Cambridge IGCSE Physics 0625 — 2010 May/June Paper 2 · Variant 1

This document consists of 18 printed pages and 2 blank pages. DCA (SHW 00380 1/09) 20403/6 © 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. * 2 4 2 5 8 6 3 1 0 1 * PHYSICS 0625/21 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 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 1 Imagine that you live beside a busy road. One of your neighbours thinks that many of the vehicles are travelling faster than the speed limit for the road. You decide to check this by measuring the speeds of some of the vehicles. (a) Which two quantities will you need to measure in order to find the speed of a vehicle, and which instruments would you use to measure them? quantity measured instrument used [4] (b) State the equation you would use to calculate the speed of the vehicle. If you use symbols, state what your symbols mean. [1] (c) One lorry travels from your town to another town. The lorry reaches a top speed of 90 km / h, but its average speed between the towns is only 66 km / h. (i) Why is the average speed less than the top speed? … … … [1] (ii) The journey between the towns takes 20 minutes. Calculate the distance between the towns. distance = … km [3] [Total: 9]

3 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 2 A helical spring is hung from the edge of a bench top, as shown in Fig. 2.1. 100 0 29.8 cm bench top 100 0 62.8 cm spring pin metre rule load = 5.5 N Fig. 2.1 Before the load is hung on the spring, the pin points to the 29.8 cm mark on the metre rule. When a load of 5.5 N is hung on the spring, the pin points to 62.8 cm. (a) Calculate the extension of the spring. extension = … cm [2] (b) The law relating extension to load is given by the equation load = constant × extension. (i) Calculate the numerical value of the constant. constant = … [2] (ii) Suggest a suitable unit for the constant. … [1] [Total: 5]

4 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 3 (a) Fig. 3.1 represents the energy into and out of a machine. input energy I wasted energy W useful output energy U Fig. 3.1 Write down the equation linking I, U and W. … [1] (b) An electric motor and a pulley in a warehouse are being used to lift a packing case of goods from the ground up to a higher level. This is shown in Fig. 3.2. cable pulley chains pallet ground packing case electric motor Fig. 3.2 The packing case of goods, the chains and the pallet together weigh 850 N. (i) State the value of the tension force in the cable when the load is being lifted at a steady speed. tension force = … N [1]

5 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (ii) When the load is just leaving the floor, why is the force larger than your answer to (b)(i)? … … [1] (iii) The warehouse manager wishes to calculate the useful work done when the load is lifted from the ground to the higher level. Which quantity, other than the weight, does he need to measure? … [1] (iv) Which further quantity does the manager need to know, in order to calculate the power required to lift the load? … [1] (c) How does the electrical energy supplied to the electric motor compare with the increase in energy of the load? Answer by completing the sentence below. The electrical energy supplied to the motor is ……………………………… the increase in energy of the load. [1] [Total: 6]

6 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 4 (a) A musical note is being produced by a loudspeaker connected to a signal generator. A person is listening to the note, as shown in Fig. 4.1. signal generator amplitude frequency Fig. 4.1 By adjusting the controls on the signal generator, the amplitude and the frequency of the note from the loudspeaker can each be changed. The person moves to a position further away from the loudspeaker. (i) State what, if anything, happens to 1. the pitch of the sound heard, … 2. the loudness of the sound heard. … [2] (ii) What adjustment, if any, should be made to the two controls so that the sound heard in the new position is the same as in the original position? frequency control … amplitude control … [2]

7 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (b) Fig. 4.2 shows a girl standing some distance from a rock face. She has a bell in her hand. rock face Fig. 4.2 The girl rings the bell once. After a short time the sound of the bell reaches her again. (i) Why did the sound return to her? … [1] (ii) Why was there a short time delay before the girl heard the second sound? … [1] [Total: 6]

8 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 5 Fig. 5.1 shows a child’s toy. It is made out of wood, in the shape of a bird. The toy includes a metal weight stuck to the tail. When placed on a metal rod, the toy balances in equilibrium. metal weight metal rod Fig. 5.1 (a) On Fig. 5.1, mark with the letter X a possible position for the centre of mass of the toy. [1] (b) The metal weight falls off the tail. (i) On Fig. 5.1, mark with the letter Y a possible new position for the centre of mass. [1] (ii) What happens to the toy immediately after the metal weight falls off? … … … [2] [Total: 4]

