AQA GCSE Physics
Last Accessed
Recently visited lessons will appear here for quick access.Start exploring your first lesson today!
4.1 Energy
4.1.1 Energy changes in a system
4.1.1.1a - Energy Stores and System ChangesEnergy is a way of tracking changes in a system. In this lesson, you will practise describing where energy is stored before and after a change, without doing calculations. The key skill is to choose the system clearly, then describe which energy stores increase and which decrease.
4.1.1.1b - Energy Calculations and RedistributionEnergy calculations are a way of keeping accounts. When a system changes, energy may be transferred by heating, by a force doing work, or by electrical work when current flows. In this lesson, the aim is to calculate the size of those transfers and show, on one common scale, where the total energ...
4.1.1.2a - Kinetic EnergyKinetic energy is the energy associated with a moving object. This lesson is about one equation: how the mass and speed of an object determine its kinetic energy. For exams in 2026 and 2027, the kinetic-energy equation is supplied on the Physics Equations Sheet; the skill is to select and apply i...
4.1.1.2b - Elastic Potential Energy in a Stretched SpringA stretched spring stores energy in its elastic potential store. This lesson is about using the given elastic potential energy equation carefully: choosing the right values, using the right units, and checking that the spring has stayed within its limit of proportionality.
4.1.1.2c - Gravitational Potential EnergyWhen an object is raised above ground level, energy is transferred to its gravitational potential energy store. This lesson is about calculating that energy gained, using the equation supplied on the Physics Equations Sheet for exams in 2026 and 2027. In any calculation, the value of gravitationa...
4.1.1.3 - Specific Heat Capacity and Required Practical 1When a material is heated and its temperature rises, energy has been transferred to its thermal energy store. Specific heat capacity tells us how much energy a material needs for a given temperature rise. In this lesson you will use the given equation and learn the required practical method for d...
4.1.1.4 - Power and Work RatePower tells you how quickly energy is transferred or how quickly work is done. Two machines can transfer the same amount of energy, but the one that does it in less time has the greater power. Both power equations are supplied on the Physics Equations Sheet for exams in 2026 and 2027. You need to...
4.1.2 Conservation and dissipation of energy
4.1.2.1a - Conservation, Dissipation and Closed SystemsEnergy is useful because it lets us describe and predict changes, but energy is never used up in the strict physics sense. In this lesson, you will practise describing how energy is transferred usefully, stored, and dissipated in closed systems. The key exam habit is to say where the energy is st...
4.1.2.1b - Reducing Unwanted Energy Transfers and Required Practical 2Energy is not destroyed when a device, machine or building works, but not every transfer is useful. This lesson focuses on ways to reduce unwanted energy transfers, especially through lubrication and thermal insulation. It also teaches required practical activity 2, which is physics only: investi...
4.1.2.2 - EfficiencyEfficiency tells you how much of an input energy transfer becomes the output that was actually wanted. In this lesson you will use two equations supplied on the Physics Equations Sheet for exams in 2026 and 2027: one for energy transfers and one for power. You will also switch between decimal and...
4.1.3 National and global energy resources
4.1.3a - Energy Resources, Uses and ReliabilityEnergy resources are the sources humans use to transfer energy for useful purposes. In this lesson you will sort the main resources into renewable and non-renewable groups, compare their uses for transport, electricity generation and heating, and explain why some resources are more reliable than...
4.1.3b - Environmental Impact and Energy Resource DecisionsEnergy resources are not judged only by how much energy they can supply. Their use can affect the atmosphere, land, water, habitats, health, landscapes and future generations. In this lesson you will describe those environmental impacts, explain patterns in energy-resource use from data, and eval...
4.2 Electricity
4.2.1 Current, potential difference and resistance
4.2.1.1 - Standard circuit diagram symbolsCircuit diagrams are a compact way to show electrical circuits. They do not try to draw the real apparatus; instead, they use agreed symbols so that anyone can see which components are present and how they are connected. In this lesson you will learn how to recognise, draw and interpret the stand...
4.2.1.2 - Electrical Charge and CurrentElectric current is not the same thing as energy. It is a flow of electrical charge, and its size tells you how quickly charge is flowing. This lesson builds the circuit conditions needed for charge to flow, then uses the AQA relationship between charge flow, current and time.
4.2.1.3a - Current, Resistance and Potential DifferenceCurrent, resistance and potential difference are linked, so changing one can change the others. This lesson focuses on the relationship for a single component: how current depends on the component's resistance and the potential difference across it. You will also select and apply the equation V =...
4.2.1.3b - Required Practical 3 - Resistance in CircuitsResistance affects the current in a circuit for a given potential difference. In this required practical, you use circuit diagrams to build and check circuits, then use measurements of potential difference and current to calculate resistance. The investigation has two main parts: how the length o...
4.2.1.4a - Ohmic conductors, filament lamps and diodesDifferent circuit components do not all keep the same resistance. Some behave almost like a fixed opposition to current, but others change because they heat up or because their direction in the circuit matters. In this lesson you will compare the resistance behaviour of an ohmic conductor, a fila...
4.2.1.4b - Thermistors, LDRs And Sensing CircuitsSome resistors have a resistance that changes when their surroundings change. A thermistor responds to temperature, and an LDR responds to light intensity. In this lesson, you will use those changes to explain sensing circuits such as thermostats and lights that switch on when it gets dark.
4.2.1.4c - I-V Characteristics and Required Practical 4An I-V characteristic is a graph that shows how the current through a component changes as the potential difference across it changes. The shape of the graph is evidence: it tells you whether the component behaves linearly, whether its resistance changes, and how its properties match its function...
4.2.2 Series and parallel circuits
4.2.2a - Series Circuits and Equivalent ResistanceIn a series circuit, components are joined in one continuous route, so the same current passes through every component in that route. The supply potential difference is shared between the components, and series resistances add together. These three ideas let you construct, check and calculate dc...
4.2.2b - Parallel Circuits and Circuit CalculationsParallel circuits give electric charge more than one route through a circuit. That changes how potential difference, current and resistance behave, so the first job in any circuit question is to recognise the connections before doing any arithmetic. In this lesson, you will use parallel-circuit r...
4.2.3 Domestic uses and safety
4.2.3.1 - Direct and alternating potential differencePotential difference is often called voltage, and it is measured in volts, V. This lesson compares two ways a supply can provide potential difference: direct and alternating. You also need the key UK mains facts: mains electricity is ac, has a frequency of 50 Hz, and is about 230 V.
4.2.3.2 - Mains Electricity and Three-Core Cable SafetyMost electrical appliances are connected to the mains with a cable containing separate wires for live, neutral and earth. The colours and functions of these wires matter because the live wire can be dangerous even when an appliance is not working. This lesson focuses on what each wire does, what...
4.2.4 Energy transfers
4.2.4.1 - Electrical Power in CircuitsElectrical power tells you how quickly a circuit device transfers energy. In this lesson, the device might be a resistor, lamp, heater, motor, or any other component where energy changes happen. You need to connect power to the potential difference across the device, the current through it, and t...
4.2.4.2 - Energy Transfers in Everyday AppliancesEveryday electrical appliances are designed to transfer energy in useful ways. A fan transfers energy to the kinetic energy store of moving air, while a kettle transfers energy to the thermal energy store of water. In this lesson you will connect those transfers to power ratings, time, charge flo...
4.2.4.3 - The National GridThe National Grid transfers electrical power from power stations to consumers such as homes, schools, shops and factories. Its key idea is simple but important: use transformers and cables so that electricity can travel long distances with less energy wasted by heating the cables. In this lesson,...
4.2.5 Static electricity
4.2.5.1 - Static ChargeStatic electricity is the set of effects caused when electric charge builds up on an object instead of flowing steadily as a current. In this physics-only lesson, you will describe how rubbing insulating materials can produce static electricity and sparking. You will also explain the observations...
4.2.5.2 - Electric FieldsCharged objects can affect other charged objects even when they are not touching. This physics-only lesson explains that effect using the idea of an electric field: a region around a charged object where another charged object can experience a force. You will also learn the field pattern for an i...
4.3 Particle model of matter
4.3.1 Changes of state and the particle model
4.3.1.1a - Density Equation and Particle ModelDensity tells you how much mass is packed into a volume. In this lesson you will use the density equation, then use simple particle diagrams to explain why solids, liquids and gases usually have different densities. The full density required practical is a separate split; here the focus is the eq...
