Physics

Physics 0625 — specification explorer

All 294 specification statements from the official Cambridge International specification, as printed.

Paper/unit applicability has not been derived for this course yet — the statements below are the parsed specification, as printed.

1. Motion, forces and energy

1. Physical quantities and measurement techniques

1.1.1Describe the use of rulers and measuring cylinders to find a length or a volume
1.1.2Describe how to measure a variety of time intervals using clocks and digital timers
1.1.3Determine 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)
1.1.4Understand that a scalar quantity has magnitude (size) only and that a vector quantity has magnitude and direction
1.1.5Know that the following quantities are scalars: distance, speed, time, mass, energy and temperature
1.1.6Know that the following quantities are vectors: force, weight, velocity, acceleration, momentum, electric field strength and gravitational field strength
1.1.7Determine, by calculation or graphically, the resultant of two vectors at right angles, limited to forces or velocities only

2. Motion

1.2.1Define speed as distance travelled per unit time; recall and use the equation
1.2.2Define velocity as speed in a given direction
1.2.3Recall and use the equation total distance travelled average speed = total time taken
1.2.4Sketch, plot and interpret distance–time and speed–time graphs
1.2.5
Determine, qualitatively, from given data or the shape of a distance–time graph or speed–time graph when an object is:
- (a) at rest
- (b) moving with constant speed
- (c) accelerating
- (d) decelerating
1.2.6Calculate speed from the gradient of a straight- line section of a distance–time graph
1.2.7Calculate the area under a speed–time graph to determine the distance travelled for motion with constant speed or constant acceleration
1.2.8State that the acceleration of free fall g for an object near to the surface of the Earth is approximately constant and is approximately
1.2.9Define acceleration as change in velocity per unit time; recall and use the equation
1.2.10
Determine from given data or the shape of a speed–time graph when an object is moving with:
- (a) constant acceleration
- (b) changing acceleration
1.2.11Calculate acceleration from the gradient of a speed–time graph
1.2.12Know that a deceleration is a negative acceleration and use this in calculations
1.2.13Describe the motion of objects falling in a uniform gravitational field with and without air/ liquid resistance (including reference to terminal velocity)

3. Mass and weight

1.3.1State that mass is a measure of the quantity of matter in an object at rest relative to the observer
1.3.2State that weight is a gravitational force on an object that has mass
1.3.3Define gravitational field strength as force per unit mass; recall and use the equation and know that this is equivalent to the acceleration of free fall
1.3.4Know that weights (and masses) may be compared using a balance
1.3.5Describe, and use the concept of, weight as the effect of a gravitational field on a mass

4. Density

1.4.1Define density as mass per unit volume; recall and use the equation
1.4.2Describe 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
1.4.3Determine whether an object floats based on density data 1.5.1 Effects of forces
1.4.4Determine whether one liquid will float on another liquid based on density data given that the liquids do not mix

5. Forces

1.5.1Know that forces may produce changes in the size and shape of an object
1.5.1aDescribe the moment of a force as a measure of its turning effect and give everyday examples
1.5.1bState what is meant by centre of gravity
1.5.2Sketch, plot and interpret load–extension graphs for an elastic solid and describe the associated experimental procedures
1.5.2aDefine the moment of a force as moment = force × perpendicular distance from the pivot; recall and use this equation
1.5.2bDescribe an experiment to determine the position of the centre of gravity of an irregularly shaped plane lamina
1.5.3Determine the resultant of two or more forces acting along the same straight line
1.5.3aApply the principle of moments to situations with one force each side of the pivot, including balancing of a beam
1.5.3bDescribe, qualitatively, the effect of the position of the centre of gravity on the stability of simple objects
1.5.4Know that an object either remains at rest or continues in a straight line at constant speed unless acted on by a resultant force
1.5.4aState that, when there is no resultant force and no resultant moment, an object is in equilibrium 1.5.3 Centre of gravity
1.5.5State that a resultant force may change the velocity of an object by changing its direction of motion or its speed
1.5.5aApply the principle of moments to other situations, including those with more than one force each side of the pivot
1.5.6Describe solid friction as the force between two surfaces that may impede motion and produce heating
1.5.6aDescribe an experiment to demonstrate that there is no resultant moment on an object in equilibrium
1.5.7Know that friction (drag) acts on an object moving through a liquid
1.5.8Know that friction (drag) acts on an object moving through a gas (e.g. air resistance) 1.5.2 Turning effect of forces
1.5.9Define the spring constant as force per unit extension; recall and use the equation
1.5.10Define 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)
1.5.11Recall and use the equation F = ma and know that the force and the acceleration are in the same direction
1.5.12
Describe, qualitatively, motion in a circular path due to a force perpendicular to the motion as: and radius constant and speed constant to keep speed and radius constant ( F = is not required) continued:
- (a) speed increases if force increases, with mass
- (b) radius decreases if force increases, with mass
- (c) an increased mass requires an increased force