9 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 6 (a) Fig. 6.1 shows a beaker in which coffee is served at an airport kiosk. section through beaker layer of corrugated cardboard stuck to a layer of smooth cardboard, with air trapped between them Fig. 6.1 Fig. 6.2 The beaker itself is made of two layers of cardboard, as shown in section in Fig. 6.2. It has a thin plastic lid. (i) State two sources of heat loss that are reduced by the lid. 1. … 2. … [2] (ii) State two reasons why the layer of corrugated cardboard stops the fingers of the person holding the beaker from becoming uncomfortably hot. 1. … 2. … [2] (b) (i) State the meaning of the term thermal capacity. … … [2] (ii) Another airport kiosk serves coffee in pottery mugs. The mugs all have the same internal dimensions but some have a high thermal capacity and some have a low thermal capacity. When hot drinks are poured into the mugs, the temperature of the drink always drops because of the thermal energy absorbed by the mug. State which mug, high thermal capacity or low thermal capacity, causes the least fall in temperature of the hot drink, and explain why. mug … explanation … [2] [Total: 8]

10 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 7 The electric lamp in Fig. 7.1 has “240 V, 100 W” marked on it. Its filament is a coiled coil of fine tungsten wire, as shown in Fig. 7.2. Fig. 7.1 Fig. 7.2 (a) (i) To give out white light, the filament has to reach a very high temperature. Suggest why having the filament as a coiled coil helps to achieve this high temperature. … … … [1] (ii) If your hand is close to the lamp when it is switched on for a few seconds, you can feel warmth from the lamp but the glass will remain cool. By what method has the thermal energy reached your hand? Tick one box. conduction convection evaporation radiation [1]

11 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (b) (i) The markings on the lamp give electrical information about the lamp when it is operating normally. State the value of 1. the normal operating potential difference across the lamp, … 2. the power of the lamp. … [2] (ii) When the lamp is working normally, its resistance is 576 . Calculate the current in the lamp. current = … [4] [Total: 8]

12 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 8 Fig. 8.1 shows how an image is formed by a converging lens. O F2 F1 I 24 cm 10 cm 8cm Fig. 8.1 (a) State the value of the focal length of the lens. focal length = … cm [1] (b) The object O is moved a small distance to the left. State two things that happen to the image I. 1. … 2. … [2] (c) Points F1 and F2 are marked on Fig. 8.1. (i) State the name we give to these two points. … [1] (ii) On Fig. 8.1, draw the ray from the top of the object which passes through F2. Continue your ray until it meets the image. [4] [Total: 8]

13 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 9 (a) A warning on the packaging of a light switch purchased from an electrical store reads SAFETY WARNING This push-button switch is not suitable for use in a washroom. Lights in washrooms should be operated by pull-cord switches. (i) Explain why it might be dangerous to use a push-button switch in a washroom. … … … [2] (ii) Why is it safe to use a pull-cord switch in a washroom? … … [1] (b) An electric heater, sold in the electrical store, has a current of 8 A when it is working normally. The cable fitted to the heater has a maximum safe current of 12 A. Which of the following fuses would be most suitable to use in the plug fitted to the cable of the heater? Tick one box. 5 A 10 A 13 A 20 A [1] (c) The cable for connecting an electric cooker is much thicker than the cable on a table lamp. (i) Why do cookers need a much thicker cable? … … [1] (ii) What would happen if a thin cable were used for wiring a cooker to the supply? … … [1] [Total: 6]

14 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 10 A transformer has 500 turns in both its primary and its secondary coils. It is connected to a 240 V mains supply. There are 4 possible connections to the secondary, labelled W, X, Y and Z on Fig. 10.1. P W X Y Z 240 V primary coil 500 turns secondary coil 500 turns Fig. 10.1 Between W and X there are 300 turns. Between X and Y there are 175 turns. Between Y and Z there are 25 turns. (a) A person wishes to run a 12 V electric bell, using the transformer. Between which two of the labelled terminals should the bell be connected? Show your working. bell connected between terminal … and terminal … [4] (b) State the voltage between terminals W and Z. … [1]