4.3.1.1b - Required Practical 5 - Measuring DensityDensity is found from two measurements: mass and volume. In this required practical you determine the density of a regular solid, an irregular solid and a liquid, choosing apparatus that measures each quantity accurately. The key skill is matching the volume method to the sample: dimensions for r...
4.3.1.2 - Changes of StateSubstances can change between solid, liquid and gas. In a change of state, the substance looks different and its particles are arranged or moving differently, but the substance itself has not become a new substance. The key exam idea is that mass is conserved when a substance changes state.
4.3.2 Internal energy and energy transfers
4.3.2.1 - Internal EnergyInternal energy is the energy stored inside a system by the particles that make up that system. At GCSE, the key idea is simple but easy to mix up: internal energy is about the particles inside the material, not just the movement of the whole object. Heating transfers energy to those particles, a...
4.3.2.2 - Temperature Changes and Specific Heat CapacityWhen energy is transferred to a material and its temperature increases, the size of the temperature rise is not random. It depends on how much energy is transferred, how much material is heated, and what the material is. Specific heat capacity is the property that lets you calculate these tempera...
4.3.2.3a - Specific Latent Heat and State-Change EnergyWhen a substance changes state, energy is transferred even though the temperature can stay the same. That energy is called latent heat because it changes the internal energy of the substance without showing up as a temperature rise. In this lesson you will learn what specific latent heat means, h...
4.3.2.3b - Heating and Cooling GraphsHeating and cooling graphs show how the temperature of a substance changes as energy is transferred to it or away from it. The most important skill is spotting the difference between a sloping section, where temperature changes, and a flat section, where a change of state happens at constant temp...
4.3.3 Particle model and pressure
4.3.3.1 - Particle Motion in GasesGas pressure can seem mysterious because the molecules are too small to see. The particle model gives a simple explanation: gas molecules move randomly, collide with surfaces, and those collisions create pressure. In this lesson, the key link is temperature, average kinetic energy, molecular moti...
4.3.3.2 - Pressure in GasesGas pressure is a physics-only part of the particle model topic. You will explain pressure using particles colliding with surfaces, then use the relationship between pressure and volume for a fixed mass of gas at constant temperature. The equation is given on the Physics equation sheet, but you n...
4.3.3.3 - Increasing the Pressure of a GasThis Physics-only, Higher-only lesson is about what happens when work is done on an enclosed gas. The key example is a bicycle pump: a force moves the piston, energy is transferred to the trapped air, and the air can get warmer. The important exam skill is explaining the chain of causes clearly.
4.4 Atomic structure
4.4.1 Atoms and isotopes
4.4.1.1 - The Structure of an AtomAtoms are much too small to see directly, but their structure explains many later ideas in atomic physics. In this lesson, the key picture is a tiny positive nucleus with negative electrons around it. The important exam details are the size scale, where the mass is, and how electrons can move bet...
4.4.1.2 - Mass Number, Atomic Number and IsotopesAtomic notation is a compact way to identify an atom or ion and count the particles in it. In this lesson, the key count is the number of protons, because that fixes which element the particle is. You will then use mass number and charge to work out neutrons and electrons, and to recognise isotopes.
4.4.1.3 - The Development of the Model of the AtomThe atomic model did not appear fully formed. Scientists changed it when new evidence made the old model unable to explain what had been observed. In this lesson, the important story is not memorising dates; it is explaining why each model replaced or improved the one before it.
4.4.2 Atoms and nuclear radiation
4.4.2.1a - Radioactive Decay, Activity and Radiation TypesRadioactive materials contain unstable nuclei. The key GCSE idea is that an unstable nucleus can give out nuclear radiation as it changes to become more stable, and this process is random. This lesson separates the actual decay rate of a source from the count-rate recorded by a detector, then ide...
4.4.2.1b - Properties and Uses of Nuclear RadiationAlpha, beta and gamma radiation behave differently as they travel through air and materials. This lesson is about those properties: penetration, range in air and ionising power. The exam skill is to use those properties to choose the best radiation source for a situation and to justify why the ot...
4.4.2.2 - Nuclear EquationsNuclear equations are a compact way to show what changes when an unstable nucleus emits radiation. In this lesson, the important skill is not memorising particular decay examples. It is balancing the mass numbers and atomic numbers when a single alpha or beta particle is emitted, and knowing that...
4.4.2.3a - Half-life and Random DecayRadioactive decay is random: you cannot predict exactly when one unstable nucleus will decay. In a large sample, though, the overall pattern is predictable enough to measure. Half-life describes that pattern by asking how long it takes for the number of undecayed nuclei, count rate, or activity t...
4.4.2.3b - Net Decline After Half-LivesThis is a Higher tier calculation skill. Once you know how many half-lives have passed, you can work out how much radioactive emission remains compared with the starting value. The safest exam habit is to keep the order of the ratio clear.
4.4.2.4 - Radioactive Contamination and IrradiationRadioactive sources can be useful, but they must be described carefully because two different hazards are easy to mix up. Irradiation means being exposed to nuclear radiation. Contamination means radioactive atoms are actually present where they are not wanted. This lesson keeps those ideas separ...
4.4.3 Hazards and uses of radioactive emissions and of background radiation
4.4.3.1 - Background RadiationBackground radiation is the small amount of ionising radiation that is around us all of the time. It comes from natural sources and from some man-made sources. In this physics-only lesson, the exam focus is where background radiation comes from, why dose can vary with occupation or location, and...
4.4.3.2 - Half-Lives and Isotope HazardsRadioactive isotopes do not all stay radioactive for similar lengths of time. Some have half-lives measured in seconds or hours, while others have half-lives measured in years, millions of years, or billions of years. In this physics-only lesson, you will use half-life data, often written in stan...
4.4.3.3 - Uses of Nuclear RadiationNuclear radiation can be harmful because it can ionise atoms in living cells, but that same ability can be useful in medicine when the dose is controlled. In this physics-only topic, the two GCSE uses are exploring internal organs and controlling or destroying unwanted tissue. The key exam skill...
4.4.4 Nuclear fission and fusion
4.4.4.1 - Nuclear FissionNuclear fission is a physics-only part of AQA GCSE Physics. It explains how a large unstable nucleus can split, why this releases energy, and how the released neutrons can lead to a chain reaction. The key exam skill is to describe or interpret the sequence in a fission diagram without adding rea...
4.4.4.2 - Nuclear FusionNuclear fusion is a physics-only idea about changes inside atomic nuclei. In fusion, two light nuclei join to form one heavier nucleus. The key exam point is that this nuclear change can release energy because some of the mass may be converted into the energy of radiation.
4.5 Forces
4.5.1 Forces and their interactions
4.5.1.1 - Scalar and Vector QuantitiesPhysics uses measured quantities to describe the world. Some quantities are complete when you know their size, such as 5 kg or 20 s. Others are incomplete unless you also give a direction, such as 12 N to the right.
4.5.1.2 - Contact and non-contact forcesA force is not just "something an object has". In GCSE Physics, a force is a push or pull on one object caused by its interaction with another object. This lesson is about naming those interactions, deciding whether contact is needed, and representing the forces with vectors.
4.5.1.3 - Gravity, Weight and MassMass and weight are closely linked, but they are not the same quantity. Mass tells you how much matter is in an object, while weight is the gravitational force acting on that object. In this lesson you will connect weight to gravitational field strength, calculate weight using W = mg, and describ...
4.5.1.4a - Resultant Forces in Straight LinesWhen more than one force acts on an object, their combined effect can be replaced by one single force. That single equivalent force is called the resultant force. In this lesson, all forces act along one straight line, so the calculation is about size and direction: add forces that pull or push t...
4.5.1.4b - Free-Body Diagrams and Resolving ForcesThis Higher Tier lesson is about representing forces clearly when they do not all act in one straight line. You will use free-body diagrams to show the forces acting on one isolated object or system, and scale vector diagrams to resolve forces, show equilibrium, and determine resultants. The key...
