Cambridge A Level Physics 9702 — 2006 Oct/Nov Paper 3 · Variant 1

This document consists of 7 printed pages and 1 blank page. SPA (SJF3699/CG) T01297/2 © UCLES 2006 [Turn over UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Advanced Subsidiary Level and Advanced Level PHYSICS 9702/03 Paper 3 Practical Test October/November 2006 1 hour 15 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer the one question. You are expected to record all your observations as soon as they are made, and to plan the presentation of the records so that it is not necessary to make a fair copy of them. The working of the answers is to be handed in. Marks are mainly given for a clear record of the observations actually made, for their suitability and accuracy, and for the use made of them. Additional answer paper and graph paper should be submitted only if it becomes necessary to do so. You are reminded of the need for good English and clear presentation in your answers. At the end of the examination, fasten all your work securely together. Centre Number Candidate Number Name For Examiner’s Use

You may not need to use all of the materials provided. 1 In this experiment you will investigate how the length of a vibrating wire is affected by the tension in the wire. (a) A mass of 150 g has been suspended using a copper wire as shown in Fig. 1.1. Fig. 1.1 3 9702/03/O/N/06 [Turn over For Examiner's Use © UCLES 2006 150 g mass copper wire

4 9702/03/O/N/06 For Examiner's Use © UCLES 2006 (i) Clamp the U-shaped magnet so that the wire hangs mid-way between the pole pieces and is positioned about 25 cm below the point of suspension as shown in Fig. 1.2. Fig. 1.2 (ii) Construct the circuit shown in Fig. 1.3. A connection to the top of suspended wire should be made using a crocodile clip. Connection to the lower end of the wire may be made by placing the metal end of a plug against the wire. Fig. 1.3 ~25 cm U-shaped magnet magnet crocodile clip a.c. power supply plug

(b) (i) Adjust the position of the plug by gently sliding it up or down the wire until the wire performs large amplitude oscillations as shown in Fig. 1.4. Fig. 1.4 (ii) Measure and record the length d and calculate the tension T in the wire. The gravitational field strength g = 9.8 N kg–1. d = ……………………………………. m T = ……………………………………. N (c) Determine the percentage uncertainty in this value of d. percentage uncertainty in d = ……………………………………… 5 9702/03/O/N/06 [Turn over For Examiner's Use © UCLES 2006 d

(d) (i) Change the value of T by altering the mass and repeat (b) until you have six sets of values for d and T. Include values of √T in your table of results. (ii) Justify the number of significant figures that you have given for √T. … … … (e) (i) Plot a graph of d (y-axis) against √T (x-axis) and draw the line of best fit. (ii) Determine the gradient of the line. gradient = …………………………………………… 6 9702/03/O/N/06 For Examiner's Use © UCLES 2006

7 9702/03/O/N/06 [Turn over For Examiner's Use © UCLES 2006

(f) The formula which relates d and T is where m is the mass per unit length of the wire and f is the frequency of vibration of the wire. Use your answer from (e) (ii) and the value of f (written on a card) to determine a value for m. Include an appropriate unit with your value. m = ……………………………………. (g) State one difficulty that you had when performing the experiment and one improvement that you would make if you had to repeat the experiment. difficulty … … … improvement … … … 8 9702/03/O/N/06 For Examiner's Use © UCLES 2006 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. d = 1 2f T m

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS GCE Advanced Subsidiary Level and GCE Advanced Level MARK SCHEME for the October/November 2006 question paper 9702 PHYSICS 9702/03 Paper 3 (Practical 1), maximum raw mark 25 This mark scheme is published as an aid to teachers and students, 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. All Examiners are instructed that alternative correct answers and unexpected approaches in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills demonstrated. Mark schemes must be read in conjunction with the question papers and the report on the examination. The grade thresholds for various grades are published in the report on the examination for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the October/November 2006 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses.

Page 2 Mark Scheme Syllabus Paper GCE A/AS LEVEL - OCT/NOV 2006 9702 3 © UCLES 2006 Part (b) (ii) First value for d in range 0 to 1.0 m and correct working for T 1 (i.e. mass in kg x 9.8. Expect to see 1.47 N. Ignore sf.) Part (c) Percentage uncertainty in d (must show working) 2 ∆d = 1 mm to 5 mm (1 mark) Ratio correct and x 100 (1 mark) Part (d) (i) Readings 6 6 sets of readings in the table scores 6 marks; 5 sets then 5 marks etc. Don’t allow a set of readings where suspended mass is 0. Check a value for √T. Tick if correct. If incorrect, write in correct value and – 1. Minor help from Supervisor then – 1. Major help then – 2. Repeated readings 1 For each value of T there must be at least two values of d. Do not award this mark if all the length readings are identical for every T value. Quality of results 1 At least five points must be plotted to qualify for this mark. Judge by scatter of points about the line of best fit (all d values within ± 0.03 m of marker’s best line). Do not award this mark if the wrong graph has been plotted (i.e. the quality cannot be judged), or if there is a negative or curved trend. Do not award this mark if range of d is less than 0.20 m. Column headings 1 Apply to √T only. Expect to see √T /N1/2 or √T (N1/2) or √(T/N) etc. Consistency 1 Apply to raw values of d only. Check values by row; decimal places must be the same in every row. Part (d) (ii) Justification of sf in √T 2 Must be same as or one better than (1 mark) the sf in T or M (1 mark). ‘Raw values’ ideas get one out of two marks only. Ignore references to sf in g. Reference to decimal places scores zero.

Page 3 Mark Scheme Syllabus Paper GCE A/AS LEVEL - OCT/NOV 2006 9702 3 © UCLES 2006 Part (e) (i) Axes 1 Scales must be such that the plotted points occupy at least half the graph grid in both the x and y directions. Scales must be labelled with the quantity plotted. Ignore units. Do not allow awkward scales (e.g. 3:10, 6:10 etc). Allow reversed axes. Plotting of points 1 All points must be plotted. Check a suspect plot. Circle and tick if correct. If incorrect, show correct position with arrow, and -1. Work to half a small square. Line of best fit 1 There must be at least 5 trend points. There must be a reasonable balance of points about the line of best fit. Part (e) (ii) Determination of gradient 1 ∆ used must be greater than half the length of the drawn line; read-offs must be correct to half a small square. Part (f) Gradient equated with 1/2f√m 1 Correct method of working to give value of m, i.e. substitution of gradient value, not substitution of a point 1 Value of m in range 0.40 g m-1 to 0.60 g m-1 (or ± 0.10 g m-1 of SV) 1 Unit of m correct (e.g. g m-1). Independent mark. 1 Part (g) Difficulty (must be non-trivial, with sufficient detail). 1 e.g. difficult to measure d (accurately) e.g. wire difficult to see e.g. hard to tell when amplitude is maximum e.g. difficult to hold plug/rule still e.g. parallax error Improvement (detail may be clear from the ‘difficulty’). 1 e.g. mount ruler in stand e.g. mount plug in stand e.g. put coloured card behind wire 25 marks in total.