IGCSE Physics syllabus checklist

CoreEvery candidate

• 1.1Describe the use of rulers and measuring cylinders to find a length or a volume.
• 1.1Describe how to measure a variety of time intervals using clocks and digital timers.
• 1.1Determine an average value for a small distance and for a short interval of time by measuring multiples (including the period of oscillation of a pendulum).
• 1.2Define speed as distance travelled per unit time; recall and use the equation v = s/t.
• 1.2Define velocity as speed in a given direction.
• 1.2Recall and use the equation average speed = total distance travelled / total time taken.
• 1.2Sketch, plot and interpret distance–time and speed–time graphs.
• 1.2Determine, qualitatively, from given data or the shape of a distance–time or speed–time graph when an object is at rest, moving with constant speed, accelerating or decelerating.
• 1.2Calculate speed from the gradient of a straight-line section of a distance–time graph.
• 1.2Calculate the area under a speed–time graph to determine the distance travelled for motion with constant speed or constant acceleration.
• 1.2State that the acceleration of free fall g for an object near to the surface of the Earth is approximately constant and is approximately 9.8 m/s².
• 1.3State that mass is a measure of the quantity of matter in an object at rest relative to the observer.
• 1.3State that weight is a gravitational force on an object that has mass.
• 1.3Define gravitational field strength as force per unit mass; recall and use the equation g = W/m, and know that this is equivalent to the acceleration of free fall.
• 1.3Know that weights (and masses) may be compared using a balance.
• 1.4Define density as mass per unit volume; recall and use the equation ρ = m/V.
• 1.4Describe how to determine the density of a liquid, of a regularly shaped solid and of an irregularly shaped solid which sinks in a liquid (volume by displacement), including appropriate calculations.
• 1.4Determine whether an object floats based on density data.

SupplementExtended candidates only

• 1.1Understand that a scalar quantity has magnitude (size) only and that a vector quantity has magnitude and direction.
• 1.1Know that distance, speed, time, mass, energy and temperature are scalars, and that force, weight, velocity, acceleration, momentum, electric field strength and gravitational field strength are vectors.
• 1.1Determine, by calculation or graphically, the resultant of two vectors at right angles, limited to forces or velocities only.
• 1.2Define acceleration as change in velocity per unit time; recall and use the equation a = Δv/Δt.
• 1.2Determine from given data or the shape of a speed–time graph when an object is moving with constant acceleration or changing acceleration.
• 1.2Calculate acceleration from the gradient of a speed–time graph.
• 1.2Know that a deceleration is a negative acceleration and use this in calculations.
• 1.2Describe the motion of objects falling in a uniform gravitational field with and without air resistance, including reference to terminal velocity.
• 1.3Describe, and use the concept of, weight as the effect of a gravitational field on a mass.
• 1.4Determine whether one liquid will float on another liquid based on density data, given that the liquids do not mix.

CoreEvery candidate

• 1.5.1Know that forces may produce changes in the size and shape of an object.
• 1.5.1Sketch, plot and interpret load–extension graphs for an elastic solid and describe the associated experimental procedures.
• 1.5.1Determine the resultant of two or more forces acting along the same straight line.
• 1.5.1Know that an object either remains at rest or continues in a straight line at constant speed unless acted on by a resultant force.
• 1.5.1State that a resultant force may change the velocity of an object by changing its direction of motion or its speed.
• 1.5.1Describe solid friction as the force between two surfaces that may impede motion and produce heating.
• 1.5.1Know that friction (drag) acts on an object moving through a liquid.
• 1.5.1Know that friction (drag) acts on an object moving through a gas (e.g. air resistance).
• 1.5.2Describe the moment of a force as a measure of its turning effect and give everyday examples.
• 1.5.2Define the moment of a force as moment = force × perpendicular distance from the pivot; recall and use this equation.
• 1.5.2Apply the principle of moments to situations with one force each side of the pivot, including balancing of a beam.
• 1.5.2State that, when there is no resultant force and no resultant moment, an object is in equilibrium.
• 1.5.3State what is meant by centre of gravity.
• 1.5.3Describe an experiment to determine the position of the centre of gravity of an irregularly shaped plane lamina.
• 1.5.3Describe, qualitatively, the effect of the position of the centre of gravity on the stability of simple objects.

SupplementExtended candidates only

• 1.5.1Define the spring constant as force per unit extension; recall and use the equation k = F/x.
• 1.5.1Define and use the term limit of proportionality for a load–extension graph and identify this point on the graph (an understanding of the elastic limit is not required).
• 1.5.1Recall and use the equation F = ma and know that the force and the acceleration are in the same direction.
• 1.5.1Describe, qualitatively, motion in a circular path due to a force perpendicular to the motion: speed increases if force increases (mass and radius constant); radius decreases if force increases (mass and speed constant); an increased mass requires an increased force to keep speed and radius constant.
• 1.5.2Apply the principle of moments to other situations, including those with more than one force each side of the pivot.
• 1.5.2Describe an experiment to demonstrate that there is no resultant moment on an object in equilibrium.

