Cambridge IGCSE Physics 0625 — 2010 May/June Paper 2 · Variant 2

This document consists of 21 printed pages and 3 blank pages. DCA (SHW 00379 1/09) 20865/5 © UCLES 2010 [Turn over UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education 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. DO NOT WRITE IN ANY BARCODES. Answer all questions. You may lose marks if you do not show your working or if you do not use appropriate units. Take the weight of 1 kg to be 10 N (i.e. acceleration of free fall = 10 m / s2). At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. * 9 5 2 2 9 8 8 0 8 8 * PHYSICS 0625/22 Paper 2 Core May/June 2010 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. www.XtremePapers.com

2 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use 1 Five identical steel balls are measured with a rule graduated in cm, as shown in Fig. 1.1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 cm wooden block Fig. 1.1 (a) Use Fig. 1.1 to find the diameter of one ball. diameter of ball = … cm [2] (b) What instrument would be used to measure the mass of a ball? … [1] (c) Another ball has a volume of 9.0 cm3 and a mass of 72 g. Calculate the density of this ball. density = … [4] [Total: 7]

3 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 2 (a) Fig. 2.1 shows a space probe, far out into space, where there is no atmosphere. It is moving at a constant speed in the direction shown by the arrow. rocket motors Fig. 2.1 Is a force necessary to keep the probe moving like this? Tick one box. yes no If your answer is “yes”, draw an arrow on the diagram to show this force. [1] (b) Fig. 2.2 shows the space probe just after the rocket motors are fired. exhaust gases Fig. 2.2 State what effect this has on the space probe. … … [2]

4 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use (c) Later into its mission, the space probe is brought back into the Earth’s atmosphere again, with no rockets working. Suggest two effects that the atmosphere has on the space probe. 1. … 2. … [2] [Total: 5]

5 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 3 (a) Here is a list of some energy resources which might be used to generate electricity. Put a tick in the box alongside any of these which relies on a fuel being consumed. oil hydroelectricity nuclear fission wind waves [2] (b) Here is a list of devices which convert energy from one form to another. battery, electric motor, gas lamp, gas fire, generator, loudspeaker, microphone Which of these is designed to convert (i) chemical energy into light energy, … (ii) electrical energy into mechanical energy, … (iii) sound energy into electrical energy? … [3] [Total: 5]

6 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use 4 (a) Fig. 4.1 shows end views of the walls built by two bricklayers. A B soil reinforced concrete foundation reinforced concrete foundation Fig. 4.1 Which wall is the least likely to sink into the soil, and why? … … … … [2] (b) Fig. 4.2 shows two horizontal squares P and Q. Q P Fig. 4.2 The atmosphere is pressing down on both P and Q. (i) Name two quantities that would need to be known in order to calculate the atmospheric pressure on square P. 1. … 2. … [2]

7 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (ii) The area of P is four times that of Q. Complete the following sentences. 1. The atmospheric pressure on P is ……………………………… the atmospheric pressure on Q. 2. The force of the atmosphere on P is ……………………………… the force of the atmosphere on Q. [3] [Total: 7]

8 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use 5 Fig. 5.1 shows a device called a thermostat, which is being used to control the temperature of the air in a room. brass strip temperature control screw contacts X Y insulator power supply heater Fig. 5.1 X and Y are strips of two different metals, joined together along their length. Together they are called a bimetallic strip. X expands more than Y for the same temperature rise. (a) The temperature rises and the bimetallic strip bends. State (i) which way the bimetallic strip bends, … [1] (ii) what happens to the contacts, … [1] (iii) what happens to the current in the circuit, … [1] (iv) what adjustment could be made to this thermostat, in order to increase the temperature at which the thermostat operates. … … [1]

9 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (b) Fig. 5.2 shows how the temperature of the water in a tank would rise if it were heated continuously, starting with water at a temperature of 0 °C. 0 0 time / minutes temperature / °C 10 20 30 40 50 60 70 10 20 30 40 50 60 70 80 Fig. 5.2 The thermostat controlling the temperature of the water switches off the heater current when the temperature rises above 50 °C. (i) Use Fig. 5.2 to determine how long the water is heated before the thermostat operates. time = … minutes [1]

