abc Mark Scheme Physics 6456 Specification B General Certificate of Education Fields and their Applications 2008 examination - June series

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1 Vesion 1.: 88 abc Geneal Cetificate of Education Physics 6456 Specification B PHB5 Fields and thei Applications Mak Scheme 8 examination - June seies

2 Mak schemes ae pepaed by the Pincipal Examine and consideed, togethe with the elevant questions, by a panel of subject teaches. This mak scheme includes any amendments made at the standadisation meeting attended by all examines and is the scheme which was used by them in this examination. The standadisation meeting ensues that the mak scheme coves the candidates esponses to questions and that evey examine undestands and applies it in the same coect way. As pepaation fo the standadisation meeting each examine analyses a numbe of candidates scipts: altenative answes not aleady coveed by the mak scheme ae discussed at the meeting and legislated fo. If, afte this meeting, examines encounte unusual answes which have not been discussed at the meeting they ae equied to efe these to the Pincipal Examine. It must be stessed that a mak scheme is a woking document, in many cases futhe developed and expanded on the basis of candidates eactions to a paticula pape. Assumptions about futue mak schemes on the basis of one yea s document should be avoided; whilst the guiding pinciples of assessment emain constant, details will change, depending on the content of a paticula examination pape. Futhe copies of this Mak Scheme ae available to download fom the AQA Website: Copyight 8 AQA and its licensos. All ights eseved. COPYRIGHT AQA etains the copyight on all its publications. Howeve, egisteed centes fo AQA ae pemitted to copy mateial fom this booklet fo thei own intenal use, with the following impotant exception: AQA cannot give pemission to centes to photocopy any mateial that is acknowledged to a thid paty even fo intenal use within the cente. Set and published by the Assessment and Qualifications Alliance. The Assessment and Qualifications Alliance (AQA) is a company limited by guaantee egisteed in England and Wales (company numbe 6447) and a egisteed chaity (egisteed chaity numbe 174). Registeed addess: AQA, Devas Steet, Mancheste M15 6EX D Michael Cesswell Diecto Geneal

3 NOTES Lettes ae used to distinguish between diffeent types of maks in the scheme. M indicates OBLIGATORY METHOD MARK This is usually awaded fo the physical pinciples involved, o fo a paticula point in the agument o definition. It is followed by one o moe accuacy maks which cannot be scoed unless the M mak has aleady been scoed. C indicates COMPENSATION METHOD MARK This is awaded fo the coect method o physical pinciple. In this case the method can be seen o implied by a coect answe o othe coect subsequent steps. In this way an answe might scoe full maks even if some woking has been omitted. A indicates ACCURACY MARK These maks ae awaded fo coect calculation o futhe detail. They follow an M mak o a C mak. B indicates INDEPENDENT MARK This is a mak which is independent of M and C maks. e.c.f is used to indicate that maks can be awaded if an eo has been caied fowad (e.c.f. must be witten on the scipt). This is also efeed to as a tansfeed eo' o 'consequential making'. Whee a coect answe only (c.a.o.) is equied, this means that the answe must be as in the Making Scheme, including significant figues and units. c.n.a.o. is used to indicate that the answe must be numeically coect but the unit is only penalised if it is the fist eo o omission in the section (see below). Only one unit penalty (u.p.) in this pape unless thee is a mak allocated specifically fo giving a coect unit in the making. Note that the unit is only penalised in the final answe to the question. Only one significant figue penalty (s.f.) in this pape. Allow o s.f. unless othewise stated. s.f. penalties include ecuing figues and factions fo answes. Maks should be awaded fo coect altenative appoaches to numeical question that ae not coveed by the making scheme. A coect answe fom woking that contains a physics eo (PE) should not be given cedit. Examines should contact the Team Leade o Pincipal Examine fo confimation of the validity of the method, if in doubt. Quality of Witten Communication Befoe accessing maks fo the Quality of Witten Communication (QWC) a candidate must fist scoe a minimum of one mak fo the physics that is being communicated this will allow access to 1 mak fo QWC. If the candidate scoes moe maks fo physics (a minimum of two o thee depending upon the total mak fo that pat of the question) then this will allow access to maks fo QWC. Good QWC: the answe is fluent/well agued with few eos in spelling, punctuation and gamma Poo QWC: the answe lacks coheence o spelling, punctuation and gamma ae poo Vey Poo QWC: the answe is disjointed, with significant eos in spelling, punctuation and gamma 1 Max