SupplementExtended candidates only

• 1.6Define momentum as mass × velocity; recall and use the equation p = mv.
• 1.6Define impulse as force × time for which the force acts; recall and use the equation impulse = FΔt = Δ(mv).
• 1.6Apply the principle of the conservation of momentum to solve simple problems in one dimension.
• 1.6Define resultant force as the change in momentum per unit time; recall and use the equation F = Δp/Δt.

CoreEvery candidate

• 1.7.1State that energy may be stored as kinetic, gravitational potential, chemical, elastic (strain), nuclear, electrostatic and internal (thermal).
• 1.7.1Describe how energy is transferred between stores during events and processes, including examples of transfer by forces (mechanical work done), electrical currents (electrical work done), heating, and by electromagnetic, sound and other waves.
• 1.7.1Know the principle of the conservation of energy and apply this principle to simple examples including the interpretation of simple flow diagrams.
• 1.7.2Understand that mechanical or electrical work done is equal to the energy transferred.
• 1.7.2Recall and use the equation for mechanical working W = Fd = ΔE.
• 1.7.3Describe how useful energy may be obtained, or electrical power generated, from chemical energy stored in fossil fuels, chemical energy stored in biofuels, water (waves, tides and hydroelectric dams), geothermal resources, nuclear fuel, light from the Sun (solar cells), and infrared and other electromagnetic waves from the Sun (solar panels and wind energy) — including references to a boiler, turbine and generator where they are used.
• 1.7.3Describe advantages and disadvantages of each method in terms of renewability, availability, reliability, scale and environmental impact.
• 1.7.3Understand, qualitatively, the concept of efficiency of energy transfer.
• 1.7.4Define power as work done per unit time and also as energy transferred per unit time; recall and use the equations P = W/t and P = ΔE/t.

SupplementExtended candidates only

• 1.7.1Recall and use the equation for kinetic energy Ek = ½mv².
• 1.7.1Recall and use the equation for the change in gravitational potential energy ΔEp = mgΔh.
• 1.7.1Know the principle of the conservation of energy and apply this principle to complex examples involving multiple stages, including the interpretation of Sankey diagrams.
• 1.7.3Know that radiation from the Sun is the main source of energy for all our energy resources except geothermal, nuclear and tidal.
• 1.7.3Know that energy is released by nuclear fusion in the Sun.
• 1.7.3Know that research is being carried out to investigate how energy released by nuclear fusion can be used to produce electrical energy on a large scale.
• 1.7.3Define efficiency as (useful energy output ÷ total energy input) × 100% and (useful power output ÷ total power input) × 100%; recall and use these equations.

CoreEvery candidate

• 1.8Define pressure as force per unit area; recall and use the equation p = F/A.
• 1.8Describe how pressure varies with force and area in the context of everyday examples.
• 1.8Describe, qualitatively, how the pressure beneath the surface of a liquid changes with depth and density of the liquid.

SupplementExtended candidates only

• 1.8Recall and use the equation for the change in pressure beneath the surface of a liquid Δp = ρgΔh.

CoreEvery candidate

• 2.1.1Know the distinguishing properties of solids, liquids and gases.
• 2.1.1Know the terms for the changes in state between solids, liquids and gases (gas to solid and solid to gas transfers are not required).
• 2.1.2Describe the particle structure of solids, liquids and gases in terms of the arrangement, separation and motion of the particles, and represent these states using simple particle diagrams.
• 2.1.2Describe the relationship between the motion of particles and temperature, including the idea that there is a lowest possible temperature (−273 °C), known as absolute zero, where the particles have least kinetic energy.
• 2.1.2Describe the pressure and the changes in pressure of a gas in terms of the motion of its particles and their collisions with a surface.
• 2.1.2Know that the random motion of microscopic particles in a suspension is evidence for the kinetic particle model of matter.
• 2.1.2Describe and explain this motion (Brownian motion) in terms of random collisions between the microscopic particles in a suspension and the particles of the gas or liquid.
• 2.1.3Describe qualitatively, in terms of particles, the effect on the pressure of a fixed mass of gas of a change of temperature at constant volume and of a change of volume at constant temperature.
• 2.1.3Convert temperatures between kelvin and degrees Celsius; recall and use T (in K) = θ (in °C) + 273.
• 2.2.1Describe, qualitatively, the thermal expansion of solids, liquids and gases at constant pressure.
• 2.2.1Describe some of the everyday applications and consequences of thermal expansion.
• 2.2.2Know that a rise in the temperature of an object increases its internal energy.
• 2.2.3Describe melting and boiling in terms of energy input without a change in temperature.
• 2.2.3Know the melting and boiling temperatures of water at standard atmospheric pressure.
• 2.2.3Describe condensation and solidification in terms of particles.
• 2.2.3Describe evaporation in terms of the escape of more-energetic particles from the surface of a liquid.
• 2.2.3Know that evaporation causes cooling of a liquid.
• 2.3.1Describe experiments to demonstrate the properties of good thermal conductors and bad thermal conductors (thermal insulators).
• 2.3.2Know that convection is an important method of thermal energy transfer in liquids and gases.
• 2.3.2Explain convection in liquids and gases in terms of density changes and describe experiments to illustrate convection.
• 2.3.3Know that thermal radiation is infrared radiation and that all objects emit this radiation.
• 2.3.3Know that thermal energy transfer by thermal radiation does not require a medium.
• 2.3.3Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of infrared radiation.
• 2.3.4Explain some of the basic everyday applications and consequences of conduction, convection and radiation, including heating objects such as kitchen pans and heating a room by convection.

SupplementExtended candidates only

• 2.1.2Know that the forces and distances between particles (atoms, molecules, ions and electrons) and the motion of the particles affect the properties of solids, liquids and gases.
• 2.1.2Describe the pressure and the changes in pressure of a gas in terms of the forces exerted by particles colliding with surfaces, creating a force per unit area.
• 2.1.2Know that microscopic particles may be moved by collisions with light fast-moving molecules and correctly use the terms atoms or molecules as distinct from microscopic particles.
• 2.1.3Recall and use the equation pV = constant for a fixed mass of gas at constant temperature, including a graphical representation of this relationship.
• 2.2.1Explain, in terms of the motion and arrangement of particles, the relative order of magnitudes of the expansion of solids, liquids and gases as their temperatures rise.
• 2.2.2Describe an increase in temperature of an object in terms of an increase in the average kinetic energies of all of the particles in the object.
• 2.2.2Define specific heat capacity as the energy required per unit mass per unit temperature increase; recall and use the equation c = ΔE/(mΔθ).
• 2.2.2Describe experiments to measure the specific heat capacity of a solid and a liquid.
• 2.2.3Describe the differences between boiling and evaporation.
• 2.2.3Describe how temperature, surface area and air movement over the surface affect evaporation.
• 2.2.3Explain the cooling of an object in contact with an evaporating liquid.
• 2.3.1Describe thermal conduction in all solids in terms of atomic or molecular lattice vibrations and also in terms of the movement of free (delocalised) electrons in metallic conductors.
• 2.3.1Describe, in terms of particles, why thermal conduction is bad in gases and most liquids.
• 2.3.1Know that there are many solids that conduct thermal energy better than thermal insulators but do so less well than good thermal conductors.
• 2.3.3Know that for an object to be at a constant temperature it needs to transfer energy away from the object at the same rate that it receives energy.
• 2.3.3Know what happens to an object if the rate at which it receives energy is less or more than the rate at which it transfers energy away from the object.
• 2.3.3Know how the temperature of the Earth is affected by factors controlling the balance between incoming radiation and radiation emitted from the Earth’s surface.
• 2.3.3Describe experiments to distinguish between good and bad emitters of infrared radiation, and between good and bad absorbers of infrared radiation.
• 2.3.3Describe how the rate of emission of radiation depends on the surface temperature and the surface area of an object.
• 2.3.4Explain some of the more complex applications and consequences of conduction, convection and radiation where more than one type of thermal energy transfer is significant, including a fire burning wood or coal and a radiator in a car.

CoreEvery candidate

• 3.1Know that waves transfer energy without transferring matter.
• 3.1Describe what is meant by wave motion as illustrated by vibrations in ropes and springs, and by experiments using water waves.
• 3.1Describe the features of a wave in terms of wavefront, wavelength, frequency, crest (peak), trough, amplitude and wave speed.
• 3.1Recall and use the equation for wave speed v = fλ.
• 3.1Know that for a transverse wave the direction of vibration is at right angles to the direction of propagation, and understand that electromagnetic radiation, water waves and seismic S-waves (secondary) can be modelled as transverse.
• 3.1Know that for a longitudinal wave the direction of vibration is parallel to the direction of propagation, and understand that sound waves and seismic P-waves (primary) can be modelled as longitudinal.
• 3.1Describe how waves can undergo reflection at a plane surface, refraction due to a change of speed, and diffraction through a narrow gap.
• 3.1Describe the use of a ripple tank to show reflection at a plane surface, refraction due to a change in speed caused by a change in depth, diffraction due to a gap, and diffraction due to an edge.
• 3.4Describe the production of sound by vibrating sources.
• 3.4Describe the longitudinal nature of sound waves.
• 3.4State the approximate range of frequencies audible to humans as 20 Hz to 20 000 Hz.
• 3.4Know that a medium is needed to transmit sound waves.
• 3.4Know that the speed of sound in air is approximately 330–350 m/s.
• 3.4Describe a method involving a measurement of distance and time for determining the speed of sound in air.
• 3.4Describe how changes in amplitude and frequency affect the loudness and pitch of sound waves.
• 3.4Describe an echo as the reflection of sound waves.
• 3.4Define ultrasound as sound with a frequency higher than 20 kHz.

SupplementExtended candidates only

• 3.1Describe how wavelength and gap size affect diffraction through a gap.
• 3.1Describe how wavelength affects diffraction at an edge.
• 3.4Describe compression and rarefaction.
• 3.4Know that, in general, sound travels faster in solids than in liquids and faster in liquids than in gases.
• 3.4Describe the uses of ultrasound in non-destructive testing of materials, medical scanning of soft tissue and sonar, including calculation of depth or distance from time and wave speed.

CoreEvery candidate

• 3.2.1Define and use the terms normal, angle of incidence and angle of reflection.
• 3.2.1Describe the formation of an optical image by a plane mirror and give its characteristics, i.e. same size, same distance from mirror, virtual.
• 3.2.1State that for reflection, the angle of incidence is equal to the angle of reflection; recall and use this relationship.
• 3.2.2Define and use the terms normal, angle of incidence and angle of refraction.
• 3.2.2Describe an experiment to show refraction of light by transparent blocks of different shapes.
• 3.2.2Describe the passage of light through a transparent material (limited to the boundaries between two mediums only).
• 3.2.2State the meaning of critical angle.
• 3.2.2Describe internal reflection and total internal reflection using both experimental and everyday examples.
• 3.2.3Describe the action of thin converging and thin diverging lenses on a parallel beam of light.
• 3.2.3Define and use the terms focal length, principal axis and principal focus (focal point).
• 3.2.3Draw and use ray diagrams for the formation of a real image by a converging lens.
• 3.2.3Describe the characteristics of an image using the terms enlarged/same size/diminished, upright/inverted and real/virtual.
• 3.2.3Know that a virtual image is formed when diverging rays are extrapolated backwards and does not form a visible projection on a screen.
• 3.2.4Describe the dispersion of light as illustrated by the refraction of white light by a glass prism.
• 3.2.4Know the traditional seven colours of the visible spectrum in order of frequency and in order of wavelength.

SupplementExtended candidates only

• 3.2.1Use simple constructions, measurements and calculations for reflection by plane mirrors.
• 3.2.2Define refractive index, n, as the ratio of the speeds of a wave in two different regions.
• 3.2.2Recall and use the equation n = sin i / sin r.
• 3.2.2Recall and use the equation n = 1 / sin c.
• 3.2.2Describe the use of optical fibres, particularly in telecommunications.
• 3.2.3Draw and use ray diagrams for the formation of a virtual image by a converging lens.
• 3.2.3Describe the use of a single lens as a magnifying glass.
• 3.2.3Describe the use of converging and diverging lenses to correct long-sightedness and short-sightedness.
• 3.2.4Recall that visible light of a single frequency is described as monochromatic.

CoreEvery candidate

• 3.3Know the main regions of the electromagnetic spectrum in order of frequency and in order of wavelength.
• 3.3Know that all electromagnetic waves travel at the same high speed in a vacuum.
• 3.3Describe typical uses of the different regions of the electromagnetic spectrum, including radio waves (radio and television transmissions, astronomy, RFID), microwaves (satellite television, mobile phones, microwave ovens), infrared (electric grills, short-range communications such as TV remote controllers, intruder alarms, thermal imaging, optical fibres), visible light (vision, photography, illumination), ultraviolet (security marking, detecting fake bank notes, sterilising water), X-rays (medical scanning, security scanners) and gamma rays (sterilising food and medical equipment, detection and treatment of cancer).
• 3.3Describe the harmful effects on people of excessive exposure to electromagnetic radiation, including microwaves (internal heating of body cells), infrared (skin burns), ultraviolet (damage to surface cells and eyes, leading to skin cancer and eye conditions), and X-rays and gamma rays (mutation or damage to cells in the body).
• 3.3Know that communication with artificial satellites is mainly by microwaves: some satellite phones use low orbit artificial satellites; some satellite phones and direct broadcast satellite television use geostationary satellites.

