9702_s12_ms_52

Please download to get full document.

View again

of 4
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information Report
Category:

Creative Writing

Published:

Views: 6 | Pages: 4

Extension: PDF | Download: 0

Share
Related documents
Description
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS GCE Advanced Subsidiary Level and GCE Advanced Level MARK SCHEME for the May/June 2012 question paper for the…
Transcript
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS GCE Advanced Subsidiary Level and GCE Advanced Level MARK SCHEME for the May/June 2012 question paper for the guidance of teachers 9702 PHYSICS 9702/52 Paper 5 (Planning, Analysis and Evaluation), maximum raw mark 30 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes must be read in conjunction with the question papers and the report on the examination. ã Cambridge will not enter into discussions or correspondence in connection with these mark schemes. Cambridge is publishing the mark schemes for the May/June 2012 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. Page 2 Mark Scheme: Teachers’ version Syllabus Paper GCE AS/A LEVEL – May/June 2012 9702 52 1 Planning (15 marks) Defining the problem (3 marks) P1 v is the independent variable and θ is the dependent variable or vary v and measure θ. [1] P2 Keep the (shape and) size/volume/surface area/mass of balloon/helium constant [1] Do not credit ‘same balloon’. P3 Keep the temperature (air/helium/balloon) constant. [1] Methods of data collection (5 marks) M1 Labelled diagram of apparatus: balloon, string fixed and method of producing wind. Method of producing wind to be approximately horizontal to balloon. [1] M2 Suspend mass from balloon. [1] M3 Method to change wind speed, e.g. change setting, variable power supply/resistor/change distance from fan. [1] M4 Method to measure wind speed, e.g. wind speed indicator/detector, anemometer [1] M5 Method to measure angle – use protractor or rule for measurements for trigonometry methods. This must be shown correctly on diagram or explained in text. [1] Method of analysis (2 marks) A1 Plot a graph of tan θ against 1/v2. [1] A2 Relationship valid if straight line through origin [1] Safety considerations (1 mark) S1 Avoid the moving blades of the fan (safety screen, switch off when changing experiment); goggles to avoid air stream into eye. [1] Additional detail (4 marks) D1/2/3/4 Relevant points might include [4] 1 Large wind speed to produce measurable deflection/large cross-sectional area of balloon. 2 Additional detail on measuring angle e.g. use a large protractor, projection method. 3 tan θ = h/l. 4 Measuring air speed at point where balloon is positioned. 5 Adjust height of fan so that air flow is horizontally aligned to the balloon. 6 Reason for adding mass to increase stability/deflection. 7 Keep windows shut/air conditioning switched off/use of wind tunnel to avoid draughts. 8 Wait for the balloon to become stable. Do not allow vague computer methods. [Total: 15] © University of Cambridge International Examinations 2012 Page 3 Mark Scheme: Teachers’ version Syllabus Paper GCE AS/A LEVEL – May/June 2012 9702 52 2 Analysis, conclusions and evaluation (15 marks) Part Mark Expected Answer Additional Guidance (a) A1 1 T T Gradient = Allow equivalent, e.g. 2 µ 4µ (b) T1 1/L / m–1 or (1/L) / m–1 Allow 1/L (m–1), 1/L / 1/m, 1/L (1/m) T2 1.83 or 1.835 Values must correspond to table. A mixture of 2.08 or 2.083 3 s.f. and 4 s.f. is allowed 2.35 or 2.353 2.50 or 2.500 2.82 or 2.817 3.13 or 3.125 U1 From ± 0.01 or ± 0.02, to ± 0.05 Allow more than one significant figure. (c) (i) G1 Six points plotted correctly Must be within half a small square. Penalise ‘blobs’ (more than half a small square). Ecf allowed from table. U2 All Error bars in 1/L/m–1 plotted Check second and last point for accuracy. correctly. Must be accurate within half a small square. (ii) G2 Line of best fit If points are plotted correctly then lower end of line should pass between (1.8, 250) and (1.8, 254) and upper end of line should pass between (3.18, 450) and (3.2, 448). Allow ecf from points plotted incorrectly – examiner judgement. G3 Worst acceptable straight line. Line should be clearly labelled or dashed. Steepest or shallowest possible Should pass from left of top error bar to right line that passes through all the of bottom error bar or right of top error bar to error bars. left of bottom error bar. Mark scored only if all error bars are plotted. (iii) C1 Gradient of best fit line The triangle used should be at least half the length of the drawn line. Check the read offs. Work to half a small square. Do not penalise POT. (Should be about 140) U3 Uncertainty in gradient Method of determining absolute uncertainty Difference in worst gradient and gradient. (d) (i) C2 Value of µ using gradient µ = 7.5/gradient2 Gradient must be used. (Should be about 0.00037 or 3.7 × 10–4) C3 kg m–1 or N Hz–2 m–2 Allow other correct units e.g. N s2 m–2 or Pa s2 or N (Hz m)–2 (ii) U4 10% + 2 × percentage Check working. Must be larger than 10%. uncertainty in gradient © University of Cambridge International Examinations 2012 Page 4 Mark Scheme: Teachers’ version Syllabus Paper GCE AS/A LEVEL – May/June 2012 9702 52 (e) C4 r given to 2 or 3 s.f. and Allow 1.2 to 2 s.f. in the range 1.15 × 10–4 to Penalise 1 s.f. or 3 s.f. 1.18 × 10–4 U5 (d)(ii) / 2 Check working if not (d)(ii) / 2 [Total: 15] Uncertainties in Question 2 (c) (iii) Gradient [U3] Uncertainty = gradient of line of best fit – gradient of worst acceptable line Uncertainty = ½ (steepest worst line gradient – shallowest worst line gradient) (d) (ii) [U4] ∆m Percentage uncertainty = 10 + 2 m max T 2 −µ Percentage uncertainty = 4 × min m × 100 µ min T 2 −µ Percentage uncertainty = 4 × max m × 100 µ (e) (ii) [U5] max r − r Percentage uncertainty = × 100 r min r − r Percentage uncertainty = × 100 r © University of Cambridge International Examinations 2012
Recommended
9702_m16_ms_52

9702_m16_ms_52

4 pages

9702_w15_ms_52

9702_w15_ms_52

4 pages

9702_w13_ms_52

9702_w13_ms_52

4 pages

9702_w12_ms_52

9702_w12_ms_52

4 pages

9702_w11_ms_52

9702_w11_ms_52

4 pages

9702_w10_ms_52

9702_w10_ms_52

4 pages

9702_s16_ms_52

9702_s16_ms_52

6 pages

9702_s15_ms_52

9702_s15_ms_52

4 pages

9702_s14_ms_52

9702_s14_ms_52

5 pages

9702_s13_ms_52

9702_s13_ms_52

4 pages

9702_s12_qp_52

9702_s12_qp_52

8 pages

9702_s12_ms_35

9702_s12_ms_35

4 pages

9702_s12_ms_41

9702_s12_ms_41

7 pages

View more...
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks