Cambridge IGCSE Physics 0625 — 2025 Oct/Nov Paper 4 · Variant 3

[Turn over Cambridge IGCSE™ DC (WW/CGW) 346277/3 © UCLES 2025 This document has 20 pages. Any blank pages are indicated. * 5 5 8 4 1 9 2 8 8 7 * PHYSICS 0625/43 Paper 4 Theory (Extended) October/November 2025 1 hour 15 minutes You must answer on the question paper. No additional materials are needed. INSTRUCTIONS ● Answer all questions. ● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs. ● Write your name, centre number and candidate number in the boxes at the top of the page. ● Write your answer to each question in the space provided. ● Do not use an erasable pen or correction fluid. ● Do not write on any bar codes. ● You may use a calculator. ● You should show all your working and use appropriate units. ● Take the weight of 1.0 kg to be 9.8 N (acceleration of free fall = 9.8 m / s2). INFORMATION ● The total mark for this paper is 80. ● The number of marks for each question or part question is shown in brackets [ ]. ,










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2 0625/43/O/N/25 © UCLES 2025 1 (a) A hard ball is dropped vertically downwards. Fig. 1.1 shows the speed–time graph for the ball from when it is dropped until it hits the ground. Air resistance is ignored. 0 0 0.2 0.4 0.6 0.8 1.0 2 4 6 speed m / s time / s 8 Fig. 1.1 (i) Describe the motion of the ball in Fig. 1.1. … … [1] (ii) Show that the distance travelled by the ball is 1.8 m. [2] (iii) The mass of the ball is 0.54 kg. Calculate the gravitational potential energy stored in the ball immediately before it is dropped. gravitational potential energy = … [2] * 0000800000002 * ,










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3 0625/43/O/N/25 © UCLES 2025 [Turn over (iv) Determine the kinetic energy of the ball when it has fallen half way to the ground. kinetic energy = … [1] (b) The same ball is dropped from an aeroplane. Air resistance acts on the ball. Explain how the vertical motion of the ball changes, from when it is dropped to just before it hits the ground. Use the idea of forces in your answer. … … … … … [3] (c) A soft ball is dropped by a student so that it bounces on the ground. Fig. 1.2 shows the height–time graph for the ball. The height is measured from the ground. The ball bounces four times. height m time / s A B C Fig. 1.2 Explain why the change in height of the ball between B and C is less than the change in height between A and B. … … … … [2] [Total: 11] * 0000800000003 * ,










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4 0625/43/O/N/25 © UCLES 2025 2 A cricket ball is travelling at a speed of 25 m / s horizontally through the air. The mass of the ball is 0.14 kg. A player catches the ball and the ball comes to rest. (a) Calculate the change in momentum of the ball during the catch. change in momentum = … [2] (b) The player’s hands are in contact with the moving ball for 9.7 ms. Calculate the horizontal force exerted by her hands to bring the ball to rest. force = … [3] [Total: 5] * 0000800000004 * ,










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5 0625/43/O/N/25 © UCLES 2025 [Turn over 3 (a) Fig. 3.1 shows a Sankey diagram for the power transfer in a coal‑fired power station. power input from fuel = 3400 MW power wasted in power station due to thermal energy transfers = 2200 MW power used in power station = 40 MW power used in transmission = 25 MW useful power output Fig. 3.1 (i) Show that the useful power output from the power station is approximately 1100 MW. [2] (ii) Calculate the efficiency of the power station. efficiency = … [2] (b) Describe how useful energy may be obtained from geothermal resources. … … … … … [2] [Total: 6] * 0000800000005 * ,










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6 0625/43/O/N/25 © UCLES 2025 4 (a) (i) A rectangular glass tank contains 3.0 m3 of liquid. The mass of the liquid is 2800 kg. Calculate the density of the liquid. density = … [1] (ii) A metal block is placed in the tank and it sinks to the bottom. The top surface of the block is 1.1 m below the surface of the liquid. Fig. 4.1 shows the block on the bottom of the tank. liquid metal block 0.45 m 0.30 m 1.1 m Fig. 4.1 Calculate the force exerted by the liquid on the top of the block. force on top of the block = … [4] * 0000800000006 * ,