10 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use (ii) The heater supplies energy at the rate of 2000 W. Calculate how much thermal energy is supplied to the water before the thermostat switches off the heater. energy = … J [3] [Total: 8]

11 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 6 (a) Fig. 6.1 illustrates a sound wave travelling through the air. direction of wave travel Fig. 6.1 (i) On Fig. 6.1, mark clearly the direction in which the air particles are moving. [1] (ii) Use Fig. 6.1 to measure the wavelength of the sound wave. wavelength = … cm [1] (iii) The pitch of the sound wave is raised. State how the sound wave pattern would differ from that shown in Fig. 6.1. … … [1] (b) Fig. 6.2 shows a section through a series of waves on water. direction of wave travel Fig. 6.2 (i) On Fig. 6.2, mark clearly the direction in which the water molecules are moving. [1] (ii) From Fig. 6.2, measure the wavelength of the water wave. wavelength = … cm [1] (iii) The amplitude of the water waves is increased. State how the appearance of the water waves would differ from that shown in Fig. 6.2. … … [1] [Total: 6]

12 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use 7 (a) A ray of light passes through one surface of a glass prism at right angles to the surface, as shown in Fig. 7.1. ray of light 45° 45° A Fig. 7.1 (i) State why the ray is not deviated as it passes through the surface into the glass at A. … … [1] (ii) On Fig. 7.1, use a ruler to help you draw the rest of the path of the ray, until it has emerged again into the air. [3] (b) Fig. 7.2 shows a periscope that uses two plane mirrors. mirror A mirror B Fig. 7.2 (i) On Fig. 7.2, clearly mark the angle of incidence i and the angle of reflection r at mirror A. [1]

13 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (ii) State the equation linking i and r. [1] (iii) In the space below, use a ruler to redraw the periscope, but using prisms like that in Fig. 7.1 instead of mirrors at A and B. [2] [Total: 8]

14 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use 8 (a) Fig. 8.1 shows a circuit containing a 6 V lamp, two switches and a 6 V motorcycle battery. The lamp has a resistance of 10  when it is glowing normally. S1 S2 6 V 6 V, 10  Fig. 8.1 How can the lamp be made to light up at normal brightness? Tick the box alongside any action which will do this. close S1 only close S2 only close both S1 and S2 [1] (b) Fig. 8.2 shows a similar circuit, but the switches are arranged in parallel. S1 S2 6 V, 10 X 6 V Fig. 8.2 How can the lamp be made to light up at normal brightness? Tick the box alongside any action which will do this. close S1 only close S2 only close both S1 and S2 [2]

15 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (c) The lamp is now connected to a 12 V car battery, as shown in Fig. 8.3. S 12V 6 V, 10  Fig. 8.3 State why it would not be wise to close switch S. … … [1] (d) Resistor R is connected in series with the lamp, as shown in Fig. 8.4. S 6 V, 10  R 12 V Fig. 8.4 (i) State what value R must have, in order to enable the lamp to have 6 V across it when S is closed. resistance = …  [1] (ii) With this resistor and the lamp in series, calculate the current in the circuit. current = … [4] [Total: 9]

16 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use 9 Fill in the gaps in the sentences below, using only appropriate words from the following list. Do not use any word more than once. charge, current, few, many, potential difference, resistance Insulators are materials which possess very ……………………………… free electrons. Because of this, when a ……………………………… is applied across an insulator, the electric ……………………………… in it is very small. The ……………………………… of a piece of insulator is likely to be very high. [3] [Total: 3]

17 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 10 (a) (i) What is an electromagnet? … … … [1] (ii) State one very useful property of an electromagnet. … … [1] (b) An iron bar has many turns of wire wrapped around it, as shown in Fig. 10.1. The wire is connected to an alternating current supply. alternating current supply iron bar flat coil low voltage lamp Fig. 10.1 Some more wire is made into a flat coil and connected across a low voltage lamp. When the flat coil is held close to the end of the iron bar, the lamp glows. Explain why this happens. … … … … … [3]

18 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use (c) Fig. 10.2 shows a relay being used to switch an electric motor M on and off. M S core springy metal contacts A B pivot iron armature insulator coil of wire Fig. 10.2 Switch S is closed. State what happens to (i) the core, … … [1] (ii) the iron armature, … … [1] (iii) the contacts A and B. … … [1] (d) A suggestion is made that the relay would work better if the armature were made of steel instead of iron. Explain why this is not a good idea. … … [2] [Total: 10]