SupplementExtended candidates only

• 3.3Know that the speed of electromagnetic waves in a vacuum is 3.0 × 10⁸ m/s and is approximately the same in air.
• 3.3Know that many important systems of communications rely on electromagnetic radiation, including mobile phones and wireless internet using microwaves (they penetrate some walls and need only a short aerial), Bluetooth using radio waves (they pass through walls but the signal is weakened), and optical fibres using visible light or infrared for cable television and high-speed broadband (glass is transparent to visible light and some infrared; visible light and short-wavelength infrared carry high rates of data).
• 3.3Know the difference between a digital and an analogue signal.
• 3.3Know that a sound can be transmitted as a digital or analogue signal.
• 3.3Explain the benefits of digital signalling, including increased rate of transmission of data and increased range due to accurate signal regeneration.

CoreEvery candidate

• 4.2.1State that there are positive and negative charges.
• 4.2.1State that positive charges repel other positive charges, negative charges repel other negative charges, but positive charges attract negative charges.
• 4.2.1Describe simple experiments to show the production of electrostatic charges by friction and to show the detection of electrostatic charges.
• 4.2.1Explain that charging of solids by friction involves only a transfer of negative charge (electrons).
• 4.2.1Describe an experiment to distinguish between electrical conductors and insulators.
• 4.2.1Recall and use a simple electron model to explain the difference between electrical conductors and insulators and give typical examples.
• 4.2.2Know that electric current is related to the flow of charge.
• 4.2.2Describe the use of ammeters (analogue and digital) with different ranges.
• 4.2.2Describe electrical conduction in metals in terms of the movement of free electrons.
• 4.2.2Know the difference between direct current (d.c.) and alternating current (a.c.).
• 4.2.3Define electromotive force (e.m.f.) as the electrical work done by a source in moving a unit charge around a complete circuit.
• 4.2.3Know that e.m.f. is measured in volts (V).
• 4.2.3Define potential difference (p.d.) as the work done by a unit charge passing through a component.
• 4.2.3Know that the p.d. between two points is measured in volts (V).
• 4.2.3Describe the use of voltmeters (analogue and digital) with different ranges.
• 4.2.4Recall and use the equation for resistance R = V/I.
• 4.2.4Describe an experiment to determine resistance using a voltmeter and an ammeter and do the appropriate calculations.
• 4.2.4State, qualitatively, the relationship of the resistance of a metallic wire to its length and to its cross-sectional area.
• 4.2.5Understand that electric circuits transfer energy from a source of electrical energy, such as an electrical cell or mains supply, to the circuit components and then into the surroundings.
• 4.2.5Recall and use the equations for electrical power P = IV and electrical energy E = IVt.
• 4.2.5Define the kilowatt-hour (kW h) and calculate the cost of using electrical appliances where the energy unit is the kW h.
• 4.3.1Draw and interpret circuit diagrams containing cells, batteries, power supplies, generators, potential dividers, switches, resistors (fixed and variable), heaters, thermistors (NTC only), light-dependent resistors (LDRs), lamps, motors, bells, ammeters, voltmeters, magnetising coils, transformers, fuses and relays, and know how these components behave in the circuit.
• 4.3.2Know that the current at every point in a series circuit is the same.
• 4.3.2Know how to construct and use series and parallel circuits.
• 4.3.2Calculate the combined e.m.f. of several sources in series.
• 4.3.2Calculate the combined resistance of two or more resistors in series.
• 4.3.2State that, for a parallel circuit, the current from the source is larger than the current in each branch.
• 4.3.2State that the combined resistance of two resistors in parallel is less than that of either resistor by itself.
• 4.3.2State the advantages of connecting lamps in parallel in a lighting circuit.
• 4.3.3Know that the p.d. across an electrical conductor increases as its resistance increases for a constant current.
• 4.4State the hazards of damaged insulation, overheating cables, damp conditions, and excess current from overloading plugs, extension leads, single and multiple sockets when using a mains supply.
• 4.4Know that a mains circuit consists of a live wire (line wire), a neutral wire and an earth wire, and explain why a switch must be connected to the live wire for the circuit to be switched off safely.
• 4.4Explain the use and operation of trip switches and fuses, and choose appropriate fuse ratings and trip switch settings.
• 4.4Explain why the outer casing of an electrical appliance must be either non-conducting (double-insulated) or earthed.
• 4.4State that a fuse without an earth wire protects the circuit and the cabling for a double-insulated appliance.

SupplementExtended candidates only

• 4.2.1State that charge is measured in coulombs.
• 4.2.1Describe an electric field as a region in which an electric charge experiences a force.
• 4.2.1State that the direction of an electric field at a point is the direction of the force on a positive charge at that point.
• 4.2.1Describe simple electric field patterns, including around a point charge, around a charged conducting sphere and between two oppositely charged parallel conducting plates (end effects will not be examined).
• 4.2.2Define electric current as the charge passing a point per unit time; recall and use the equation I = Q/t.
• 4.2.2State that conventional current is from positive to negative and that the flow of free electrons is from negative to positive.
• 4.2.3Recall and use the equation for e.m.f. E = W/Q.
• 4.2.3Recall and use the equation for p.d. V = W/Q.
• 4.2.4Sketch and explain the current–voltage graphs for a resistor of constant resistance, a filament lamp and a diode.
• 4.2.4Recall and use the following relationships for a metallic electrical conductor: resistance is directly proportional to length; resistance is inversely proportional to cross-sectional area.
• 4.3.1Draw and interpret circuit diagrams containing diodes and light-emitting diodes (LEDs) and know how these components behave in the circuit.
• 4.3.2Recall and use in calculations the fact that the sum of the currents entering a junction equals the sum leaving it; the total p.d. across components in series equals the sum of the individual p.d.s; and the p.d. across parallel branches is the same as across one branch.
• 4.3.2Explain that the sum of the currents into a junction is the same as the sum of the currents out of it.
• 4.3.2Calculate the combined resistance of two resistors in parallel.
• 4.3.3Describe the action of a variable potential divider.
• 4.3.3Recall and use the equation for two resistors used as a potential divider R₁/R₂ = V₁/V₂.

CoreEvery candidate

• 4.1Describe the forces between magnetic poles and between magnets and magnetic materials, including the use of the terms north pole (N pole), south pole (S pole), attraction, repulsion, magnetised and unmagnetised.
• 4.1Describe induced magnetism.
• 4.1State the differences between the properties of temporary magnets (made of soft iron) and the properties of permanent magnets (made of steel).
• 4.1State the difference between magnetic and non-magnetic materials.
• 4.1Describe a magnetic field as a region in which a magnetic pole experiences a force.
• 4.1Draw the pattern and direction of the magnetic field lines around a bar magnet.
• 4.1State that the direction of a magnetic field at a point is the direction of the force on the N pole of a magnet at that point.
• 4.1Describe the plotting of magnetic field lines with a compass or iron filings and the use of a compass to determine the direction of the magnetic field.
• 4.1Describe the uses of permanent magnets and electromagnets.
• 4.5.1Know that a conductor moving across a magnetic field, or a changing magnetic field linking with a conductor, can induce an e.m.f. in the conductor.
• 4.5.1Describe an experiment to demonstrate electromagnetic induction.
• 4.5.1State the factors affecting the magnitude of an induced e.m.f.
• 4.5.3Describe the pattern and direction of the magnetic field due to currents in straight wires and in solenoids.
• 4.5.3Describe an experiment to identify the pattern of the magnetic field (including direction) due to currents in straight wires and in solenoids.
• 4.5.3Describe how the magnetic effect of a current is used in relays and loudspeakers and give examples of their application.
• 4.5.4Describe an experiment to show that a force acts on a current-carrying conductor in a magnetic field, including the effect of reversing the current or the direction of the field.
• 4.5.5Know that a current-carrying coil in a magnetic field may experience a turning effect, increased by more turns, larger current or a stronger field.
• 4.5.6Describe the construction of a simple transformer with a soft-iron core, as used for voltage transformations.
• 4.5.6Use the terms primary, secondary, step-up and step-down.
• 4.5.6Recall and use the equation Vp / Vs = Np / Ns.
• 4.5.6Describe the use of transformers in high-voltage transmission of electricity.
• 4.5.6State the advantages of high-voltage transmission.

SupplementExtended candidates only

• 4.1Explain that magnetic forces are due to interactions between magnetic fields.
• 4.1Know that the relative strength of a magnetic field is represented by the spacing of the magnetic field lines.
• 4.5.1Know that the direction of an induced e.m.f. opposes the change causing it.
• 4.5.1State and use the relative directions of force, field and induced current.
• 4.5.2Describe a simple form of a.c. generator (rotating coil or rotating magnet) and the use of slip rings and brushes where needed.
• 4.5.2Sketch and interpret graphs of e.m.f. against time for simple a.c. generators and relate the position of the generator coil to the peaks, troughs and zeros of the e.m.f.
• 4.5.3State the qualitative variation of the strength of the magnetic field around straight wires and solenoids.
• 4.5.3Describe the effect on the magnetic field around straight wires and solenoids of changing the magnitude and direction of the current.
• 4.5.4Recall and use the relative directions of force, magnetic field and current.
• 4.5.4Determine the direction of the force on beams of charged particles in a magnetic field.
• 4.5.5Describe the operation of an electric motor, including the action of a split-ring commutator and brushes.
• 4.5.6Explain the principle of operation of a simple iron-cored transformer.
• 4.5.6Recall and use the equation IpVp = IsVs for 100% efficiency.
• 4.5.6Recall and use the equation P = I²R to explain why power losses in cables are smaller when the voltage is greater.

