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* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Jan 2013 P1 Higher Jan 2013 P1 Higher Jan 2013 P2 Higher Jan 2013 P2 Higher June 2012 P1 Higher June 2012 P1 Higher June 2012 P1 Higher June 2012 B2 Higher Jan 2012 P1 Higher Jan 2012 P1 Higher P1 Specimen P1 Specimen P1 Specimen P2 Specimen P2 Specimen P3 Specimen P3 Specimen P3 Specimen E-AQA Mark Scheme P1 long answer questions M1. (a) (i) to compare mobile phone usage between the two groups 1 (ii) enough data to indicate relationships or reduce effect of anomalous data 1 (b) (i) ethical 1 (ii) research may be biased (in favour of companies) 1 negative effects on health may not get published accept negative effects on health may be played down 1 (iii) it allows people to easily identify lower risk phones 1 and this allows people to make a more informed choice accept and this allows a comparison to be made 1 [7] M2. (a) because black is a good absorber of radiation 1 there will be a faster transfer of energy allow the temperature of the water rises faster 1 (b) 16 800 000 allow 1 mark for substitution into correct equation ie 100 × 4200 × 40 2 (c) 7 allow ecf from part (b) 1 (d) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. No relevant content. 0 marks There is a brief description of the advantages and disadvantages of using solar energy to heat the water rather than using an electric immersion heater, including either advantages or disadvantages from the examples below. Level 1 (1-2 marks) There is a description of some of the advantages and disadvantages of using solar energy to heat the water rather than using an electric immersion heater, with at least one advantage and one disadvantage from the examples below. Level 2 (3-4 marks) There is a clear, balanced and detailed description of the advantages and disadvantages of using solar energy to heat the water rather than using an electric immersion heater, with a minimum of two advantages and two disadvantages from the examples below. Level 3 (5-6 marks) examples of the points made in the response advantages accept specific examples of polluting gases • a renewable energy source • energy is free • does not pollute the atmosphere • no fuel is burnt • energy can be stored (in the water) disadvantages accept unreliable energy source • only available in daylight hours • availability fluctuates • insufficient hours of sunlight in some countries • average low intensity in some countries [11] M3. coal has chemical energy when burnt heat/energy produced longest used to boil water/make steam sequence used to turn turbine(s) which now have ke turbine(s) turn generator(s) (where (ke) transferred electrical energy) (or electrical energy produced ) any 5 for 1 mark each [5] ## (NB. Answers referring to planets to gain zero marks Answers in terms of stars – deduct 1 mark) A B C light from (most) other galaxies shows a red-shift this means that these galaxies and our own galaxy are moving apart / Universe expanding the red-shift of more distant galaxies is greater D E this means that the further apart galaxies are the faster they are moving away from each other the relationship is proportional so this means that in the past they all set out from the same point each properly related point for 1 mark [5] M5. ideas that • direct solar radiation will provide enough energy to heat the (specially designed) buildings during the period Oct-Mar / summer • solar cells will produce plenty of electricity in Oct-Mar / summer (when wind generators produce little) • a couple of wind generators will produce all electricity needed (for all but heating) Apr-Oct / winter • number required makes wind generators unsuitable for heating / buildings • no solar energy in June and July / little in winter • solar / wind have little effect on environment • or cause no air pollution • solar and wind complement each other • or together provide energy all year • fuel / gas / diesel can provide energy all the time / at any time • fuel / gas / diesel needed for transport • fuel / gas / diesel needed for heating in winter • diesel has to be imported • diesel likely to freeze • gas wouldn’t have to be imported • drilling for gas difficult / harms environment • but atmospheric pollution a global rather than local matter so any produced in Antarctic doesn’t matter much (deduct 1 mark (to minm. zero) for incorrect claims about destroying ozone layer) • gas produces less carbon dioxide (for the same energy released) than diesel* • gas produces less sulphur dioxide (for the same energy released than diesel* (* these ideas met by candidates in Q.16 so must be allowed, though not required) any ten for 1 mark each [10] E-AQA P2 Long Answer Questions Mark Scheme M1. (a) Y and Z both required, either order 1 same number of protons 1 (b) fusion correct order only 1 energy 1 (c) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. No relevant content. 