6. Momentum

1.6.1Define momentum as mass × velocity; recall and use the equation
1.6.2Define impulse as force × time for which force acts; recall and use the equation impulse = F ∆ t = ∆ ( mv )
1.6.3Apply the principle of the conservation of momentum to solve simple problems in one dimension
1.6.4Define resultant force as the change in momentum per unit time; recall and use the equation

7. Energy, work and power

1.7.1State that energy may be stored as kinetic, gravitational potential, chemical, elastic (strain), nuclear, electrostatic and internal (thermal)
1.7.1aUnderstand that mechanical or electrical work done is equal to the energy transferred
1.7.1b
Describe how useful energy may be obtained, or electrical power generated, from: in tides, and in water behind hydroelectric dams power (solar cells) from the Sun to heat water (solar panels) and be the source of wind energy including references to a boiler, turbine and generator where they are used:
- (a) chemical energy stored in fossil fuels
- (b) chemical energy stored in biofuels
- (c) water, including the energy stored in waves,
- (d) geothermal resources
- (e) nuclear fuel
- (f) light from the Sun to generate electrical
- (g) infrared and other electromagnetic waves
1.7.1c
Define power as work done per unit time and also as energy transferred per unit time; recall and use the equations:
- (a) P =
- (b) P =
1.7.2Describe 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
1.7.2aRecall and use the equation for mechanical working W = Fd = ∆ E 1.7.3 Energy resources
1.7.2bDescribe advantages and disadvantages of each method in terms of renewability, availability, reliability, scale and environmental impact
1.7.3Know the principle of the conservation of energy and apply this principle to simple examples including the interpretation of simple flow diagrams
1.7.3aUnderstand, qualitatively, the concept of efficiency of energy transfer
1.7.4Recall and use the equation for kinetic energy E = 1/2 mv
1.7.4aKnow that radiation from the Sun is the main source of energy for all our energy resources except geothermal, nuclear and tidal
1.7.5Recall and use the equation for the change in gravitational potential energy ∆ E = mg ∆ h
1.7.5aKnow that energy is released by nuclear fusion in the Sun
1.7.6Know the principle of the conservation of energy and apply this principle to complex examples involving multiple stages, including the interpretation of Sankey diagrams
1.7.6aKnow 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
1.7.7Define efficiency as: (useful energy output) (%) efficiency = ( × 100%) (total energy input) (useful power output) (%) efficiency = ( × 100%) (total power input) recall and use these equations

8. Pressure

1.8.1Define pressure as force per unit area; recall and use the equation
1.8.2Describe how pressure varies with force and area in the context of everyday examples
1.8.3Describe, qualitatively, how the pressure beneath the surface of a liquid changes with depth and density of the liquid 2.1.1 States of matter
1.8.4Recall and use the equation for the change in pressure beneath the surface of a liquid

2. Thermal physics

1. Kinetic particle model of matter

2.1.1Know the distinguishing properties of solids, liquids and gases
2.1.1aDescribe 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
2.1.1b
Describe qualitatively, in terms of particles, the effect on the pressure of a fixed mass of gas of:
- (a) a change of temperature at constant volume
- (b) a change of volume at constant temperature
2.1.2Know the terms for the changes in state between solids, liquids and gases (gas to solid and solid to gas transfers are not required)
2.1.2aDescribe 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
2.1.2bConvert temperatures between kelvin and degrees Celsius; recall and use the equation T (in K) = θ (in °C) + 273
2.1.3Describe the pressure and the changes in pressure of a gas in terms of the motion of its particles and their collisions with a surface
2.1.4Know that the random motion of microscopic particles in a suspension is evidence for the kinetic particle model of matter
2.1.5Describe and explain this motion (sometimes known as Brownian motion) in terms of random collisions between the microscopic particles in a suspension and the particles of the gas or liquid 2.1.3 Gases and the absolute scale of temperature
2.1.6Know that the forces and distances between particles (atoms, molecules, ions and electrons) and the motion of the particles affects the properties of solids, liquids and gases
2.1.7Describe 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
2.1.8Know 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 pV = constant for a fixed mass of gas at constant temperature, including a graphical representation of this relationship

2. Thermal properties and temperature

2.2.1Describe, qualitatively, the thermal expansion of solids, liquids and gases at constant pressure
2.2.1aKnow that a rise in the temperature of an object increases its internal energy 2.2.3 Melting, boiling and evaporation
2.2.1bDescribe melting and boiling in terms of energy input without a change in temperature
2.2.2Describe some of the everyday applications and consequences of thermal expansion 2.2.2 Specific heat capacity
2.2.2aKnow the melting and boiling temperatures for water at standard atmospheric pressure
2.2.3Describe condensation and solidification in terms of particles
2.2.3aExplain, 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 in terms of an increase in the average kinetic energies of all of the particles in the object required per unit mass per unit temperature increase; recall and use the equation
2.2.4Describe evaporation in terms of the escape of more energetic particles from the surface of a liquid
2.2.4aDescribe experiments to measure the specific heat capacity of a solid and a liquid evaporation movement over a surface affect evaporation an evaporating liquid
2.2.5Know that evaporation causes cooling of a liquid

3. Transfer of thermal energy

2.3.1Describe experiments to demonstrate the properties of good thermal conductors and bad thermal conductors (thermal insulators) 2.3.2 Convection
2.3.1aKnow that convection is an important method of thermal energy transfer in liquids and gases
2.3.1bKnow that thermal radiation is infrared radiation and that all objects emit this radiation
2.3.1c
Explain some of the basic everyday applications and consequences of conduction, convection and radiation, including:
- (a) heating objects such as kitchen pans
- (b) heating a room by convection
2.3.2Explain convection in liquids and gases in terms of density changes and describe experiments to illustrate convection 2.3.3 Radiation
2.3.2aKnow that thermal energy transfer by thermal radiation does not require a medium
2.3.2bDescribe 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
2.3.3Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of infrared radiation
2.3.3aDescribe, in terms of particles, why thermal conduction is bad in gases and most liquids
2.3.4Know that there are many solids that conduct thermal energy better than thermal insulators but do so less well than good thermal conductors temperature it needs to transfer energy away from the object at the same rate that it receives energy
2.3.5Know 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
2.3.6Know how the temperature of the Earth is affected by factors controlling the balance between incoming radiation and radiation emitted from the Earth’s surface continued
2.3.7Describe experiments to distinguish between good and bad emitters of infrared radiation
2.3.8Describe experiments to distinguish between good and bad absorbers of infrared radiation
2.3.9
Describe how the rate of emission of radiation depends on the surface temperature and surface area of an object consequences of conduction, convection and radiation where more than one type of thermal energy transfer is significant, including:
- (a) a fire burning wood or coal
- (b) a radiator in a car

3. Waves

1. General properties of waves

3.1.1Know that waves transfer energy without transferring matter
3.1.2Describe what is meant by wave motion as illustrated by vibrations in ropes and springs, and by experiments using water waves
3.1.3Describe the features of a wave in terms of wavefront, wavelength, frequency, crest (peak), trough, amplitude and wave speed
3.1.4Recall and use the equation for wave speed
3.1.5Know 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 continued
3.1.6Know 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
3.1.7
Describe how waves can undergo:
- (a) reflection at a plane surface
- (b) refraction due to a change of speed
- (c) diffraction through a narrow gap
3.1.8
Describe the use of a ripple tank to show: a change in depth 3.2.1 Reflection of light:
- (a) reflection at a plane surface
- (b) refraction due to a change in speed caused by
- (c) diffraction due to a gap
- (d) diffraction due to an edge
3.1.9Describe how wavelength and gap size affects diffraction through a gap
3.1.10Describe how wavelength affects diffraction at an edge

