Version 1.0: 0309 abc General ertificate of Education Physics 651 Specification P0 Waves, Fields and Nuclear Energy Mark Scheme 009 examination - January series
Mark schemes are prepared by the Principal Examiner and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation meeting attended by all examiners and is the scheme which was used by them in this examination. The standardisation meeting ensures that the mark scheme covers the candidates responses to questions and that every examiner understands and applies it in the same correct way. s preparation for the standardisation meeting each examiner analyses a number of candidates scripts: alternative answers not already covered by the mark scheme are discussed at the meeting and legislated for. If, after this meeting, examiners encounter unusual answers which have not been discussed at the meeting they are required to refer these to the Principal Examiner. It must be stressed that a mark scheme is a working document, in many cases further developed and expanded on the basis of candidates reactions to a particular paper. ssumptions about future mark schemes on the basis of one year s document should be avoided; whilst the guiding principles of assessment remain constant, details will change, depending on the content of a particular examination paper. Further copies of this Mark Scheme are available to download from the Q Website: www.aqa.org.uk opyright 009 Q and its licensors. ll rights reserved. OPYRIGHT Q retains the copyright on all its publications. However, registered centres for Q are permitted to copy material from this booklet for their own internal use, with the following important exception: Q cannot give permission to centres to photocopy any material that is acknowledged to a third party even for internal use within the centre. Set and published by the ssessment and Qualifications lliance. The ssessment and Qualifications lliance (Q) is a company limited by guarantee registered in England and Wales (company number 3673) and a registered charity (registered charity number 7333). Registered address: Q, Devas Street, Manchester M15 6EX Dr Michael resswell Director General
Physics P0 - Q GE Mark Scheme 009 January series Instructions to Examiners 1 Give due credit to alternative treatments which are correct. Give marks for what is correct; do not deduct marks because the attempt falls short of some ideal answer. Where marks are to be deducted for particular errors specific instructions are given in the marking scheme. Do not deduct marks for poor written communication. Refer the script to the wards meeting if poor presentation forbids a proper assessment. In each paper candidates may be awarded up to two marks for the Quality of Written ommunication in cases of required explanation or description. Use the following criteria to award marks: marks: andidates write legibly with accurate spelling, grammar and punctuation; the answer containing information that bears some relevance to the question and being organised clearly and coherently. The vocabulary should be appropriate to the topic being examined. 1 mark: andidates write with reasonably accurate spelling, grammar and punctuation; the answer containing some information that bears some relevance to the question and being reasonably well organised. Some of the vocabulary should be appropriate to the topic being examined. 0 marks: andidates who fail to reach the threshold for the award of one mark. 3 n arithmetical error in an answer should be marked E thus causing the candidate to lose one mark. The candidate s incorrect value should be carried through all subsequent calculations for the question and, if there are no subsequent errors, the candidate can score all remaining marks (indicated by ticks). These subsequent ticks should be marked E (consequential error). With regard to incorrect use of significant figures, normally two, three or four significant figures will be acceptable. Exceptions to this rule occur if the data in the question is given to, for example, five significant figures as in values of wavelength or frequency in questions dealing with the Doppler effect, or in atomic data. In these cases up to two further significant figures will be acceptable. The maximum penalty for an error in significant figures is one mark per paper. When the penalty is imposed, indicate the error in the script by SF and, in addition, write SF opposite the mark for that question on the front cover of the paper to obviate imposing the penalty more than once per paper. 5 No penalties should be imposed for incorrect or omitted units at intermediate stages in a calculation or which are contained in brackets in the marking scheme. Penalties for unit errors (incorrect or omitted units) are imposed only at the stage when the final answer to a calculation is considered. The maximum penalty is one mark per question. 6 ll other procedures, including the entering of marks, transferring marks to the front cover and referrals of scripts (other than those mentioned above) will be clarified at the standardising meeting of examiners. 3
Physics P0 - Q GE Mark Scheme 009 January series GE Physics, Specification, P0, Waves, Fields and Nuclear Energy Section This component is an objective test for which the following list indicates the correct answers used in marking the candidates responses. Keys to Objective Test Questions 1 D B 3 D B 5 6 7 8 9 11 1 13 D 1 B 15 Section B Question 1 shm is defined by acceleration displacement (from mean position)! explanation of sign! (e.g. acceleration is in opposite direction to displacement, or is always directed towards a fixed point, or towards equilibrium position) 1 0.6 T = π = π! g gives T = 1.60 (s)! 9.81 time for bob to travel from to = T = 0.0 s! max speed of bob v max = π f! = 3 π 1.60! (= 0.173 m s -1 ) max E K of bob (= ½ m v max ) = ½ 1.5-0.173! 7 =.() - J! [or max E K of bob = E P gained in moving from to B! (180 - Δh) Δh = [or 60 = + (60 Δh) ] gives Δh = 1.5 (mm)! max E K of bob (= mgδh) = 1.5-9.81 1.5-3! =.() - J!] Total 9
Physics P0 - Q GE Mark Scheme 009 January series Question c wavelength of blue light λ = f = 3.00 6.5 8 1 =.6-7 (m)! fringe width = λd s.6 7 0.75 = 0.60 3! (= 5.78 - m) no of lines in 5 mm length = 5.0 5.78 3 = 8.65: allow 8 or 9! repeat same steps as in for red light (or by proportion) (λ = 6.5-7 m, fringe width = 8.15 - m) giving no of lines in 5 mm length = 6.13: allow 6 or 7! monochromatic 1 single colour bright (and dark) fringes (or lines or bands)! equally spaced! 3 parallel to each other! intensity of fringes decreases outwards from centre of pattern! white light max 5 fringes are (black and) white in central region! 6 coloured fringes away from central region! [ coloured fringes is an alternative to 5 and 6 for! 6 only] 7 outer edges red and inner edges blue! 8 overlapping of colours causes fringes to merge and become indistinct! Total 8 Question 3 1 (net) electron flow is round circuit (from Q) to P! (rate of) electron flow (or current) decreases (as t increases) [or repulsion from electrons already on P makes flow decrease]! 3 electron flow (or current) ceases when pd across PQ = emf (or.0 V)! electron flow rate (or current) decreases exponentially! 5 pd across capacitor increases! 6 pd across resistor decreases! 7 V R + V =.0 V (or = emf)! 8 V increases to.0 V and V R decreases to 0 V! 9 V (or V R ) changes exponentially with time! max 5 5
Physics P0 - Q GE Mark Scheme 009 January series E (= ½ V ) = ½ 50-6.0! = 1.0 - J! line drawn as a curve of increasing gradient that starts at (0, 0)! parabolic shape, checked from points on line, which reaches.0 V! Total 9 Question four factors to list (in any order): flux density of magnetic field speed of movement (not time to remove) area of coil (not magnetic field) initial angle between plane of coil and magnetic field factors listed!! or 3 factors listed! area of coil = 60-3 35-3 =.1-3 (m )! ΔB 80 = Δt 50 3 3 = 1.6 (T s -1 )! ΔΦ ΔB = =.1-3 1.6! = 3.3(6) -3 W b s -1! Δt Δt [alternatively, the four marking points in this calculation are: area of coil! change of flux! rate of change of flux! answer with unit!] 6 induced emf ΔΦ = N = 8 3.36-3! = 0.16(1) V! Δ t Total 8 6
Physics P0 - Q GE Mark Scheme 009 January series Question 5 Δm = (1.00783).0060! (= 0.087 u) energy released = 0.087 931.3 = 6.(7) MeV! rate of production by Sun = π (1.50 11 ) 1350! = 3.8() 6 (W)! (c) use of ΔE = (Δm)c! gives Δm = 3.8 (3 8 ) 6 =.() 9 kg s -1! [answers in kg min -1, kg h -1, kg day -1 or u s -1 etc would be acceptable] energy released when one He nucleus is produced! = 6.7 6 1.60-19 =.7-1 (J)! energy required per day = 3.8 6 3600 = 3.30 31 (J)! no of He nuclei produced per day = 3.30.7 31 1 = 7.7(3) (day -1 )! 5 [alternatively, mass decrease of Sun per day =. 9 3600 = 3.66 1 (kg)! mass decrease per He nucleus formed = 0.087 1.66-7 =.77-9 (kg)! no of nuclei formed per day = = 7.6(7) (day -1 )!] 3.66.77 1 9 [or award three equivalent marking points for any of the many alternative ways of reaching this final answer] Total 9 Quality of Written ommunication Q and/or Q3 7