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7 0625/43/O/N/25 © UCLES 2025 [Turn over (b) Fig. 4.2 shows part of a steel railway track. There are small gaps between sections of the rail. small gap section of rail Fig. 4.2 State why gaps are needed between the sections of rail. Explain your answer in terms of particles. statement … explanation … … [2] (c) Fig. 4.3 shows a saucepan of boiling water on the heating ring of an electric cooker. plastic handle heating ring boiling water metal pan Fig. 4.3 The handle is made from plastic. Explain why this material is suitable. … … … [2] [Total: 9] * 0000800000007 * ,










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8 0625/43/O/N/25 © UCLES 2025 5 (a) (i) Electromagnetic waves have many uses. On Fig. 5.1 draw one line from each use to the region of the electromagnetic (e‑m) spectrum it uses. Use Region of e‑m spectrum security marking gamma rays Bluetooth ultraviolet optical fibres infrared detection of cancer radio waves Fig. 5.1 [2] (ii) State one advantage of using microwaves compared with radio waves to transmit mobile (cell) phone signals. … … [1] (b) Describe the difference between transverse waves and longitudinal waves. … … … … [2] * 0000800000008 * ,










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9 0625/43/O/N/25 © UCLES 2025 [Turn over (c) Fig. 5.2 shows a simplified diagram of seismic P‑waves travelling through the Earth. The paths of the waves are curved. Seismic waves are produced by rock movements in earthquakes. P-waves liquid outer core inner core (mostly) solid mantle earthquake occurs here X Fig. 5.2 (not to scale) (i) State the type of wave that P‑waves can be modelled as. … [1] (ii) At point X, the P‑wave travels from the solid mantle to the liquid core. There is a sudden change in direction of the path of the wave. Explain the change in direction of the P‑wave at point X. … … … [2] (d) The Earth’s surface absorbs incoming radiation from the Sun and also emits thermal radiation from its surface. Over the past 50 years, scientists estimate that the average temperature of the Earth’s surface has increased by approximately 0.75 °C. Explain what is causing this average temperature rise. … … … … [2] [Total: 10] * 0000800000009 * ,










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10 0625/43/O/N/25 © UCLES 2025 6 (a) Fig. 6.1 shows a circuit which includes an LDR (light‑dependent resistor). + +5.0 V 400 Ω ı V Fig. 6.1 The LDR is in a brightly lit room. The voltmeter reads 1.8 V. (i) Calculate the current in the 400 Ω resistor. current = … [3] (ii) The light level in the room changes from bright to dark. State and explain the effect on the voltmeter reading. statement … explanation … … … … [3] * 0000800000010 * ,










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11 0625/43/O/N/25 © UCLES 2025 [Turn over (b) Fig. 6.2 shows two light‑emitting diodes (LEDs) connected in parallel in a circuit. R is a red LED and G is a green LED. The voltmeter across the LEDs shows a potential difference (p.d.) of 2.0 V. A R + +5.0 V 2.0 V ı G V Fig. 6.2 (i) Fig. 6.3 shows a current‑p.d. graph for the LEDs. 0 1.0 0 20 40 current mA 60 80 R G 2.0 3.0 p.d./ V 4.0 Fig. 6.3 Use Fig. 6.3 to determine the current in the ammeter. current = … [2] (ii) The connections to the power supply are reversed. State the reading on the ammeter. current = … [1] [Total: 9] * 0000800000011 * ,









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13 0625/43/O/N/25 © UCLES 2025 [Turn over 7 Fig. 7.1 shows a simple a.c. generator. N coil slip rings handle S coil brush front Fig. 7.1 (a) (i) Explain the function of the slip rings and brushes. … … … [1] (ii) Describe how an alternating current is generated in the lamp. … … … … … … [3] (iii) State two possible changes that cause a larger maximum current in the lamp. 1 … 2 … [2] * 0000800000013 * ,









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14 0625/43/O/N/25 © UCLES 2025 (b) Fig. 7.2 is a graph to show how the electromotive force (e.m.f.) varies with time for the coil. e.m.f. 0 A B time C D E 0 Fig. 7.2 (i) Determine how many revolutions the coil has made, from time = 0 to E. number of revolutions = … [1] * 0000800000014 * ,









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15 0625/43/O/N/25 © UCLES 2025 [Turn over (ii) Fig. 7.3 shows the end view of the position of the plane of the coil at time = 0. The coil is rotating anti‑clockwise. N S coil axis of rotation slip rings Fig. 7.3 On Fig. 7.4, draw four lines to match the coil position to the times A, B, C and D. The coil is viewed from the front. Each coil position may be used once, more than once or not at all. time label from graph coil position A B C D N S N S N S N S Fig. 7.4 [3] [Total: 10] * 0000800000015 * ,









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16 0625/43/O/N/25 © UCLES 2025 8 (a) Alpha (α) particles are directed at a very thin sheet of gold foil. The following observations provide evidence for the nuclear model of the atom. State what conclusions may be made about the model of the atom from these observations. (i) Observation: most of the particles pass straight through the foil. conclusion … … … [1] (ii) Observation: a few particles bounce back or are deflected through large angles. conclusion … … … [1] (b) Fig. 8.1 shows three beams of ionising radiation, alpha, beta and gamma, passing between two parallel plates. The plates are charged and there is a uniform electric field between them. charged plate charged plate P Q R Fig. 8.1 (i) State and explain which path P, Q or R shows a beam of alpha particles. path … explanation … … … [2] * 0000800000016 * ,









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17 0625/43/O/N/25 © UCLES 2025 [Turn over (ii) State and explain the direction of the electric field between the plates. direction … explanation … … … [1] (c) Curium‑242 is a radioactive isotope. It emits alpha particles. It has a half‑life of 160 days. After 480 days, the mass of curium‑242 in a sample is 2.4 × 10–3 g. Calculate the initial mass of curium‑242 in the sample. initial mass of curium‑242 = … [2] [Total: 7] * 0000800000017 * ,









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18 0625/43/O/N/25 © UCLES 2025 9 (a) Cosmic microwave background radiation (CMBR) can be observed in every direction in space around us. (i) State when CMBR was produced. … [1] (ii) State and explain how the wavelength of this radiation has changed since it was formed. … … … [2] (b) Table 9.1 shows data about planets in our solar system. Table 9.1 planet average radius of orbit around the Sun / 106 km time for one orbit / Earth years average surface temperature / °C Venus 108 0.62 460 Earth 150 1.00 15 Mars 228 1.90 – 65 Jupiter 778 12.00 –110 Saturn 1430 29.00 –140 (i) The orbit of Venus is approximately circular. Calculate the average orbital speed v of Venus. Give your answer in km / h. orbital speed = … km / h [3] (ii) State how the average surface temperature of a planet changes as its distance from the Sun increases. … [1] [Total: 7] * 0000800000018 * ,









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19 0625/43/O/N/25 © UCLES 2025 10 (a) Sketch a diagram to show the orbital path of a comet around the Sun. Mark the position of the Sun on your diagram using an S. [2] (b) Draw a cross on your diagram to show where the comet is travelling with the slowest speed. Label the cross L. [1] (c) Explain why the speed of a comet changes as it travels around its orbit. Use the conservation of energy in your explanation. … … … … [3] [Total: 6] * 0000800000019 * ,









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20 0625/43/O/N/25 © UCLES 2025 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. To avoid the issue of disclosure of answer‑related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. BLANK PAGE * 0000800000020 * ,










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This document consists of 20 printed pages. © Cambridge University Press & Assessment 2025 [Turn over Cambridge IGCSE™ PHYSICS 0625/43 Paper 4 Extended Theory October/November 2025 MARK SCHEME Maximum Mark: 80 Published 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 should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the October/November 2025 series for most Cambridge IGCSE, Cambridge International A and AS Level components, and some Cambridge O Level components.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 2 of 20 Generic Marking Principles These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alon gside the specific content of the mark scheme or generic level descriptions for a question. Each question paper and mark scheme will also comply with these marking principles. GENERIC MARKING PRINCIPLE 1: Marks must be awarded in line with: • the specific content of the mark scheme or the generic level descriptors for the question • the specific skills defined in the mark scheme or in the generic level descriptors for the question • the standard of response required by a candidate as exemplified by the standardisation scripts. GENERIC MARKING PRINCIPLE 2: Marks awarded are always whole marks (not half marks, or other fractions). GENERIC MARKING PRINCIPLE 3: Marks must be awarded positively: • marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate • marks are awarded when candidates clearly demonstrate what they know and can do • marks are not deducted for errors • marks are not deducted for omissions • answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the question as indicated by the mark scheme. The meaning, however, should be unambiguous. GENERIC MARKING PRINCIPLE 4: Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level descriptors.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 3 of 20 GENERIC MARKING PRINCIPLE 5: Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may be limited according to the quality of the candidate responses seen). GENERIC MARKING PRINCIPLE 6: Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thre sholds or grade descriptors in mind. Science-Specific Marking Principles 1 Examiners should consider the context and scientific use of any keywords when awarding marks. Although keywords may be present, marks should not be awarded if the keywords are used incorrectly. 2 The examiner should not choose between contradictory statements given in the same question part, and credit should not be awarded for any correct statement that is contradicted within the same question part. Wrong science that is irrelevant to the question should be ignored. 3 Although spellings do not have to be correct, spellings of syllabus terms must allow for clear and unambiguous separation fro m other syllabus terms with which they may be confused (e.g. ethane / ethene, glucagon / glycogen, refraction / reflection). 4 The error carried forward (ecf) principle should be applied, where appropriate. If an incorrect answer is subsequently used in a scientifically correct way, the candidate should be awarded these subsequent marking points. Further guidance will be included in the mark scheme where necessary and any exceptions to this general principle will be noted. 5 ‘List rule’ guidance For questions that require n responses (e.g. State two reasons …): • The response should be read as continuous prose, even when numbered answer spaces are provided. • Any response marked ignore in the mark scheme should not count towards n. • Incorrect responses should not be awarded credit but will still count towards n. • Read the entire response to check for any responses that contradict those that would otherwise be credited. Credit should not be awarded for any responses that are contradicted within the rest of the response. Where two responses contradict one another, this should be treated as a single incorrect response. • Non-contradictory responses after the first n responses may be ignored even if they include incorrect science.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 4 of 20 6 Calculation specific guidance Correct answers to calculations should be given full credit even if there is no working or incorrect working, unless the question states ‘show your working’. For questions in which the number of significant figures required is not stated, credit should be awarded for correct answers when rounded by the examiner to the number of significant figures given in the mark scheme. This may not apply to measured values. For answers given in standard form (e.g. a  10n) in which the convention of restricting the value of the coefficient (a) to a value between 1 and 10 is not followed, credit may still be awarded if the answer can be converted to the answer given in the mark scheme. Unless a separate mark is given for a unit, a missing or incorrect unit will normally mean that the final calculation mark is not awarded. Exceptions to this general principle will be noted in the mark scheme. 7 Guidance for chemical equations Multiples / fractions of coefficients used in chemical equations are acceptable unless stated otherwise in the mark scheme. State symbols given in an equation should be ignored unless asked for in the question or stated otherwise in the mark scheme.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 5 of 20 Annotations guidance for centres Examiners use a system of annotations as a shorthand for communicating their marking decisions to one another. Examiners are trained during the standardisation process on how and when to use annotations. The purpose of annotations is to inform the standard isation and monitoring processes and guide the supervising examiners when they are checking the work of examiners within their team. The meaning of annotations and how they are used is specific to each component and is understood by all examiners who mark the component. We publish annotations in our mark schemes to help centres understand the annotations they may see on copies of scripts. Note that there may not be a direct correlation between the number of annotations on a script and the mark awarded. Similarly, the use of an annotation may not be an indication of the quality of the response. The annotations listed below were available to examiners marking this component in this series. Annotations Annotation Meaning correct point or mark awarded incorrect point or mark not awarded information missing or insufficient for credit allow or accept arithmetic error incorrect point ignored while marking the rest of the response contradiction in response, mark not awarded benefit of the doubt given error carried forward applied response has not answered question

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 6 of 20 Annotation Meaning rounding error point has been noted, but no credit has been given or blank page seen error in number of significant figures transcription error response is too vague or there is insufficient detail in response answer outside the tolerance of the mark scheme used to highlight parts of an extended response used to highlight parts of an extended response mandatory mark not awarded special case