15 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use (c) State the name given to the part labelled P and the material from which it is made. name … material … [2] (d) Why are the coils normally made from copper wire? … … [1] [Total: 8]

16 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use 11 Fig. 11.1 shows apparatus being used to project a visible spectrum onto a screen, using a lamp with a white-hot filament. P Q A B visible spectrum screen glass prism glass lens filament lamp (white light source) Fig. 11.1 (a) State two things that happen to the white light as it passes through surface PQ of the prism. 1. … 2. … [2] (b) What colour light will be seen at (i) edge A of the spectrum, … (ii) edge B of the spectrum? … [2] (c) A thermometer with a blackened bulb is moved very slowly across the screen. (i) On Fig. 11.1, mark using a cross (×) the position where the thermometer will show its largest reading. [2] (ii) What type of radiation would cause this high reading? … [1] [Total: 7]

17 0625/21/M/J/10 © UCLES 2010 [Turn over For Examiner’s Use 12 (a) A scientist, who is also an antiques collector, buys an old watch at an antiques market. The figures on the dial of the watch are painted with a type of luminous paint that is radioactive. In his laboratory, he puts the watch close to a radiation detector and then places sheets of different materials in the gap between them, as shown in Fig. 12.1. watch sheet radiation detector counter Fig. 12.1 The results of his investigation are given in the following table. material effect sheet of paper no observable change in count rate 1 mm thick sheet of aluminium a noticeable decrease in the count rate 1 mm thick sheet of lead considerable decrease in the count rate but still above background (i) From this information, deduce the type or types of radiation escaping from the watch. … … … [2] (ii) The back of the watch is made of steel 1 mm thick. State one reason why there would be a health hazard when wearing this watch. … … … [1]

18 0625/21/M/J/10 © UCLES 2010 For Examiner’s Use (b) Radioactive materials are stored in a cupboard. (i) Which of the symbols shown in Fig. 12.2 is used on the door of the cupboard to warn of the radiation hazard? Tick one box. Fig. 12.2 [1] (ii) State one other safety precaution that should be taken when storing the radioactive substances in the cupboard. … … [1] [Total: 5]

19 0625/21/M/J/10 © UCLES 2010 BLANK PAGE

20 0625/21/M/J/10 © UCLES 2010 BLANK PAGE 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 Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.

