difference — Difference relative to a stated reference value, not interchangeable with percentage uncertainty.
gradient uncertainty — Estimated possible variation in gradient consistent with plotted data and their uncertainties.
linearity — Relationship in which a suitable plot follows an approximately straight line under specified conditions.
experimental limitation — Feature of the method that restricts accuracy, precision, validity or generalisability.
practical improvement — Specific justified change addressing an identified source of uncertainty or bias.
deduce — Reach an answer using the given information and a valid chain of physical reasoning.
describe — State the important observable characteristics or sequence without assuming that explanation was requested.
explain — Give a physical mechanism or reason supporting a result rather than only restating the observation.
evaluate — Assess a claim or method using evidence, limitations and an explicitly justified judgement.

How to turn Physics vocabulary into correct reasoning

A Physics problem normally contains three layers: a description of a system, a model that is suitable for that system, and a mathematical calculation or prediction. Students can remember the equation but still fail when the terms in the first layer are misunderstood. For example, a velocity-time graph’s gradient gives acceleration and its signed area gives displacement. Speed and distance cannot always be substituted because they discard direction. Naming the correct quantity is the first step of solving the question.

The second layer is the model. In Mechanics, the conservation of linear momentum requires zero resultant external impulse for the system being considered. In circular motion, centripetal force is the name given to the net inward force, not an extra arrow to add to gravity or tension. In electrical circuits, a source’s emf and its terminal potential difference may differ because of internal resistance. State the assumption before using the relation.

Finally, translate the number back into the situation. A negative acceleration may simply mean acceleration points against the chosen positive axis. It need not mean an object is slowing down. A negative voltage similarly depends on your declared reference and direction. Physics vocabulary allows a reader to explain everyday engineering, medical imaging, electricity consumption and scientific discoveries with greater precision.

Three worked Physics examples

Example 1: constant speed does not mean zero acceleration

A cyclist travels around a roundabout at constant speed 6 m/s along a circular path of radius 12 m. The centripetal acceleration is v²/r=36/12=3 m/s² towards the centre. Velocity is changing direction even though speed is constant. The force causing that acceleration may be friction between the tyres and road; it is not a new force separate from friction.

Example 2: internal resistance changes terminal voltage

A battery has emf 6.0 V and internal resistance 0.50 Ω. If the circuit current is 2.0 A, the terminal potential difference while delivering current is V=ε−Ir=6.0−1.0=5.0 V. The lost volt is associated with energy dissipated inside the source. The quantities emf, current and terminal potential difference answer different questions, so they must not be used interchangeably.

Example 3: a half-life is not a fixed number of decays

An idealised sample starts with 800 unstable nuclei and has a half-life of four hours. After eight hours, two half-lives have elapsed and the expected remaining number is 800×(1/2)²=200. The population decays statistically; it does not mean precisely half of a tiny set of nuclei must disappear at the clock’s four-hour mark. This distinction separates an exponential model from individual unpredictable decays.

Confusions students should correct early

Common confusion	Better habit
Distance and displacement	Use path length for distance and start-to-finish directed change for displacement.
Mass and weight	Mass is measured in kg; weight is a force measured in N.
Centripetal force and an additional force	Identify the real forces producing the net inward force.
Acceleration and slowing down	Compare the signs of velocity and acceleration in the chosen direction.
Emf and terminal voltage	Account for internal resistance when current flows.
Accuracy and precision	Repetition reduces random variability but does not correct a consistent bias.
Constructive interference and larger frequency	Interference changes amplitude through superposition, not the source frequency.

Paper 4: spreadsheet and practical preparation

H2 Physics 9478 practical work includes two sections. Candidates are given 1 hour 15 minutes of apparatus access in each section, with work covering planning and experimental skill. The syllabus specifically requires processing and analysing some data using spreadsheet software. A good revision routine therefore includes entering raw results in cells, writing a correct formula once, copying it with the right relative or fixed references, creating an appropriate scatter plot and interpreting its gradient and intercept.

Keep an uncertainty audit. If your ruler has a zero error, repeating the same wrong reading ten times will not remove the bias. If the line of best fit does not pass near the origin, investigate whether that intercept is expected physically or reveals a systematic effect. Describe each source of uncertainty specifically and propose improvements that address the identified limitation. A general statement such as “use a better apparatus” rarely explains enough.

Four-week vocabulary-to-exam plan

Week 1 — measurements and mechanics: words 1–60. Solve graph and circular-motion questions, and write units and assumptions beside each calculation.
Week 2 — waves and thermal physics: words 61–120. Draw phase differences, standing-wave patterns and thermal-process diagrams, then explain the physical mechanism.
Week 3 — electricity, magnetism and modern physics: words 121–180. Practise circuit reasoning, induction direction, capacitor changes and nuclear models.
Week 4 — experiment and integration: words 181–200. Work on spreadsheet interpretation, practical uncertainty, and cross-topic timed questions; note every mistake in an error log.

Four weeks can organise revision but cannot replace strong JC1 foundations. If vector components, algebra and measurement units remain weak, repair those first. Revise with the particular syllabus edition for your examination year.

Frequently asked questions about JC2 Physics

What is the 2027 H2 Physics code?

9478 for Singapore-Cambridge GCE A-Level H2 Physics. Older resources may refer to 9749, so check that topics and paper demands match the current syllabus.

Does JC2 H2 Physics have a practical examination?

Yes. Paper 4 is worth 20% and lasts two hours 30 minutes. Its scope includes planning, measurement, data and uncertainty, and analysis using spreadsheet software.

Does Paper 3 offer a question choice?

Yes. It includes compulsory Section A questions worth 55 marks and a Section B choice of one out of two 20-mark questions.

Are Waves and Thermal Physics part of H2 rather than H1?

The revised curriculum overview states that Waves and Thermal Physics are omitted from the reduced H1 Physics scope, while they are included at H2. Use the correct level.

Is Physics just memorising equations?

No. Derivations, modelling assumptions, diagrams, direction and interpretation matter. The data-and-formulae sheets do not replace knowing what each quantity represents.

How can parents support revision without knowing advanced Physics?

Ask the student to explain the difference between two easily confused terms, draw a diagram, name assumptions and show how the final number answers the real question.

Official references and related eduKate reading

Syllabus checked 7 November 2026. This is independent educational material, not an official MOE or SEAB publication. Always confirm the examination-year syllabus before relying on paper details.