4 GCE Physics, Specification B, PHB5, Fields and thei Applications Question 1 v = π T 1 π o ( πf and f = ) o (v = ω and ω = ) T T coect substitution v = π v = π (m s -1 ) (given to o moe s.f.) o GMm mv = o (F = GMm and F = mv ) o v = GM coect substitution v = (m s -1 ) (given to o moe s.f.) GMm 1 = mv o (Ep = substitution coect v = GMm 1 and Ek = mv ) o v = GM condone powe of 1 eo fo adius 1 (15) m s -1 (u.p.) (c) pv = nrt (o equation with values substituted) n = ( ) 1-4 (mol) molecules leave the suface easily o molecules have velocities which ae highe than the escape speed o light molecules will escape 4 Pluto exets a low gavitational foce o has a low gavitational field stength o gases/substances may have liquefied/solidified tempeatue on Pluto is (vey) low B! Total 1 4

5 Question λ =.69/57 (. 1 7 ) seen (maybe seen in A = λn) 9.5 (9.46) 1 18 Bq moles of cabon = /6 1 = mol o mass = moles 14 g clealy stated o 1 mol = 14 g 5 o ealises that activity fom is needed mass of cabon 14 pe sec =.1 g o. g ( g o kg) allow e.c.f. fom C + β + ve (condone no Z/A fo anti neutino) N 1 symbols with antineutino shown Z coect fo C, N and β A coect fo C, N and β (c) λ =.69/57 o e.c.f. fo use of same incoect λ fom.5 =.75e -λt -1 (5-58) (yeas) c.a.o. the estimated (appoximate) age is too high boat is younge than has been estimated estimated age should be lowe (than (c) ) the effect would lowe the estimated/appoximate age assumption of oiginal activity (of.75 in equation) is too high o fewe atoms have (actually) decayed than has been assumed o activity change is (actually) lowe than has been assumed o mathematical altenatives A (in the estimate in (c) ) is too high ln (A/A ) is too low (ln A /A is too high) so t is too high o the actual A was lowe than that assumed in (c) ln (A/A ) should be highe (ln A /A should be lowe) so t should be lowe 5 Total 1 5

6 Question similaity foce obeys invese squae law 1 (allow F ) o potential/potential enegy vaies as 1/ diffeence gavitational foce only attactive/neve epel o electic field can be attactive o epulsive o gavitational potentials ae only negative/neve positive o electic potentials can be positive o negative E p = Qq 4πε o E p = kqq 1 and k = 4πε coect substitution E p = 79 ( ) 4π ( ) ( ) (J) ( o moe sig figs necessay) KE change = = J use of E k = ½ mv (may use with wong enegy substituted) 7 (iii) v = 6.9 (6.86) 1 6 (m s -1 ) assume m s -1 if no unit given same initial path path deflects though geate angle and geate closest distance of appoach (c) gold nucleus ecoils/is epelled/gains enegy/gains momentum mass of gold nucleus (vey) much geate than mass of alpha paticle gold nucleus has much lowe speed than the alpha paticle o little enegy tansfe to the gold nucleus M1 Total 1 6

7 Question 4 coect substitutions to find initial and final mass o numbe of fissions possible/numbe of U atoms in 5 5 g = 6 1 = o mass change pe disintegation =. (.18) 1-8 kg total mass change = kg (.46 g) clea attempt to calculate mass of potons and neutons mass diffeence = kg E = mc (J) divides thei answe to by 5 o divides thei answe to by J e.c.f. thei.7 (.66) (7.47) MeV = unless woking shown 6 (c) any label E (fo enegy extaction) mentions coolant liquid (sodium o wate) o gas (CO ) emoves enegy/heat fom the coe coolant/hot gas/liquid then passes though a system/heat exchange to poduce steam steam used to dive tubines/geneatos powe contol mentions contol/boon ods neutons have to be absobed/fewe fission neutons lowe ods educes powe output M1 M1 max 6 At least maks fo physics + Good QWC At least maks fo physics + Poo QWC 1 At least maks fo physics + Vey Poo QWC 1 mak fo physics + sufficient attempt + Good o Poo QWC 1 1 mak fo physics + insufficient attempt o Vey Poo QWC No maks fo physics o Vey Poo QWC max Total 17 7