2. Light

3.2.1Define and use the terms normal, angle of incidence and angle of reflection
3.2.1aDefine and use the terms normal, angle of incidence and angle of refraction
3.2.1bDescribe the action of thin converging and thin diverging lenses on a parallel beam of light
3.2.1cDescribe the dispersion of light as illustrated by the refraction of white light by a glass prism
3.2.2Describe the formation of an optical image by a plane mirror, and give its characteristics, i.e. same size, same distance from mirror, virtual
3.2.2aDescribe an experiment to show refraction of light by transparent blocks of different shapes
3.2.2bDefine and use the terms focal length, principal axis and principal focus (focal point)
3.2.2cKnow the traditional seven colours of the visible spectrum in order of frequency and in order of wavelength
3.2.3State that for reflection, the angle of incidence is equal to the angle of reflection; recall and use this relationship
3.2.3aDescribe the passage of light through a transparent material (limited to the boundaries between two media only)
3.2.3bDraw and use ray diagrams for the formation of a real image by a converging lens
3.2.4Use simple constructions, measurements and calculations for reflection by plane mirrors
3.2.4aState the meaning of critical angle
3.2.4bDescribe the characteristics of an image using the terms enlarged/same size/diminished, upright/inverted and real/virtual
3.2.5Describe internal reflection and total internal reflection using both experimental and everyday examples 3.2.3 Thin lenses
3.2.5aKnow that a virtual image is formed when diverging rays are extrapolated backwards and does not form a visible projection on a screen 3.2.4 Dispersion of light
3.2.6Define refractive index, n , as the ratio of the speeds of a wave in two different regions
3.2.7Recall and use the equation sin i sin r
3.2.8Recall and use the equation sin c
3.2.9Describe the use of optical fibres, particularly in telecommunications virtual image by a converging lens glass lenses to correct long-sightedness and short- sightedness described as monochromatic

3. Electromagnetic spectrum

3.3.1Know the main regions of the electromagnetic spectrum in order of frequency and in order of wavelength
3.3.2Know that all electromagnetic waves travel at the same high speed in a vacuum
3.3.3
Describe typical uses of the different regions of the electromagnetic spectrum including: transmissions, astronomy, radio frequency identification (RFID) phones (cell phones), microwave ovens communications such as remote controllers for televisions, intruder alarms, thermal imaging, optical fibres bank notes, sterilising water equipment, detection of cancer and its treatment:
- (a) radio waves; radio and television
- (b) microwaves; satellite television, mobile
- (c) infrared; electric grills, short range
- (d) visible light; vision, photography, illumination
- (e) ultraviolet; security marking, detecting fake
- (f) X-rays; medical scanning, security scanners
- (g) gamma rays; sterilising food and medical
3.3.4
Describe the harmful effects on people of excessive exposure to electromagnetic radiation, including: leading to skin cancer and eye conditions to cells in the body continued:
- (a) microwaves; internal heating of body cells
- (b) infrared; skin burns
- (c) ultraviolet; damage to surface cells and eyes,
- (d) X-rays and gamma rays; mutation or damage
3.3.5
Know that communication with artificial satellites is mainly by microwaves: satellites satellite television use geostationary satellites:
- (a) some satellite phones use low orbit artificial
- (b) some satellite phones and direct broadcast
3.3.6Know that the speed of electromagnetic waves in a vacuum is 3.0 × 10 m / s and is approximately the same in air
3.3.7
Know that many important systems of communications rely on electromagnetic radiation including: internet use microwaves because microwaves can penetrate some walls and only require a short aerial for transmission and reception microwaves because they can pass through walls but the signal is weakened on doing so used for cable television and high-speed broadband because glass is transparent to visible light and some infrared; visible light and short wavelength infrared can carry high rates of data:
- (a) mobile phones (cell phones) and wireless
- (b) Bluetooth uses low energy radio waves or
- (c) optical fibres (visible light or infrared) are
3.3.8Know the difference between a digital and analogue signal
3.3.9Know that a sound can be transmitted as a digital or analogue signal
3.3.10Explain the benefits of digital signaling including increased rate of transmission of data and increased range due to accurate signal regeneration

4. Sound

3.4.1Describe the production of sound by vibrating sources
3.4.2Describe the longitudinal nature of sound waves
3.4.3State the approximate range of frequencies audible to humans as 20 Hz to 20 000 Hz
3.4.4Know that a medium is needed to transmit sound waves
3.4.5Know that the speed of sound in air is approximately 330–350 m / s
3.4.6Describe a method involving a measurement of distance and time for determining the speed of sound in air
3.4.7Describe how changes in amplitude and frequency affect the loudness and pitch of sound waves
3.4.8Describe an echo as the reflection of sound waves
3.4.9Define ultrasound as sound with a frequency higher than 20 kHz
3.4.10Describe compression and rarefaction
3.4.11Know that, in general, sound travels faster in solids than in liquids and faster in liquids than in gases continued
3.4.12Describe 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

4. Electricity and magnetism

1. Simple phenomena of magnetism

4.1.1Describe 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 and repulsion, magnetised and unmagnetised
4.1.2Describe induced magnetism
4.1.3State the differences between the properties of temporary magnets (made of soft iron) and the properties of permanent magnets (made of steel)
4.1.4State the difference between magnetic and non- magnetic materials
4.1.5Describe a magnetic field as a region in which a magnetic pole experiences a force
4.1.6Draw the pattern and direction of magnetic field lines around a bar magnet
4.1.7State 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
4.1.8Describe 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
4.1.9Describe the uses of permanent magnets and electromagnets
4.1.10Explain that magnetic forces are due to interactions between magnetic fields
4.1.11Know that the relative strength of a magnetic field is represented by the spacing of the magnetic field lines

2. Electrical quantities

4.2.1State that there are positive and negative charges
4.2.1aKnow that electric current is related to the flow of charge
4.2.1bDefine electromotive force (e.m.f.) as the electrical work done by a source in moving a unit charge around a complete circuit
4.2.1cRecall and use the equation for resistance
4.2.1dUnderstand 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
4.2.2State that positive charges repel other positive charges, negative charges repel other negative charges, but positive charges attract negative charges
4.2.2aDescribe the use of ammeters (analogue and digital) with different ranges
4.2.2bKnow that e.m.f. is measured in volts (V)
4.2.2cDescribe an experiment to determine resistance using a voltmeter and an ammeter and do the appropriate calculations
4.2.2dRecall and use the equation for electrical power
4.2.3Describe simple experiments to show the production of electrostatic charges by friction and to show the detection of electrostatic charges
4.2.3aDescribe electrical conduction in metals in terms of the movement of free electrons
4.2.3bDefine potential difference (p.d.) as the work done by a unit charge passing through a component
4.2.3cState, qualitatively, the relationship of the resistance of a metallic wire to its length and to its cross-sectional area 4.2.5 Electrical energy and electrical power
4.2.3dRecall and use the equation for electrical energy E = I Vt
4.2.4Explain that charging of solids by friction involves only a transfer of negative charge (electrons)
4.2.4aKnow the difference between direct current (d.c.) and alternating current (a.c.)
4.2.4bKnow that the p.d. between two points is measured in volts (V)
4.2.4cDefine the kilowatt-hour (kW h) and calculate the cost of using electrical appliances where the energy unit is the kW h
4.2.5Describe an experiment to distinguish between electrical conductors and insulators
4.2.5aDescribe the use of voltmeters (analogue and digital) with different ranges 4.2.4 Resistance
4.2.6Recall and use a simple electron model to explain the difference between electrical conductors and insulators and give typical examples 4.2.2 Electric current
4.2.6aRecall and use the equation for e.m.f.
4.2.7State that charge is measured in coulombs
4.2.7a
Recall and use the equation for p.d. for a resistor of constant resistance, a filament lamp and a diode metallic electrical conductor: cross-sectional area:
- (a) resistance is directly proportional to length
- (b) resistance is inversely proportional to
4.2.8Describe an electric field as a region in which an electric charge experiences a force
4.2.9State that the direction of an electric field at a point is the direction of the force on a positive charge at that point
4.2.10
Describe simple electric field patterns, including the direction of the field: conducting plates (end effects will not be examined) point per unit time; recall and use the equation to negative and that the flow of free electrons is from negative to positive:
- (a) around a point charge
- (b) around a charged conducting sphere
- (c) between two oppositely charged parallel