4.5.3 Forces and elasticity
4.5.3a - Elastic Deformation and Hooke's LawObjects can change shape when forces act on them. A spring can stretch, a sponge can compress, and a ruler can bend. This lesson is about the forces needed to deform a stationary object, the difference between elastic and inelastic deformation, and how Hooke's law links force, spring constant and...
4.5.3b - Elastic Potential Energy and Force-Extension DataForce-extension data lets you connect three ideas: how stiff a spring is, whether the spring is still behaving linearly, and how much energy is stored when it is stretched or compressed. The key is to read the graph or table first, then choose the relationship that matches the region of data you...
4.5.3c - Required Practical 6 - Force and ExtensionThis required practical investigates how the force applied to a spring affects its extension. The practical evidence should let you plot a force-extension graph, identify the linear region, calculate a spring constant, and judge whether the spring has gone beyond the limit of proportionality. The...
4.5.5 Pressure and pressure differences in fluids
4.5.5.1.1 - Pressure at a SurfacePressure tells you how concentrated a force is over an area. In this Physics-only lesson, the force comes from a fluid, which means a liquid or a gas. You will learn how fluid pressure produces a force normal to a surface, then use p = F / A with the correct SI units.
4.5.5.1.2 - Pressure in Liquids, Upthrust and SinkingThis AQA GCSE Physics point is physics-only and Higher Tier only. You will use the liquid-pressure equation, explain why pressure changes with depth and density, and connect pressure differences to upthrust. The key exam habit is to link the calculation to the physical picture: more liquid above...
4.5.5.2 - Atmospheric PressureThe atmosphere is a thin layer of air around the Earth. In this Physics-only lesson, you will use a simple model to explain atmospheric pressure: air molecules collide with surfaces, and the amount of air above a surface changes with height.
4.5.6 Forces and motion
4.5.6.1.1 - Distance and DisplacementDistance and displacement both describe motion, but they answer different questions. Distance asks how much ground was covered. Displacement asks where the object finished compared with where it started.
4.5.6.1.2 - SpeedSpeed tells you how fast something is moving. In physics, speed is a scalar quantity, so it has a size and a unit but no direction. This lesson covers typical speeds, measuring distance and time, and using s = vt for constant speed and average speed.
4.5.6.1.3 - VelocityVelocity tells you how fast an object is moving and the direction it is moving in. That one extra piece of information, the direction, is why velocity is treated differently from speed in GCSE Physics. In this lesson, the key skill is to decide whether a motion quantity is a scalar or a vector, t...
4.5.6.1.4 - Distance-Time GraphsDistance-time graphs show how the distance travelled by an object changes with time. For this specification point, the key skill is to treat the graph as data: read values from the axes, calculate speed from gradients, and, for Higher tier, use a tangent to find the speed of an accelerating objec...
4.5.6.1.5a - Acceleration and Velocity-Time GraphsAcceleration describes how quickly velocity changes. In this lesson, the main skill is to connect the equation for acceleration to the gradient of a velocity-time graph. If the line on the graph is steep, the velocity is changing quickly; if the line is horizontal, the velocity is not changing.
4.5.6.1.5b - Uniform Acceleration and Terminal VelocitySome motion graphs tell you more than just "speeding up" or "slowing down". In this lesson, you will use velocity-time graphs to find distance, apply the uniform-acceleration equation, and explain why a falling object can eventually move at a constant terminal velocity. The Higher Tier parts are...
4.5.6.2.1 - Newton's First LawNewton's First Law links force to changes in velocity. If the resultant force on an object is zero, the object does not suddenly choose to stop or start. A stationary object stays stationary, and a moving object keeps moving at the same speed in the same direction. Its velocity stays the same.
4.5.6.2.2a - Newton's Second Law and Resultant ForceNewton's Second Law links the resultant force on an object to the acceleration it produces. The equation is short, but the exam skill is careful: use the resultant force, use mass in kilograms, and give acceleration in metres per second squared. This lesson focuses on the core law, calculations,...
4.5.6.2.2b - Inertial Mass and Required Practical 7Newton's Second Law links resultant force, mass and acceleration. In this lesson you will use that link to understand inertial mass, then apply it to required practical 7: investigating how changing force or mass changes the acceleration of a trolley or toy car.