19 0625/22/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 11 (a) State what is meant by thermionic emission. … … [2] (b) In Fig. 11.1, a beam of cathode rays is entering the space between two charged metal plates. + – cathode rays Fig. 11.1 (i) What sort of particles make up cathode rays? Tick one box. -particles electrons neutrons protons [1] (ii) On Fig. 11.1, continue the dotted line to show the path of the cathode rays as they travel between the plates and into the space beyond the plates. [3] [Total: 6]

20 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use 12 (a) Four students attempt to define the half-life of a sample of radioactive substance. Student A Half-life is half the time for the activity of the sample to decrease to zero. Student B Half-life is half the time taken for the activity of the sample to decrease to half its original value. Student C Half-life is the time taken for the activity of the sample to decrease to half its original value. Which student has given a correct definition? … [1] (b) Fig. 12.1 shows two samples of the same radioactive substance. The substance emits -particles. Fig. 12.1 Put a tick alongside any of the following quantities which is the same for both samples. the half-life of the samples the mass of the samples the number of atoms decaying each second the number of -particles emitted per second [1]

21 0625/22/M/J/10 © UCLES 2010 For Examiner’s Use (c) A quantity of radioactive material has to be taken from a nuclear reactor to a factory some distance away. Fig. 12.2 shows the decay curve for the quantity of radioactive material. 0 0 time / hours counts / minute count rate 2 4 6 8 10 12 14 16 500 1000 1500 2000 Fig. 12.2 Just before it leaves the nuclear reactor, the count-rate from the material is 2000 counts / minute. When it arrives at the factory, the count-rate is 1000 counts / minute. (i) How long did the journey take? … hours [1] (ii) How many half-lives elapsed during the journey? … [1] (iii) The material is only useful to the factory if the activity is at least 100 counts / minute. Use Fig. 12.2 to determine how many hours of useful life the factory has from the radioactive material. useful life = … hours [2] [Total: 6]

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UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2010 question paper for the guidance of teachers 0625 PHYSICS 0625/22 Paper 22 (Core Theory), maximum raw mark 80 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. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2010 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 22 © UCLES 2010 NOTES ABOUT MARK SCHEME SYMBOLS & OTHER MATTERS B marks are independent marks, which do not depend on any other marks. For a B mark to be scored, the point to which it refers must actually be seen in the candidate's answer. M marks are method marks upon which accuracy marks (A marks) later depend. For an M mark to be scored, the point to which it refers must be seen in a candidate's answer. If a candidate fails to score a particular M mark, then none of the dependent A marks can be scored. NOTE: In this paper, note the M marks in questions C marks are compensatory method marks which can be scored even if the points to which they refer are not written down by the candidate, provided subsequent working gives evidence that they must have known it. e.g. if an equation carries a C mark and the candidate does not write down the actual equation but does correct working which shows he knew the equation, then the C mark is scored. A marks are accuracy or answer marks which either depend on an M mark, or which are one of the ways which allow a C mark to be scored. c.a.o. means "correct answer only". e.c.f. means "error carried forward". This indicates that if a candidate has made an earlier mistake and has carried his incorrect value forward to subsequent stages of working, he may be given marks indicated by e.c.f. provided his subsequent working is correct, bearing in mind his earlier mistake. This prevents a candidate being penalised more than once for a particular mistake, but only applies to marks annotated "e.c.f." e.e.o.o. means "each error or omission". brackets ( ) around words or units in the mark scheme are intended to indicate wording used to clarify the mark scheme, but the marks do not depend on seeing the words or units in brackets. e.g. 10 (J) means that the mark is scored for 10, regardless of the unit given. underlining indicates that this must be seen in the answer offered, or something very similar. un.pen. means "unit penalty". An otherwise correct answer will have one mark deducted if the unit is wrong or missing. This only applies where specifically stated in the mark scheme. Elsewhere, incorrect or missing units are condoned. OR/or indicates alternative answers, any one of which is satisfactory for scoring the marks. Spelling Be generous about spelling and use of English. If an answer can be understood to mean what we want, give credit. Significant Answers are acceptable to any number of significant figures [2, except if specified figures otherwise, or if only 1 sig. fig. is appropriate. Units Ignore units, except where a mark is specified for a particular unit. Fractions These are only acceptable where specified. Extras Ignore extras in answers if they are irrelevant; if they contradict an otherwise correct response or are forbidden by mark scheme, use right + wrong = 0 Work which has been crossed out, but not replaced, should be marked as if it had not been crossed out.