CoreEvery candidate

• 5.1.1Describe the structure of an atom in terms of a positively charged nucleus and negatively charged electrons in orbit around the nucleus.
• 5.1.1Know how atoms may form positive ions by losing electrons or form negative ions by gaining electrons.
• 5.1.2Describe the composition of the nucleus in terms of protons and neutrons.
• 5.1.2State the relative charges of protons, neutrons and electrons as +1, 0 and −1 respectively.
• 5.1.2Define the terms proton number (atomic number) Z and nucleon number (mass number) A, and be able to calculate the number of neutrons in a nucleus.
• 5.1.2Use the nuclide notation (A top-left, Z bottom-left beside the symbol).
• 5.1.2Explain what is meant by an isotope and state that an element may have more than one isotope.
• 5.2.1Know what is meant by background radiation.
• 5.2.1Know the sources that make a significant contribution to background radiation, including radon gas (in the air), rocks and buildings, food and drink, and cosmic rays.
• 5.2.1Know that ionising nuclear radiation can be measured using a detector connected to a counter.
• 5.2.1Use count rate measured in counts per second or counts per minute.
• 5.2.2Describe the emission of radiation from a nucleus as spontaneous and random in direction.
• 5.2.2Identify alpha, beta and gamma emissions from the nucleus by recalling their nature, their relative ionising effects and their relative penetrating abilities (β⁺ are not included; β-particles will be taken to refer to β⁻).
• 5.2.3Know that radioactive decay is a change in an unstable nucleus that can result in the emission of alpha-particles or beta-particles and/or gamma radiation, and that these changes are spontaneous and random.
• 5.2.3State that during alpha-decay or beta-decay, the nucleus changes to that of a different element.
• 5.2.4Define the half-life of a particular isotope as the time taken for half the nuclei of that isotope in any sample to decay; recall and use this definition in simple calculations, which might involve information in tables or decay curves (calculations will not include background radiation).
• 5.2.5State the effects of ionising nuclear radiations on living things, including cell death, mutations and cancer.
• 5.2.5Describe how radioactive materials are moved, used and stored in a safe way.

SupplementExtended candidates only

• 5.1.1Describe how the scattering of alpha particles by a sheet of thin metal supports the nuclear model of the atom, by providing evidence for a very small nucleus surrounded by mostly empty space, a nucleus containing most of the mass of the atom, and a nucleus that is positively charged.
• 5.1.2Describe the processes of nuclear fission and nuclear fusion as the splitting or joining of nuclei, to include the nuclide equation and qualitative description of mass and energy changes without values.
• 5.1.2Know the relationship between the proton number and the relative charge on a nucleus.
• 5.1.2Know the relationship between the nucleon number and the relative mass of a nucleus.
• 5.2.1Use measurements of background radiation to determine a corrected count rate.
• 5.2.2Describe the deflection of alpha, beta and gamma radiation in electric fields and in magnetic fields.
• 5.2.2Explain their relative ionising effects with reference to their kinetic energy and their electric charge.
• 5.2.3Know that isotopes of an element may be radioactive due to an excess of neutrons in the nucleus and/or the nucleus being too heavy.
• 5.2.3Describe the effect of alpha-decay, beta-decay and gamma-emissions on the nucleus, including an increase in stability and a reduction in the number of excess neutrons; during beta-emission a neutron changes into a proton plus an electron.
• 5.2.3Use decay equations, using nuclide notation, to show the emission of alpha-particles, beta-particles and gamma radiation.
• 5.2.4Calculate half-life from data or decay curves from which background radiation has not been subtracted.
• 5.2.4Explain how the type of radiation emitted and the half-life of an isotope determine which isotope is used for applications, including household smoke alarms, irradiating food to kill bacteria, sterilisation of equipment using gamma rays, measuring and controlling thicknesses of materials, and diagnosis and treatment of cancer using gamma rays.
• 5.2.5Explain safety precautions for all ionising radiation in terms of reducing exposure time, increasing distance between source and living tissue, and using shielding to absorb radiation.