3. Electric circuits

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, ammeters, voltmeters, magnetising coils, transformers, fuses and relays, and know how these components behave in the circuit 4.3.2 Series and parallel circuits
4.3.1aKnow that the current at every point in a series circuit is the same
4.3.1bKnow that the p.d. across an electrical conductor increases as its resistance increases for a constant current
4.3.1c1
4.3.2Know how to construct and use series and parallel circuits
4.3.2a
Draw and interpret circuit diagrams containing diodes and light-emitting diodes (LEDs), and know how these components behave in the circuit in a parallel circuit is equal to the sum of the currents that leave the junction a series circuit is equal to the sum of the individual p.d.s across each component resistances is the same as the p.d. across one branch in the arrangement of the parallel resistances junction is the same as the sum of the currents out of the junction resistors in parallel:
- (a) the sum of the currents entering a junction
- (b) the total p.d. across the components in
- (c) the p.d. across an arrangement of parallel
4.3.2bDescribe the action of a variable potential divider
4.3.2c2
4.3.3Calculate the combined e.m.f. of several sources in series
4.3.3aRecall and use the equation for two resistors used as a potential divider
4.3.4Calculate the combined resistance of two or more resistors in series
4.3.5State that, for a parallel circuit, the current from the source is larger than the current in each branch
4.3.6State that the combined resistance of two resistors in parallel is less than that of either resistor by itself
4.3.7State the advantages of connecting lamps in parallel in a lighting circuit

4. Electrical safety

4.4.1
State the hazards of: extension leads, single and multiple sockets when using a mains supply:
- (a) damaged insulation
- (b) overheating cables
- (c) damp conditions
- (d) excess current from overloading of plugs,
4.4.2Know 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
4.4.3Explain the use and operation of trip switches and fuses and choose appropriate fuse ratings and trip switch settings
4.4.4Explain why the outer casing of an electrical appliance must be either non-conducting (double-insulated) or earthed
4.4.5State that a fuse without an earth wire protects the circuit and the cabling for a double-insulated appliance

5. Electromagnetic effects

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
4.5.1aDescribe the pattern and direction of the magnetic field due to currents in straight wires and in solenoids
4.5.1bDescribe a simple form of a.c. generator (rotating coil or rotating magnet) and the use of slip rings and brushes where needed
4.5.1c
Describe an experiment to show that a force acts on a current-carrying conductor in a magnetic field, including the effect of reversing: 4.5.5 The d.c. motor:
- (a) the current
- (b) the direction of the field
4.5.1d
Know that a current-carrying coil in a magnetic field may experience a turning effect and that the turning effect is increased by increasing: 4.5.6 The transformer:
- (a) the number of turns on the coil
- (b) the current
- (c) the strength of the magnetic field
4.5.1eDescribe the construction of a simple transformer with a soft iron core, as used for voltage transformations
4.5.2Describe an experiment to demonstrate electromagnetic induction
4.5.2aDescribe an experiment to identify the pattern of the magnetic field (including direction) due to currents in straight wires and in solenoids
4.5.2bSketch 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. of the magnetic field around straight wires and solenoids straight wires and solenoids of changing the magnitude and direction of the current
4.5.2cUse the terms primary, secondary, step-up and step-down
4.5.2dRecall and use the relative directions of force, magnetic field and current
4.5.3State the factors affecting the magnitude of an induced e.m.f. 4.5.2 The a.c. generator 4.5.3 Magnetic effect of a current
4.5.3aDescribe how the magnetic effect of a current is used in relays and loudspeakers and give examples of their application
4.5.3bRecall and use the equation where p and s refer to primary and secondary
4.5.3cDetermine the direction of the force on beams of charged particles in a magnetic field including the action of a split-ring commutator and brushes iron-cored transformer in a transformer where p and s refer to primary and secondary to explain why power losses in cables are smaller when the voltage is greater
4.5.4Know that the direction of an induced e.m.f. opposes the change causing it
4.5.4aDescribe the use of transformers in high-voltage transmission of electricity
4.5.5State and use the relative directions of force, field and induced current
4.5.5aState the advantages of high-voltage transmission