4.5.6.2.3 - Newton's Third LawNewton's Third Law describes what happens when two objects interact. The two objects exert forces on each other. Those forces are equal in size and opposite in direction, but they act on different objects. In this lesson you will identify third-law force pairs and use them correctly in simple equ...
4.5.6.3.1 - Stopping DistanceStopping distance is the total distance a vehicle travels from the moment a driver needs to stop to the moment the vehicle is stationary. It has two parts: the distance travelled while the driver reacts, and the distance travelled while the brakes slow the vehicle down. This lesson focuses on the...
4.5.6.3.2 - Reaction timeReaction time is the delay between noticing something and beginning to respond. In driving, it is the time between seeing a hazard and starting to brake. During that time the vehicle is still moving, so a longer reaction time means a longer thinking distance.
4.5.6.3.3 - Factors Affecting Braking DistanceBraking distance is the distance a vehicle travels after the brakes are applied until it stops. This lesson focuses on why that distance can increase because of road and weather conditions, or because the vehicle's brakes or tyres are in poor condition. It also uses typical stopping-distance data...
4.5.6.3.4 - Factors Affecting Braking Distance 2Braking is an energy transfer, not an energy disappearance. When a vehicle brakes, friction in the braking system does work that reduces the vehicle's kinetic energy and increases the temperature of the brakes. This lesson links that energy transfer to braking force, deceleration, danger, and Hig...
4.5.7 Momentum
4.5.7.1 - MomentumMomentum is a property of moving objects. In this Higher Tier lesson, you will define momentum, calculate it using p = mv, use the correct unit kg m/s, and keep track of direction when velocity is given as positive or negative.
4.5.7.2 - Conservation of MomentumMomentum can be used as a model for what happens during a collision. In this Higher Tier lesson, you will use the idea that total momentum is conserved in a closed system. The calculation questions in this specification point are Physics-only, but the core idea is the same throughout: count all t...
4.5.7.3 - Changes in MomentumIn this Higher Tier, physics-only lesson, you will use the idea that a force can change momentum. You will apply the equation F = m Δv / Δt, link it to F = ma, and explain how safety features reduce forces by increasing the time taken for a change in momentum.
4.6 Waves
4.6.1 Waves in air, fluids and solids
4.6.1.1 - Transverse and Longitudinal WavesA wave is a travelling disturbance. The disturbance can move through a material, such as water or air, while the material itself only moves locally. In this lesson, the key question is: how does the vibration of the medium compare with the direction the wave travels?
4.6.1.2a - Wave Properties and EquationsWaves transfer energy from one place to another. To describe a wave clearly, you need a small set of quantities: amplitude, wavelength, frequency, period and wave speed. This lesson is about what those quantities mean, how to read them from wave diagrams, and how to use the two AQA wave equations.
4.6.1.2b - Measuring Wave Speed and Required Practical 8Wave speed is not just a number from an equation; it is something you can measure with apparatus. In this lesson you will practise methods for measuring the speed of sound in air, the speed of ripples on water, and the speed of waves in a solid. You will also learn the required practical 8 method...
4.6.1.3a - Reflection of WavesWhen a wave reaches a boundary between two different materials, the wave does not simply "stop". Some wave energy may be reflected, some may be transmitted into the next material, and some may be absorbed by the material at the boundary. This Physics-only lesson focuses on those boundary effects...
4.6.1.3b - Required Practical 9 - Reflection and RefractionThis physics-only required practical investigates what happens when light meets a boundary between materials. You use a ray box to trace reflected and refracted rays, then measure angles with a protractor. The important practical skill is not just seeing the rays; it is setting up the normal corr...
4.6.1.4 - Sound WavesThis Higher-tier, physics-only lesson is about how sound waves can make solids vibrate. That idea explains both everyday examples, such as a window buzzing near a loudspeaker, and how the ear begins the process of hearing. The important limit is frequency: human hearing only works normally from 2...
4.6.1.5a - Ultrasound and Echo SoundingThis Physics-only Higher Tier lesson is about using high-frequency sound waves to detect structures that cannot be seen directly. You will explain how ultrasound is reflected, absorbed and transmitted at boundaries, how echo time gives distance, and how the same pulse-echo idea is used in medical...