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 7 of 20 Specific Instructions for Marking 0625/Paper 4 Preparation for Marking Instructions and handbooks, for markers using RM Assessor 3 can be found at RM support portal. Marking M1. Blank pages, additional objects and marking outside the question zone. Blank pages will be attached to the first part of Q1 and should be annotated with SEEN on all scripts. Annotate any blank Additional Objects with SEEN. Link any other additional objects to the question or questions applicable. Examiners must ensure that they view the whole exam paper for each candidate. This will sometimes mean scrolling through a large zone to ensure that no working relevant to either the current or any other question is missed. Where a candidate’s answer extends beyond the marking zone, examiners must view the whole page (or link to other pages) to annotate and mark the whole answer. To view the whole page, deselect any annotation tool from the mouse, then click in the bottom right-hand corner of the marking zone where ‘view whole page’ appears. For instructions to link to other pages see above. M2. Use of Annotation stamps. Examiners annotate scripts to explain their reasons for awarding or not awarding marks, noting: • for all questions with two or more marks, it is mandatory to annotate with ticks placed to indicate where each mark is awarded. In a calculation where the final answer (A) mark is awarded all the ticks should be placed near to the final answer. • annotations and comments must never suggest or imply that a mark has been deducted e.g. –1 • annotation stamps and their uses are published with the mark scheme and visible on scripts returned to centres. It is therefo re vital that examiners apply them to scripts in a manner consistent with their published meaning. M3. Acronyms and shorthand in the mark scheme. acronym / shorthand Explanation A mark Final answer mark which is awarded for fully correct final answers including the unit. C mark Compensatory mark which may be scored when the final answer (A) mark for a question has not been awarded. B mark Independent mark which does not depend on any other mark. M mark Method mark which must be scored before any subsequent final answer (A) mark can be scored.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 8 of 20 acronym / shorthand Explanation Brackets ( ) Words not explicitly needed in an answer, however if a contradictory word / phrase / unit to that in the brackets is seen the mark is not awarded. Underlining The underlined word (or a synonym) must be present for the mark to be scored. If the word is a technical scientific term, the word must be there. / or OR Alternative answers any one of which gains the credit for that mark. Owtte Or words to that effect. Ignore Indicates either an incorrect or irrelevant point which may be disregarded, i.e., not treated as contradictory. insufficient an answer not worthy of credit on its own. CON An incorrect point which contradicts any correct point and means the mark cannot be scored. ecf [question part] Indicates that a candidate using an erroneous value from the stated question part must be given credit here if the erroneous value is used correctly here. Cao correct answer only M4. Miscellaneous Equations and formulae. • Where a C, B or M mark is available for quoting a formula or equation this can be done in any form and in words, symbols or numbers unless the mark scheme specifies otherwise. • Where a C mark is available for quoting an equation and another C mark is available for rearranging and / or substituting numbers into an equation, a candidate who only writes down the equation in the rearranged (and / or numerical) form in one step gains both C marks. Use of ecf. The mark scheme notes where ecf is applicable, in the guidance section of the final answer mark. However, it should be applied for all relevant C marks as well. Always annotate ecf if applied. See Science specific Marking point 4 above. Units. • A numerically correct final answer without a unit is awarded the final answer (A) mark if the unit is shown correctly in the candidate’s working. • A numerically correct answer with a missing or incorrect unit is not awarded the final answer (A) mark. C (B or M) marks are awarded from the candidate’s working.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 9 of 20 • Accept units with incorrect use of upper-case and lower-case symbols, e.g. pA for Pa. • Unless the mark scheme for a specific question part states otherwise, the only permitted derived units are: Unit permitted derived units W J / s or Nm / s Pa N / m2 Momentum Ns or kgm / s Impulse Ns or kgm / s J Nm • NB J is not permitted as the unit for moments. Significant Figures (SF). • Numerical answers are expected to be given to the number of significant figures given in the final answer in the mark scheme. • Answers given to more SFs than expected are awarded the A mark if, when rounded to the correct number of SF, the answer matches the mark scheme answer (allowing for ECF). • Where a final answer is given to too few SF, and the mark scheme answer has been seen in the working to at least the expected number of SF, this is penalised once only on the whole paper, with SF annotation and A mark is not awarded. Subsequent occurrences of this are ignored and the A mark is awarded. • Where a final answer is given to too few SF, and the mark scheme answer has not been seen in the working to at least the expected number of SF, this is treated as an arithmetic error, and the A mark is not awarded. Arithmetic errors and Transcription errors. Where a (probable) transcription error or arithmetic error is identified in working, ignore the error when awarding C marks. Fractions. An answer expressed as a fraction is not a numerically correct final answer unless the fraction is explicitly stated in the mark scheme. Crossed out work. When only part of an answer is crossed out the crossed-out work must be ignored. However, work which has been wholly crossed out and not replaced and can easily be read, should be marked as if it had not been crossed out. Look to see if it has been replaced on a blank page or another part of the same page before attempting to mark the crossed-out work.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 10 of 20 Marking diagrams on-screen. Differences in magnification and / or individual computer screen settings can alter the appearance of diagrams. If it is necessary to check line lengths or angles use the ruler and protractor tools provided within RM Assessor 3 to ensure consistency across all examiners. NR. (# or / key on the keyboard). Use this (instead of giving 0 marks) if the answer space for a question is completely blank or contains no readable words, figures or symbols.