5. Nuclear physics

1. The nuclear model of the atom

5.1.1Describe the structure of an atom in terms of a positively charged nucleus and negatively charged electrons in orbit around the nucleus
5.1.1aDescribe the composition of the nucleus in terms of protons and neutrons
5.1.2Know how atoms may form positive ions by losing electrons or form negative ions by gaining electrons 5.1.2 The nucleus
5.1.2aState the relative charges of protons, neutrons and electrons as +1, 0 and –1 respectively
5.1.3Define 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
5.1.3a
Describe how the scattering of alpha (α) particles by a sheet of thin metal supports the nuclear model of the atom, by providing evidence for: empty space atom nuclear fusion as the splitting or joining of nuclei, to include the nuclide equation and qualitative description of mass and energy changes without values number and the relative charge on a nucleus number and the relative mass of a nucleus:
- (a) a very small nucleus surrounded by mostly
- (b) a nucleus containing most of the mass of the
- (c) a nucleus that is positively charged
5.1.4Use the nuclide notation Z X
5.1.5Explain what is meant by an isotope and state that an element may have more than one isotope

2. Radioactivity

5.2.1Know what is meant by background radiation
5.2.1aDescribe the emission of radiation from a nucleus as spontaneous and random in direction
5.2.1bKnow that radioactive decay is a change in an unstable nucleus that can result in the emission of α -particles or β -particles and/or γ -radiation and know that these changes are spontaneous and random
5.2.1cDefine 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)
5.2.1dState the effects of ionising nuclear radiations on living things, including cell death, mutations and cancer
5.2.2
Know the sources that make a significant contribution to background radiation including:
- (a) radon gas (in the air)
- (b) rocks and buildings
- (c) food and drink
- (d) cosmic rays
5.2.2a
Identify alpha ( α ), beta ( β ) and gamma ( γ ) emissions from the nucleus by recalling: not included, β -particles will be taken to refer to β ):
- (a) their nature
- (b) their relative ionising effects
- (c) their relative penetrating abilities ( β are
5.2.2bState that during α -decay or β -decay, the nucleus changes to that of a different element 5.2.4 Half-life
5.2.2cDescribe how radioactive materials are moved, used and stored in a safe way 6.1.1 The Earth
5.2.3Know that ionising nuclear radiation can be measured using a detector connected to a counter
5.2.3aKnow that isotopes of an element may be radioactive due to an excess of neutrons in the nucleus and/or the nucleus being too heavy
5.2.3bExplain 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
5.2.4Use count rate measured in counts / s or counts / minute 5.2.2 The three types of nuclear emission
5.2.4aDescribe the effect of α -decay, β -decay and γ -emissions on the nucleus, including an increase in stability and a reduction in the number of excess neutrons; the following change in the nucleus occurs during β -emission neutron → proton + electron
5.2.5
Use measurements of background radiation to determine a corrected count rate and γ -radiation in electric fields and magnetic fields reference to:
- (a) kinetic energy
- (b) electric charge
5.2.5a
Use decay equations, using nuclide notation, to show the emission of α -particles, β -particles and γ -radiation from which background radiation has not been subtracted the half-life of an isotope determine which isotope is used for applications including: materials with the choice of radiations used linked to penetration and absorption gamma rays:
- (a) household fire (smoke) alarms
- (b) irradiating food to kill bacteria
- (c) sterilisation of equipment using gamma rays
- (d) measuring and controlling thicknesses of
- (e) diagnosis and treatment of cancer using