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 0625/21 Paper 21 (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 21 © UCLES 2010 Notes about Mark Scheme Symbols and 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 figures specified 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 21 © UCLES 2010 1 (a) distance tape measure, trundle wheel, metre wheel B1, B1 OR laser measure NOT (metre) rule time stopwatch/clock IGNORE just watch/clock IGNORE just chronometer B1, B1 (b) speed = distance/time any arrangement, words or symbols B1 OR just distance/time IGNORE magic triangles (c) (i) idea of acceleration/deceleration OR some distance at lower speed/lorry stops B1 (ii) distance = speed × time in this form only, words, letters or numbers C1 66 × 20 OR 66 × ⅓ OR 66 × 20/60 C1 22 (km) c.a.o. condone 0.33 used to give appropriate answer A1 [9] 2 (a) 62.8 – 29.8 C1 33.0 (cm) OR 33 (cm) A1 (b) (i) 5.5 = constant × 33 e.c.f. C1 0.166 recurring e.c.f. ignore units accept 1/6 or 0.16 or 0.166 or 0.167 or 0.17 or 0.2 NOT 0.20 A1 (ii) N/cm OR N/m OR n/cm OR n/m seen in (ii) nothing else – mark independently of (i) B1 [5] 3 (a) I = U + W accept words or mixture of words/symbols B1 (b) (i) 850 (N) B1 (ii) force needed to accelerate load/get it started OR if forces equal, then no movement B1 (iii) height OR distance (use ✓ +  = 0 for extras) B1 (iv) time (use ✓ +  = 0 for extras) B1 (c) greater than OR > OR stronger accept “double” etc B1 [6]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 21 © UCLES 2010 4 (a) (i) 1 nothing OR no change B1 2 quieter/softer OR loudness less/decreases B1 (ii) frequency control: none OR no adjustment no e.c.f. B1 amplitude control: increase (amplitude) no e.c.f. allow turn clockwise/to right B1 (b) (i) echo OR reflection (of sound) OR bounced (back) B1 (ii) idea of sound taking a finite time to travel OR idea of sound doesn’t travel infinitely fast IGNORE sound has to travel to rock face and back B1 [6] 5 (a) X marked anywhere, above or below, on vertical anywhere through rod B1 (b) Y marked anywhere to right of X, but not beyond R.H. tip of parrot B1 (c) idea of topples/falls/loses balance C1 topples clockwise/to the right/to the front/forwards A1 [4] 6 (a) (i) radiation evaporation any 2 B1, B1 convection (ii) cardboard/it is a poor conductor/(good) insulator air is trapped OR air is a poor conductor/(good) insulator any 2 B1, B1 reduced surface in contact with fingers (b) (i) heat/energy to raise/lower/change temperature of a body OR heat/energy to heat up a body B1 by 1 °C OR by 1K OR unit temp B1 (ii) low thermal capacity M1 less heat needed to raise temperature OR absorbs less heat A1 [8]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 21 © UCLES 2010 7 (a) (i) idea of heat concentrated in a small space OR lots of wire in small space OR to get required resistance in a small place B1 (ii) radiation B1 (b) (i) mark 1 and 2 together 240 and 100 in correct order B1 V and W in correct order B1 (ii) I = V/R OR I = W/V in any form, symbols or numbers C1 240/576 OR 100/240 C1 0.416 recurring, accept 0.4 or 0.416 or 0.417 or 0.41 or 0.42 NOT 0.40 C1 A OR a OR amp(s) OR ampere(s) A1 [8] 8 (a) 10 (cm) B1 (b) gets smaller NOT gets lower B1 gets closer to lens/moves to left/moves closer to F1 B1 (c) (i) principal focus/foci OR focal/focus point(s) NOT focal length NOT focus B1 (d) (ii) (ignore any arrows) ray drawn from top of object, through F2, to lens must pass through the stroke indicating F2 B1 single refraction clearly at centre line OR two appropriate refractions at surfaces B1 travels parallel to axis after lens, by eye must be drawn with ruler B1 reaches top of image B1 [8] 9 (a) (i) water conducts/water lowers resistance B1 could get a shock (however expressed) B1 (ii) idea of cord insulating you from electricity OR cord not a conductor OR idea of separates you from the electrics/live parts B1 (b) 10A ticked B1 (c) (i) large(r) current NOT more electricity B1 (ii) it/insulation/cable would overheat/melt OR cause fire NOT blow up/damaged NOT fuse blows B1 [6]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0625 21 © UCLES 2010 10 (a) V1/V2 or N1/N2 or V1/N1 or V2/N2 in any form Allow full credit for use C1 substitution correct and seen of 25 turns to give 12V, M1 25 turns with working seen A1 Y and Z (either order) B1 (b) 240 (V) B1 (c) core B1 iron NOT steel B1 (d) good conductor OR low resistance OR to reduce heating OR for high efficiency IGNORE good/bad conductor of heat B1 [8] 11 (a) refraction OR slows down OR changes speed/wavelength OR bends NOT reflaction or refrection B1 dispersion OR divides/splits into colours/wavelengths/frequencies B1 (b) (i) red If red and violet interchanged, B1 allow B1 only (ii) violet NOT blue NOT purple B1 (c) (i) X at or above top of visible spectrum M1 middle of X clearly above top of visible spectrum but no more than twice height of the letter A from top of visible spectrum, by eye A1 (ii) infra-red OR IR OR ir OR heat/thermal (radiation) B1 [7] 12 (a) (i) beta, gamma –1 e.e.o.o. B2 (ii) idea that radiation (from watch) can enter the body B1 (b) (i) bottom left box ticked –1 e.e.o.o. B1 (ii) locked cupboard OR lock (it) OR storage in lead/suitable containers IGNORE protective clothing/tongs etc B1 [5]