4.6.1.5b - Seismic Waves and Earth StructureSeismic waves are waves produced by earthquakes. In this Higher tier Physics-only lesson, they are useful because they travel through parts of the Earth that cannot be seen or sampled directly. By comparing which seismic waves are detected, where they are detected, and how their speeds change, sc...
4.6.2 Electromagnetic waves
4.6.2.1 - The Electromagnetic SpectrumElectromagnetic waves are one family of transverse waves. They transfer energy from a source to an absorber, and they can travel through empty space. This lesson is about the shared features of the whole electromagnetic spectrum, the order of the groups, and why visible light is only the small pa...
4.6.2.2a - Refraction of Electromagnetic WavesThis Higher Tier lesson is about what happens when electromagnetic waves meet a boundary between substances. Different substances can absorb, transmit, reflect or refract waves differently, and the effect can depend on wavelength. The key idea is that refraction happens because the wave travels a...
4.6.2.2b - Required Practical 10 - Infrared Radiation and SurfacesThis required practical investigates how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface. The key skill is making a fair comparison: change only the surface, then measure radiation or temperature in a controlled way. The most common school...
4.6.2.3a - Radio Waves and Electromagnetic EmissionElectromagnetic waves transfer energy from a source to an absorber. This lesson is about how electromagnetic waves can be generated and absorbed, rather than about their applications. For Higher tier, you need radio waves from oscillating electrical circuits; for all students, you need the idea t...
4.6.2.3b - Ultraviolet, X-ray and Gamma HazardsUltraviolet waves, X-rays and gamma rays are high-frequency parts of the electromagnetic spectrum. They can transfer energy to human tissue in ways that cause harm, but the risk is not the same for every exposure. In this lesson, you will compare the type of radiation, the size of the dose, and t...
4.6.2.4 - Uses and Applications of Electromagnetic WavesElectromagnetic waves are useful because different parts of the spectrum interact with matter in different ways. In this lesson, the key skill is to match each type of electromagnetic wave to a practical application, then, for Higher tier, give a brief reason why that wave is suitable. The reason...
4.6.2.5 - LensesLenses form images by refracting light. In this Physics-only lesson you will use the AQA lens symbols, identify principal focus and focal length, construct ray diagrams for convex and concave lenses, and decide whether the image is real or virtual. You will also calculate magnification as a ratio...
4.6.2.6 - Visible LightVisible light is the part of the electromagnetic spectrum that human eyes can detect. In this physics-only lesson, the important idea is selective interaction: different wavelengths of visible light can be reflected, transmitted, scattered or absorbed by different materials. That explains why sur...
4.6.3 Black body radiation
4.6.3.1 - Emission and Absorption of Infrared RadiationInfrared radiation is electromagnetic radiation that can transfer energy between objects without the objects touching. In this physics-only lesson, the key idea is that every object emits and absorbs infrared radiation, even when it is cold. The hotter an object is, the more infrared radiation it...
4.6.3.2 - Perfect Black Bodies and Radiation BalanceThis physics-only lesson looks at radiation as an energy transfer that every object is involved in, not just objects that are glowing. The key idea is that temperature affects both the intensity of radiation emitted and the spread of wavelengths emitted. For Higher tier, you also need to explain...
4.7 Magnetism and electromagnetism
4.7.1 Permanent and induced magnetism, magnetic forces and fields
4.7.1.1 - Poles of a MagnetMagnets can push or pull other magnets even when they are not touching. This lesson is about the poles where those magnetic forces are strongest, how permanent magnets attract or repel, and how induced magnets behave differently from permanent magnets.
4.7.1.2 - Magnetic FieldsA magnetic field is how a magnet can exert a force without touching another object. In this lesson you will describe what a magnetic field is, use field lines to show its strength and direction, explain how to plot a bar magnet's field using a compass, and connect compass behaviour to the Earth's...
4.7.2 The motor effect
4.7.2.1a - Magnetic fields from currents and solenoidsAn electric current can create a magnetic field. In this lesson you will learn the field pattern around a straight current-carrying wire, how current and distance affect field strength, why a solenoid makes a stronger magnetic effect, and how an iron core turns a solenoid into an electromagnet.