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 11 of 20 Question Answer Marks 1(a)(i) constant acceleration B1 1(a)(ii) area under the graph OR ½ bh OR average speed  time B1 0.5  5.9  0.6 OR 1.77 (to ⩾ 3 sf) B1 1(a)(iii) 9.5 J A2 (Ep =) mg()h OR 0.54  9.8  1.8 C1 1(a)(iv) candidate’s 1(a)(iii) value  0.5 (2sf) A1 1(b) any three from: • (initially there is acceleration due to) an unbalanced force OR resultant force OR downward force OR weight OR gravitational force acting on the ball • as speed increases the air resistance increases • (as air resistance increases) resultant force downwards decreases OR acceleration decreases • (eventually) ball falls with constant speed when air resistance = weight OR ball falls with terminal velocity when air resistance = weight B3 1(c) (some of the) energy is: transferred to the thermal energy (store) of the ground (when ball hits ground) OR converted / transferred to thermal energy (store) of the air OR used to deform ball / transferred to the elastic energy (store) of the ball (as it contacts the ground) B1 gravitational potential energy (in the store at C) will be less (than at A) OR (ball has) less kinetic energy (in its store just after B) B1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 12 of 20 Question Answer Marks 2(a) (–) 3.5 kgm / s A2 (p =) m()u OR m{v – u} OR 0.14  {25 (– 0)} C1 2(b) 360 N A3 0.0097 (s) OR 9.7  10–3 (s) OR 3.6  10n C1 (F =) ()p / t OR 3.5 / 0.0097 C1 Question Answer Marks 3(a)(i) (wasted power =) 2200 + 40 + 25 OR 2265 OR (useful power output =) power input – wasted power B1 1140 (MW) (⩾ 3 sf) B1 3(a)(ii) 0.32 OR 32% A2 (efficiency =) {useful power output / total power input} ( 100%) OR 1100 / 3400 C1 3(b) water is pumped into the ground and heated by hot rocks OR heat from hot rocks underground is used to turn water into steam B1 steam used to heat buildings OR steam used to turn generator / turbine / produce electricity B1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 13 of 20 Question Answer Marks 4(a)(i) 930 kg / m3 A1 4(a)(ii) 1400 N A4 (∆)p = ρg(∆)h OR 930  9.8  1.1 OR 10 000 (N / m2) C1 area = length  width OR 0.45  0.30 OR 0.14 (m2) C1 (F=) p  A OR 10 000  0.14 C1 Alternative method: 1400 N A4 volume (of liquid above block) = length  width  height OR 0.45  0.30  1.1 OR 0.15 (m3) C1 mass (of liquid above block) = ρ  v OR 930  0.15 OR 140 (kg) C1 (F =) mg OR 140  9.8 C1 4(b) thermal expansion OR to prevent buckling / bending when heated B1 any one from: • particles vibrate faster • particles have greater speed / kinetic energy / momentum • vibrations (of particles) take up more space • (average) space / separation between particles increases B1 4(c) (plastic is a good) insulator / poor conductor B1 (handle) will not get too hot to touch OR reduces heat flow to hand B1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 14 of 20 Question Answer Marks 5(a)(i) all four correct = 2 marks; any two correct = 1 mark security marking gamma rays Bluetooth ultraviolet optical fibres infrared detection of cancer radio waves B2 5(a)(ii) any one from: • only require a short aerial / antenna • can pass through the atmosphere / ionosphere to satellites • can transmit large amounts of data at high speeds / high rate of data transmission B1 5(b) any two from: transverse: • oscillations / vibrations are at right angles to direction of propagation • medium not required / can travel through a vacuum (for e-m wave) • have crests / peaks and troughs longitudinal: • oscillations / vibrations are parallel to direction of propagation • medium is required • have rarefactions and compressions B2 5(c)(i) longitudinal B1 5(c)(ii) refraction B1 any one from: • change in speed of the wave • change in density of the medium B1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 15 of 20 Question Answer Marks 5(d) increase in carbon dioxide / greenhouse gases (in the atmosphere) OR increase in methane / water vapour (in the atmosphere) B1 any one from: prevents / reduces (re-emitted) radiation escaping (into space) OR radiation re-emitted / reflected back to surface (by atmosphere / greenhouse gases) OR (amount of) radiation absorbed is greater than (the amount of) radiation leaving the atmosphere B1 Question Answer Marks 6(a)(i) 0.008(0) A OR 8(.0) mA OR 8(.0)  10–3 A A3 (p.d. across 400  resistor =) 5 – 1.8 OR 3.2 (V) C1 (I =) V / R OR 3.2 / 400 C1 6(a)(ii) increases B1 resistance of LDR increases B1 ratio of potential differences (across each component) equals ratio of the two resistances OR R1 / R2 = V1 / V2 OR LDR has greater share of the total / supply voltage OR potential difference of the source is divided between the resistor (R) and LDR B1 6(b)(i) 56 mA OR 5.6  10–2 A A2 44 (mA) OR 12 (mA) C1 6(b)(ii) 0 (A) B1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 16 of 20 Question Answer Marks 7(a)(i) provide a continuous connection (between the coil and the lamp) OR prevent the contacts reversing every half turn / 180° OR prevent the wires (to the lamp) twisting / tangling B1 7(a)(ii) any three from: • coil is rotated / moved in magnetic field • coil cuts (magnetic) field OR changing (magnetic) field through coil • e.m.f. / voltage induced • coil forms part of a complete circuit (through the lamp) so there is a current • as one side of the coil starts to move in the opposite direction, current is induced in the opposite direction OR direction of current in coil is reversed every half turn / 180° B3 7(a)(iii) any two from: • increase strength of magnetic field • increase speed of rotation (of the coil) • increase number of turns (of coil) B2 7(b)(i) 2.5 (revolutions) B1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 17 of 20 Question Answer Marks 7(b)(ii) any 1 correct = 1 mark any 2 or 3 correct = 2 marks all 4 correct = 3 marks Time Label from graph coil position A B C D B3 N S N S N S N S