0 marks There is a brief description of the life cycle of a star like the sun. Level 1 (1–2 marks) There is some description of the life cycle of a star like the sun. Level 2 (3–4 marks) There is a clear and detailed description of the life cycle of a star like the sun. Level 3 (5–6 marks) examples of the physics points made in the response to score full marks either the term red giant or white dwarf must be used • gases and dust pulled together by gravity • nuclear fusion begins • when forces are balanced star is stable • expands • cools • becomes a red giant do not accept red supergiant • shrinks • temperature rises • glows much brighter • becomes a white dwarf any mention of supernova negates a mark any mention of black hole negates a mark individual points must be linked in a correct sequence [10] M2. (a) converted into helium accept helium created accept converted into heavier elements accept used up in nuclear fusion / to produce energy do not accept any reference to burning 1 (b) turns / expands into a red giant contradictions negate mark 1 contracts and explodes or becomes a supernova 1 may form a (dense) neutron star or (if enough mass shrinks to) form a black hole accept forms a neutron star and (then) a black hole 1 Quality of written communication correct points must be in sequence 1 (c) (i) supernova or remains of an earlier star ignore super nebula 1 (ii) younger or not formed at the time of the Big Bang 1 [7] M3. Quality of written communication: One mark for using correct scientific sequence : gravity → fusion → balance 1 any four from • (dust and gas) pulled together by gravity • (star formed when) it is hot enough accept (as mass is pulled together) it gets very hot • hydrogen (and helium) nuclei fuse • (these nuclear fusion reactions) release the energy / heat / light (which is radiated by stars) • energy causes expansion • gravitational pull is balanced by the expansion (force) 4 [5] M4. (a) materials produced when earlier stars exploded accept the Sun is a second generation star accept formed from nebulae 1 (b) Quality of written communication: 1 mark for correct sequencing balanced forces → expansion → contraction / explosion 1 any five from gravity pulling matter together accept idea that a star is very massive so its force of gravity is very strong high temperatures that create expansion forces nuclear fusion releases energy that causes the very high temperatures these forces balance star expands greatly since expansion is greater than gravity accept fuel runs out forms a red giant give no further marks if red giant → white dwarf, red dwarf etc collapses inwards and explodes outwards called a supernova neutron star may form leaves a small, dense object (a black hole) accept nothing can escape from it 5 [7] M5. ideas that • formed from dust/gases • pulled together by gravity • massive so very large gravitational forces (pulling inwards) • hydrogen → helium / fusion releases energy [not fission or just ‘nuclear’] • high temperature creates high pressure (pushing outwards) • long period when forces balance • then expands → red giant / red star • then contracts to (dense) white dwarf / white star [credit if massive enough / more massive than sun, red giant → supernova → (very dense) neutron star but do not accept w.r.t. Sun itself] [The whole of the (non bracketed part of) each idea must be present in some appropriate for in of words for each mark to be credited. To gain more than a single mark ideas must also be in correct sequence and/or appropriately related.] any six 1 mark each [6] E-AQA P3 Long Answer Questions Mark Scheme M1. Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. No relevant content. 0 marks There is a brief explanation of how a current is caused to flow in the starter motor circuit. Level 1 (1–2 marks) There is some explanation of how a current is caused to flow in the starter motor circuit. Level 2 (3–4 marks) There is a clear and detailed explanation of how a current is caused to flow in the starter motor circuit. Level 3 (5–6 marks) examples of the physics points made in the response current flows through the coil / electromagnet magnetic field produced accept electromagnet switches on (short side of) iron bar attracted to electromagnet contacts pushed together (by iron bar) starter motor circuit completed current flows through starter motor or p.d. across starter motor [6] M2. (a) (i) X at the centre of the lifebelt measuring from the centre of X, allow 2 mm tolerance in any direction 1 (ii) any two from: if X is on vertical line below the hanger (but not at centre) can gain the first point only below the point of suspension accept ‘(vertically) below Y’ at the centre (of the lifebelt) accept ‘in the middle’ (because) the lifebelt / it is symmetrical or (because) the mass / weight is evenly distributed 2 (b) Nm or newton metre(s) accept Newton metre(s) do not accept any ambiguity in the symbol ie NM, nM or nm 1 750 (moment) = force (perpendicular) distance (between line of action and pivot) or (moment) = 500 1.5 gains 1 mark 2 (c) Quality of written communication: for 2 of the underlined terms used in the correct context 1 any three connected points from: low(er) centre of mass / gravity or centre of mass / gravity will be close(r) to the wheels / axle / ground (more) stable or less unstable less likely to fall over accept ‘less likely to overturn’ do not accept ‘will not fall over’ the turning effect / moment (of the weight of case) is less or so less effort is needed to hold the case ignore references to pulling the case so the pull on her arm is less 3 [10] M3. electromagnet becomes stronger (not becomes magnetic) iron moves left – implied OK plunger goes up push switch goes to off or circuit broken unless plunger moves down for 1 mark each [4] M4. Quality of written communication: One mark for correct sequencing. bolt out plunger up switch off / circuit broken 1 any five from • high current flows • electromagnet is stronger • the iron bolt is pulled out • the plastic plunger moves up • the switch is lifted / open / off accept circuit is broken • no current flowing • to re-set the plunger must be pushed down 5 [6]