6. Space physics

1. Earth and the Solar System

6.1.1Know that the Earth is a planet that rotates on its axis, which is tilted, once in approximately of the apparent daily motion of the Sun and the periodic cycle of day and night
6.1.1a
Describe the Solar System as containing: order from the Sun dwarf planets such as Pluto and asteroids in the asteroid belt comets and natural satellites:
- (a) one star, the Sun
- (b) the eight named planets and know their
- (c) minor planets that orbit the Sun, including
- (d) moons, that orbit the planets
- (e) smaller Solar System bodies, including
6.1.2Know that the Earth orbits the Sun once in approximately 365 days and use this to explain the periodic nature of the seasons
6.1.2a
Know that, in comparison to each other, 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, to include: clouds of gas and dust formation of an accretion disc continued:
- (a) the model’s dependence on gravity
- (b) the presence of many elements in interstellar
- (c) the rotation of material in the cloud and the
6.1.3Know 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
6.1.3a
Know that the strength of the gravitational field mass of the planet from the planet increases:
- (a) at the surface of a planet depends on the
- (b) around a planet decreases as the distance
6.1.4Define average orbital speed from the equation where r is the average radius of the orbit and T is the orbital period; recall and use this equation
6.1.4aCalculate the time it takes light to travel a significant distance such as between objects in the Solar System
6.1.5Know that the Sun contains most of the mass of the Solar System and this explains why the planets orbit the Sun
6.1.6Know that the force that keeps an object in orbit around the Sun is the gravitational attraction of the Sun 6.2.1 The Sun as a star
6.1.7Know 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
6.1.8Analyse and interpret planetary data about orbital distance, orbital duration, density, surface temperature and uniform gravitational field strength at the planet’s surface
6.1.9Know 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
6.1.10Know that an object in an elliptical orbit travels faster when closer to the Sun and explain this using the conservation of energy

2. Stars and the Universe

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 and ultraviolet regions of the electromagnetic spectrum
6.2.1a
State that: stars Milky Way much further away from the Earth than the Sun is from the Earth in light-years, where one light-year is the distance travelled in (the vacuum of) space by light in one year:
- (a) galaxies are each made up of many billions of
- (b) the Sun is a star in the galaxy known as the
- (c) other stars that make up the Milky Way are
- (d) astronomical distances can be measured
6.2.1bKnow 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
6.2.2Know 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
6.2.2aKnow that one light-year is equal to 9.5 × 10 m
6.2.2bDescribe redshift as an increase in the observed wavelength of electromagnetic radiation emitted from receding stars and galaxies
6.2.3
Describe the life cycle of a star: gas and dust that contain hydrogen and increasing in temperature as a result of its internal gravitational attraction inward force of gravitational attraction is balanced by an outward force due to the high temperature in the centre of the star fuel for the nuclear reaction more massive stars expand to form red supergiants when most of the hydrogen in the centre of the star has been converted to helium planetary nebula with a white dwarf star at its centre forming a nebula containing hydrogen and new heavier elements, leaving behind a neutron star or a black hole at its centre stars with orbiting planets:
- (a) a star is formed from interstellar clouds of
- (b) a protostar is an interstellar cloud collapsing
- (c) a protostar becomes a stable star when the
- (d) all stars eventually run out of hydrogen as
- (e) most stars expand to form red giants and
- (f) a red giant from a less massive star forms a
- (g) a red supergiant explodes as a supernova,
- (h) the nebula from a supernova may form new
6.2.3aKnow that the light emitted from distant galaxies appears redshifted in comparison with light emitted on the Earth
6.2.4Know that redshift in the light from distant galaxies is evidence that the Universe is expanding and supports the Big Bang Theory
6.2.5Know that microwave radiation of a specific frequency is observed at all points in space around us and is known as cosmic microwave background radiation (CMBR)
6.2.6Explain 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
6.2.7Know 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
6.2.8Know that the distance of a far galaxy d can be determined using the brightness of a supernova in that galaxy
6.2.9Define the Hubble constant H as the ratio of the speed at which the galaxy is moving away from the Earth to its distance from the Earth; recall and use the equation
6.2.10Know that the current estimate for H is 2.2 × 10 per second
6.2.11Know that the equation 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