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 22 © UCLES 2010 1 (a) 16 – 4 C1 2.4 (cm) A1 (b) balance/spring balance/scales NOT weighing machine B1 (c) mass/volume OR M/V C1 72/9 C1 8 A1 g/cm3 B1 [7] 2 (a) no AND no arrow shown B1 (b) accelerates it M1 in same direction/opposite direction to exhaust gases A1 (c) slows it down ) makes it hot ) any 2 B1, B1 causes friction ) [5] 3 (a) oil B1 nuclear fission B1 (use ✓ +  = 0 for extras) (b) (i) gas lamp/fire B1 (ii) electric motor OR loudspeaker B1 (iii) microphone B1 [5] 4 (a) wall A AND bigger area B1 lower pressure (on soil) B1 (b) (i) depth/height of air/atmosphere ) density of air/atmosphere ) any 2 B1, B1 (acceleration due to) gravity ) OR weight/force of air B1 area B1 (ii) 1. same B1 2. greater C1 four times A1 [7]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 22 © UCLES 2010 5 (a) (i) to the right B1 (ii) they open B1 (iii) current stops B1 (iv) screw in control screw/rotate screw clockwise B1 (b) (i) 29 (minutes) B1 (ii) E = Pt C1 2000 × his(i) × 60 C1 3.48 × 106 (J) c.a.o. A1 [8] 6 (a) (i) longitudinal movement clearly indicated B1 (ii) 8.7–8.9 B1 (iii) idea of more waves (in same distance)/shorter wavelength, however expressed Accept shown on Fig. 6.1 B1 (b) (i) vertical movement clearly indicated B1 (ii) 2.5–2.7 B1 (iii) idea of taller waves, however expressed Accept shown on Fig. 6.2 B1 [6] 7 (a) (i) hits surface at right angles OR angle of incidence zero B1 (ii) reflection shown at second surface M1 at 45° to second surface A1 correctly through third surface e.c.f. B1 (b) (i) i and r both correctly marked B1 (ii) i = r in symbols or words NOT sin i = sin r B1 (iii) upper prism correctly positioned, by eye B1 lower prism correctly positioned, by eye B1 [8]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 22 © UCLES 2010 8 (a) close both S1 and S2 ticked B1 (b) any 1 ticked C1 all 3 ticked A1 (c) lamp would blow OR too much voltage/current B1 (d) (i) 10 (Ω) B1 (ii) I = V/R in any form, symbols or numbers C1 6/10 OR 12/20 e.c.f. from (i) C1 0.6 c.a.o. A1 A B1 [9] 9 free, potential difference, current, resistance 4 correct scores B3 2 or 3 correct scores B2 1 correct scores B1 [3] 10 (a) (i) magnet which operates when there is a current OR coil wrapped round iron bar B1 (ii) can be switched on/off OR can be made very strong OR can control its strength B1 (b) mention of magnetic field B1 change in flux linkage, however expressed OR field lines being cut etc B1 induced emf/current/electricity B1 (c) (i) magnetised B1 (ii) attracted OR magnetised B1 (iii) close B1 (d) armature becomes permanently magnetised ) wouldn’t release from core ) any 2 B1, B1 contacts always closed ) [10]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 22 © UCLES 2010 11 (a) emission of electrons/charges/charged particles B1 by means of heat B1 (b) (i) electrons ticked B1 (ii) between plates continuous upward deflection, any shape M1 smooth curve A1 after plates straight line in direction of final direction between plates (allow 1 cm of curve beyond plates, before becomes straight) B1 [6] 12 (a) student C OR the last one B1 (b) half-life ticked B1 (c) (i) 4 (hours) B1 (ii) 1 B1 (iii) 17 hours (gives 100 cpm) C1 13 (hours) A1 [6]