8 Question 5 identifies inteaction between electic cuent/moving ions/chage and magnetic field mention of (Flemings) left hand ule o foce at ight angles to field and cuent foce on ions/wate (molecules) to left/backwads equal and opposite foce on the boat o motion of boat conseves momentum 4 E = V/d o 5/.5 seen E = 14 (14) V m -1 o N C -1 (u.p.) R = ρl/a o R =..5/1. R =.58 Ω o R not calculated but substituted in next equation 6 l = V/R o 5/thei R (c) A one u.p. in (c) thust (fom one system) = BIL thust (fom one system) = 86.5 = 9 (9) 6 N powe = Fv o thei 7.5 e.c.f. 7 kw if coect e.c.f. (iii) two fom intenal enegy of the wate 7 o (l R)/powe dissipation in o heating of wate wate gives KE tubulence fiction/viscosity effects between wate and system enegy losses/dissipated in coils/cicuits of magnet losses due to electolysis (d).4 (m s - ) e.c.f. fom 5 (c) coect cuvatue stating at thei acceleation Total 19 8

9 Question 6 diection of the foce on a positively chaged paticle o diection in which a positive chage acceleates o diection in which a positive chage moves when placed in the field o moves fom est in the field 1 diagam showing adial field lines (at least fou) aow shown fom anode to cathode Total Question 7 ev = ½ mv o E = ev and E = ½ mv v = ev m (coect substitution in a coect equation) e.g = ½ v.8 (.75) 1 7 (m s -1 ) 6 Bev = mv / coect substitution with = mm condone incoect powe of mt o mwb m - (u.p.) c.a.o. any electons need to obit at a lage adius (fom equation Bev = mv /), v (o v / must be constant) if B (m and e) constant voltage must incease to incease velocity M1 Total 9 9

10 Question 8 electons oscillate aound/in the cavity/pimay coil o altenating/changing cuent in the cavity/pimay coil an altenating/changing cuent poduces an altenating/changing magnetic flux/field thee is a (changing/altenating) magnetic flux/field linking the coupling/seconday coil induced emf/cuent in (coupling/seconday) coil 4 At least maks fo physics + Good QWC At least maks fo physics + Poo QWC 1 At least maks fo physics + Vey Poo QWC 1 mak fo physics + sufficient attempt + Good o Poo QWC 1 1 mak fo physics + insufficient attempt o Vey Poo QWC No maks fo physics o Vey Poo QWC max Total 6 Question 9 photon enegy = hf = J o numbe of photons = o photon enegy hf photon numbe = 11/ = ( ) 1 6 Total 1

11 Question 1 wavelength = c/f; c = fλ.1 (.1) m sketch dawn with 6 loops (e.c.f. fo thei wavelength) condone sine wave athe than loops with zeo at X and Y antinode indicated (lette H) on o nea XY H shown on vetical line though antinode most photons/maximum enegy dissipated at the antinode/whee amplitude is geatest o enegy amplitude M Total 5 Question 11 doo/inside lined with metal doo fitted closely (to stop escape of waves) inside cooked by conduction (of enegy fom hotte oute pats) with liquids convection cuents occu Total 4 11

Version 1.0. klm. General Certificate of Education June Mathematics. Mechanics 2B. Mark Scheme

Version 1.0. klm. General Certificate of Education June Mathematics. Mechanics 2B. Mark Scheme Vesion.0 klm Geneal Cetificate of Education June 00 Mathematics MMB Mechanics B Mak Scheme Mak schemes ae pepaed by the Pincipal Examine and consideed, togethe with the eleant questions, by a panel of