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 18 of 20 Question Answer Marks 8(a)(i) most of the atom is empty space OR nucleus is (very) much smaller than the atom B1 8(a)(ii) nucleus must have a positive charge OR (the positive) charge is concentrated at the centre of the atom OR most of the mass (of the atom) is concentrated in the nucleus B1 8(b)(i) P B1 alpha particles have greater mass so are deflected less (than the beta particles) B1 8(b)(ii) upwards AND alpha particles are positively charged so attracted towards negatively charged plate OR direction of field is direction of force on positive charge B1 8(c) 1.9  10–2 g OR 1.9  10–5 kg A2 3 half-lives OR 2.4  10–3  23 OR 1 / 8 C1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 19 of 20 Question Answer Marks 9(a)(i) (shortly after) Big Bang OR when Universe was formed B1 9(a)(ii) Increased B1 Universe has expanded OR Universe accelerated outwards B1 9(b)(i) 120 000 (km / h) OR 1.2  105 (km / h) A3 (v =) 2r / T OR {2    108 ( 106 ) } / {0.62  365  24} C1 (T =) 0.62  365  24 OR (T =) 5431 OR (T =) 226.3  24 OR 1.2  10n C1 9(b)(ii) decreases B1

0625/43 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 20 of 20 Question Answer Marks 10(a) elliptical shape drawn B1 S at a focus of the ellipse by eye B1 10(b) L furthest away from their S / Sun B1 10(c) total energy = gravitational (potential) energy + kinetic energy B1 (energy stored as) GPE decreases and (energy stored as) KE increases closer to the Sun B1 when the comet has more kinetic energy it has a greater speed B1 S OR S S L