CoreEvery candidate

• 6.1.1Know that the Earth is a planet that rotates on its axis, which is tilted, once in approximately 24 hours, and use this to explain observations of the apparent daily motion of the Sun and the periodic cycle of day and night.
• 6.1.1Know that the Earth orbits the Sun once in approximately 365 days and use this to explain the periodic nature of the seasons.
• 6.1.1Know that it takes approximately one month for the Moon to orbit the Earth and use this to explain the periodic nature of the Moon’s cycle of phases.
• 6.1.2Describe the Solar System as containing one star (the Sun), the eight named planets in order from the Sun, minor planets including dwarf planets such as Pluto and asteroids in the asteroid belt, moons orbiting the planets, and smaller Solar System bodies including comets and natural satellites.
• 6.1.2Know that the four planets nearest the Sun are rocky and small and the four planets furthest from the Sun are gaseous and large, and explain this difference by referring to an accretion model for Solar System formation, including the model’s dependence on gravity, the presence of many elements in interstellar clouds of gas and dust, and the rotation of material in the cloud and the formation of an accretion disc.
• 6.1.2Know that the strength of the gravitational field (a) at the surface of a planet depends on the mass of the planet, and (b) around a planet decreases as the distance from the planet increases.
• 6.1.2Calculate the time it takes light to travel a significant distance such as between objects in the Solar System.
• 6.1.2Know that the Sun contains most of the mass of the Solar System and this explains why the planets orbit the Sun.
• 6.1.2Know that the force that keeps an object in orbit around the Sun is the gravitational attraction of the Sun.
• 6.2.1Know that the Sun is a star of medium size, consisting mostly of hydrogen and helium, and that it radiates most of its energy in the infrared, visible light and ultraviolet regions of the electromagnetic spectrum.
• 6.2.2State that galaxies are each made up of many billions of stars, that the Sun is a star in the galaxy known as the Milky Way, that other stars of the Milky Way are much further away from the Earth than the Sun, and that astronomical distances can be measured in light-years (the distance travelled in space by light in one year).
• 6.2.3Know that the Milky Way is one of many billions of galaxies making up the Universe, and that the diameter of the Milky Way is approximately 100 000 light-years.
• 6.2.3Describe redshift as an increase in the observed wavelength of electromagnetic radiation emitted from receding stars and galaxies.
• 6.2.3Know that the light emitted from distant galaxies appears redshifted in comparison with light emitted on the Earth.
• 6.2.3Know that redshift in the light from distant galaxies is evidence that the Universe is expanding and supports the Big Bang Theory.

SupplementExtended candidates only

• 6.1.1Define average orbital speed from the equation v = 2πr/T; recall and use this equation.
• 6.1.2Know that planets, minor planets and comets have elliptical orbits, and recall that the Sun is not at the centre of the elliptical orbit, except when the orbit is approximately circular.
• 6.1.2Analyse and interpret planetary data about orbital distance, orbital duration, density, surface temperature and uniform gravitational field strength at the planet’s surface.
• 6.1.2Know that the strength of the Sun’s gravitational field decreases and that the orbital speeds of the planets decrease as the distance from the Sun increases.
• 6.1.2Know that an object in an elliptical orbit travels faster when closer to the Sun and explain this using the conservation of energy.
• 6.2.1Know that stars are powered by nuclear reactions that release energy and that in stable stars the nuclear reactions involve the fusion of hydrogen into helium.
• 6.2.2Know that one light-year is equal to 9.5 × 10¹⁵ m.
• 6.2.2Describe the life cycle of a star: formation from interstellar clouds of gas and dust containing hydrogen; protostar as a collapsing cloud heating by its internal gravitational attraction; stability when inward gravitational force is balanced by outward force due to the high temperature; eventual running out of hydrogen as fuel; expansion into red giants (or red supergiants for more massive stars); a red giant forming a planetary nebula with a white dwarf at its centre; a red supergiant exploding as a supernova forming a nebula with hydrogen and new heavier elements and leaving a neutron star or black hole; the supernova nebula possibly forming new stars with orbiting planets.
• 6.2.3Know that microwave radiation of a specific frequency is observed at all points in space around us, known as cosmic microwave background radiation (CMBR).
• 6.2.3Explain that the CMBR was produced shortly after the Universe was formed and that this radiation has been expanded into the microwave region of the electromagnetic spectrum as the Universe expanded.
• 6.2.3Know that the speed v at which a galaxy is moving away from the Earth can be found from the change in wavelength of the galaxy’s starlight due to redshift.
• 6.2.3Know that the distance d of a far galaxy can be determined using the brightness of a supernova in that galaxy.
• 6.2.3Define the Hubble constant H₀ as the ratio of the speed at which a galaxy is receding to its distance; recall and use H₀ = v/d.
• 6.2.3Know that the current estimate for H₀ is 2.2 × 10⁻¹⁸ per second.
• 6.2.3Know that the equation d/v = 1/H₀ represents an estimate for the age of the Universe and that this is evidence for the idea that all the matter in the Universe was present at a single point.