P4.2f explain how this effect is used in an alternator to generate a.c., and in a dynamo to generate d.c. 113-6 96-7 115-8, 234-5 P4.2g explain how the effect of an alternating current in one circuit, in inducing a current in another, is used in transformers 121-3 100-1 123-5, 238-9 P4.2h explain how the of the potential differences across the two depends on the ratio of the numbers of turns in each 121-3 100-1 123-5, 238-9 P4.2i apply the equations linking the potential differences and numbers of turns in the two coils of a transformer 121-3 100-1 123-5, 238-9 P4.2j explain the action of the microphone in converting the pressure variations in sound waves into variations in current in electrical circuits, and the reverse effect as used in loudspeakers and headphones To include an understanding of how dynamic microphones work using electromagnetic induction 120 100 122, 238 assesses content from Topics P5-P8 and P9 Topic P5: Waves in matter P5.1 Wave behaviour P5.1a describe wave motion in terms of amplitude, wavelength, frequency and period 93-5 80 95-7, 218 P5.1b define wavelength and frequency 93-5 80 95-7, 218 P5.1c describe and the relationship between these and the wave velocity 93-5 80 95-7, 218 P5.1d apply formulae relating velocity, frequency and wavelength (M1c, M3c) M1c, M3c 93-5 80 95-7, 218 P5.1e describe differences between transverse and longitudinal waves To include direction of travel and direction of vibration 93-5 79 95-7, 217 P5.1f show how changes, in velocity, frequency and wavelength, in transmission of waves from one medium to another, are inter-related 98-9 79-80 100-1, 217-9 P5.1g describe the effects of reflection, transmission, and absorption of at material interface examples such as ultrasound and sonar 98-9 82-4 100-1, 220-2 P5.1h describe, with examples, processes which convert wave disturbances between sound waves and vibrations in solids 98-9 83-4 100-1, 221-2
P5.2h describe how ultra-violet waves, X-rays and gamma-rays can have hazardous effects, notably on human bodily tissues 100-2 85-6 102-4, 223-4 P5.2i explain, in qualitative terms, how the differences in velocity, absorption and reflection between different types of waves in solids and liquids can be used both for detection and for exploration of structures which are hidden from direct observation, notably in our bodies To include the use of infra-red, X-rays, gamma and ultrasound as an alternative in medical imaging 100-2 85-6 102-4, 223-4 P5.2j recall that radio waves can be produced by, or can themselves induce, oscillations in electrical circuits 101 85 103, 223 P5.3 Wave interactions P5.3a recall that different substances may absorb, transmit, refract, or reflect electromagnetic waves in ways that vary with wavelength 100-2 85-6 102-4, 223-4 P5.3b explain how some effects are related to differences in the velocity of electromagnetic waves in different substances 100-2 85-6 102-4, 223-4 P5.3c use ray diagrams to illustrate reflection, refraction and the similarities and differences between convex and concave lenses (qualitative only) To include how the behaviour of convex and concave lenses determine how they may be used, for example, to correct vision 96-7 82 98-9, 220 P5.3d construct two-dimensional ray diagrams to illustrate reflection and refraction (qualitative only –equations not needed) 96-7 82 98-9, 220 P5.3e explain how colour is related to differential absorption, transmission and reflection To include specular reflection and scattering 106-7 89-90 108-9, 227-8 P6: Radioactivity P6.1 Radioactive emissions P6.1a recall that atomic nuclei are composed of both protons and neutrons, that the nucleus of each element has a characteristic positive charge 49-50 42-3 51-2, 180-1 P6.1b recall that atoms of the same elements can differ in nuclear mass by having different numbers of neutrons 49-50 42-3 51-2, 180-1
P8.1d explain methods of measuring human reaction times and recall typical results 88-9 74-5 90-1, 212-3 P8.1e explain the factors which affect the distance required for road transport vehicles to come to rest in emergencies and the implications for safety To include factors that affect thinking and braking distance and overall stopping distance 88-9 74-5 90-1, 212-3 P8.1f estimate how the distances required for road vehicles to stop in an emergency, varies over a range of typical speeds 88-9 74-5 90-1, 212-3 P8.1g explain the dangers caused by large decelerations 88-9 74-5 90-1, 212-3 P8.1h estimate the forces involved in typical situations on a public road 88-9 74-5 90-1, 212-3 P8.1i estimate, for everyday road transport, the speed, accelerations and forces involved in large accelerations 88-9 74-5 90-1, 212-3 P8.2 Powering Earth P8.2a describe the main energy sources available for use on Earth, compare the ways in which they are used and distinguish between renewable and non-renewable sources To include fossil fuels, nuclear fuel, bio-fuel, wind, hydro-electricity, tides and the Sun 21-3 18-9 23-5, 156-7 P8.2b explain patterns and trends in the use of energy resources To include the changing use of different resources over time 21-3 18-9 23-5, 156-7 P8.2c recall that, in the national grid, electrical power is transferred at high voltages from power stations, and then transferred at lower voltages in each locality for domestic use 37 32 39, 170 P8.2d recall that step-up and step-down transformers are used to change the potential difference as power is transferred from power stations 37 32 39, 170 P8.2e explain how the national grid is an efficient way to transfer energy 37 32 39, 170 P8.2f link the potential differences and numbers of of a transformer to the power transfer involved; relate this to the advantages of power transmission at high voltages 37 32 39, 170