4.7.2.1b - Electromagnetic DevicesA current in a wire does more than transfer electrical energy: it also produces a magnetic field around the wire. That magnetic effect can be strengthened by shaping the wire into a solenoid and by adding an iron core. In physics-only questions, you may also be given a diagram of a device such as...
4.7.2.2 - Fleming's Left-Hand RuleWhen a current-carrying conductor is placed in a magnetic field, the conductor and the magnet exert forces on each other. This is the motor effect. In this Higher Tier lesson, you will use Fleming's left-hand rule to link the directions of force, current and magnetic field, then apply the given e...
4.7.2.3 - Electric MotorsAn electric motor uses the motor effect to make something rotate. In this Higher Tier lesson, the important model is a coil of wire carrying a current in a magnetic field. The forces on the two sides of the coil act in opposite directions, giving a turning effect.
4.7.2.4 - LoudspeakersLoudspeakers and headphones turn an electrical signal into a sound wave. In AQA Physics this is a Physics-only, Higher Tier only example of the motor effect. The key idea is that variations in current cause variations in force, so a cone or diaphragm vibrates and makes pressure variations in the...
4.7.3 Induced potential, transformers and the National Grid
4.7.3.1 - Induced Potential and the Generator EffectWhen a conductor experiences a changing magnetic field, a potential difference can be induced across it. If the conductor is part of a complete circuit, that induced potential difference can drive an induced current. This Higher-tier physics-only lesson is about the generator effect: what causes...
4.7.3.2 - Uses of the generator effectThis Physics-only Higher-tier lesson is about how the generator effect is used in two devices: an alternator and a dynamo. Both involve motion in a magnetic field, but their output connections make their potential-difference graphs look different. By the end, you should be able to explain how eac...
4.7.3.3 - MicrophonesThis Physics-only Higher-tier lesson is about moving-coil microphones. A microphone uses the generator effect to convert pressure variations in a sound wave into variations in current in an electrical circuit. The exam skill is to explain that conversion as a clear chain of causes, not just to na...
4.7.3.4a - Transformer Structure and Turns RatioTransformers are Physics-only, Higher Tier content in AQA GCSE Physics. A transformer uses two coils on an iron core to change an alternating potential difference. In this lesson, the focus is the structure of a basic transformer and the ratio linking potential differences to the numbers of turns...
4.7.3.4b - Transformer Power, Current and TransmissionA transformer can change potential difference, but an ideal transformer does not create extra electrical power. This Higher-tier physics-only lesson uses that idea to calculate currents and to explain why the National Grid transmits electricity at high potential differences. The key pattern is si...
4.8 Space physics (physics only)
4.8.1 Solar system, orbital motion and satellites
4.8.1.1 - Our Solar System and Star FormationThe solar system is not the whole Universe. It is one small system inside the Milky Way galaxy, held together by the Sun's gravity. This physics-only lesson also explains the start of the Sun's life: dust and gas were pulled together by gravity until fusion reactions began and a stable balance fo...
4.8.1.2 - The Life Cycle of a StarStars are not fixed forever. A star forms, spends a long stable period shining, and then changes as its fuel changes. In this physics-only lesson, the route through the life cycle depends mainly on the star's mass: a star about the size of the Sun has a different ending from a star much more mass...
4.8.1.3 - Orbital Motion, Natural and Artificial SatellitesThis physics-only lesson explains how gravity keeps planets and satellites in orbit. You will compare planets, moons and artificial satellites, then use speed and velocity carefully to describe circular motion. Higher Tier sections explain why an orbiting object can have changing velocity but unc...
4.8.2 Red-shift and the expanding universe
4.8.2a - Red-shift and an Expanding UniverseRed-shift is one of the key observations behind the modern model of an expanding universe. In this physics-only lesson, you will learn what red-shift means, why light from a receding galaxy has a longer wavelength, and how the pattern of red-shift with distance provides evidence that space itself...
4.8.2b - Big Bang Theory, Dark Mass and Dark EnergyThe Big Bang theory is a scientific model about how the universe began and changed over time. In this physics-only lesson, the important point is not that scientists "saw" the Big Bang happen, but that observations of the universe support a model in which the universe was once much smaller, hotte...