Light — Paper 4 · IGCSE Sciences - Co-ordinated (Double) 0654

13 A student is climbing a mountain. (a) During a storm, she sees lightning strike a tree in the distance. Several seconds later she hears the sound of the thunder caused by the lightning. (i) Explain why she sees the lightning several seconds before she hears the thunder. … … [1] (ii) The base of the thunder cloud is negatively charged. Fig. 13.1 shows the cloud above the ground. thunder cloud – – – – – – – – – – – + + + + + + + + + + + + + + ground Fig. 13.1 In the space between the negative charge on the cloud and the positive charge on the ground, there is an electric field. State what is meant by the term electric field. … … [1] (iii) A lightning flash occurs when the thunder cloud loses some of its charge to the ground. One lightning flash discharges 1.21 C in 0.00 011 s. Calculate the average current that passes between the thunder cloud and the ground. State the formula you use and show your working. formula working current = … A [2] (b) The student uses a camera to take photographs when she reaches the top of the mountain. The camera uses a converging lens. Fig. 13.2 shows an incomplete ray diagram for a converging lens forming an image. object F F Fig. 13.2 (i) On Fig. 13.2, complete the ray diagram to show the three rays of light after they have passed through the lens. One ray has been drawn for you. [1] (ii) On Fig. 13.2, draw an arrow ↓ to show where the image is formed. [1]

6 marks

Mark scheme: 13(a)(i) light travels faster than sound ; 1 13(a)(ii) region where a charge experiences a force ; 1 13(a)(iii) current = charge / time / 1.21 / 0.00011 ; = 11000 (A) ; 2 13(b)(i) middle ray passes through without deviation AND bottom ray passes out parallel to principal axis AND all 3 rays pass through a point ; 1 13(b)(ii) inverted arrow drawn from principal axis to intersection of three rays ; 1

This question in 0654/41 May/June 2017

12 (a) Fig. 12.1 shows two forces acting on a swimmer as he swims in a swimming pool. frictional force driving force 80 N 100 N Fig. 12.1 (i) State the size and direction of the resultant force. size … direction … [2] (ii) State how the speed of the swimmer is changing. Explain your answer. … … … [2] (b) The swimmer starts a race when he hears the starting sound from a loudspeaker. (i) The sound waves travel through the air. Fig. 12.2 represents a sound wave travelling through the air. The sound wave travels by a series of compressions (C) and rarefactions (R). C R C R C R C R C R C Fig. 12.2 Use Fig. 12.2 to describe one difference between a region of compression and a region of rarefaction. … … … [1] (ii) Water waves are transverse waves. Sound waves are longitudinal waves. Describe the difference between a transverse wave and a longitudinal wave. You may draw a labelled diagram if it helps your answer. … … … … [2] (c) There are submerged lamps in the pool. Fig. 12.3 shows two light rays from one of these lamps. X air Y water 60° 20° lamp Fig. 12.3 The critical angle for the boundary between water and air is 48°. On Fig. 12.3, complete the paths of the two rays after they reach the surface at X and Y. Explain your answer. … … … [3]

10 marks

Mark scheme: 12(a)(i) 20 N ; forwards / to the right ; 2 12(a)(ii) the swimmers speed increases/ acceleration ; resultant force/ unbalanced force, to right / in direction of movement, /driving force > frictional force ; 2 12(b)(i) compressions are regions where the particles in air are close together / rarefactions are regions where the particles in air are spread out ; compressions are regions with air at high pressure / rarefactions are regions with air at low pressure ; max 1 12(b)(ii) transverse waves oscillate at right angles to direction of wave/energy transfer ; longitudinal waves oscillate parallel to direction of wave/energy transfer ; 2 12(c) at Y reflection only is shown ; at X refraction (and reflection) is shown ; total internal reflection occurs when angle of incidence exceeds critical angle / angle of incidence = angle of reflection / refraction away from normal when ray travels from denser to less dense medium ; 3

This question in 0654/41 Oct/Nov 2017

9 (a) A boy riding his bicycle is cooled by sweating. Describe, in terms of molecules, how sweating cools his body by evaporation. … … … … … [3] (b) Fig. 9.1 shows a car behind a bicycle at night. Fig. 9.1 A reflector on the back of the bicycle is made from many small red plastic prisms, one of which is shown in Fig. 9.2. A ray of light from the headlamp of the car enters the prism. ray of light from the headlamp of the following car red plastic prism Fig. 9.2 Total internal reflection occurs within the prism. On Fig. 9.2, complete the path taken by the ray of light until it emerges from the prism. [2] (c) The bicycle has a lamp powered by a small generator. The generator turns as the boy pedals and the lamp lights up. Fig. 9.3 shows a simple version of the generator. axle magnet magnet N S slip ring coil brush lamp Fig. 9.3 Describe how the rotating coil causes the lamp to light. … … … … … … [3] (d) The generator produces an alternating voltage. Fig. 9.4 shows how the output voltage of the bicycle generator changes with time. 6.0 4.0 2.0 voltage / V 0 time / s 0.02 0.04 0.06 0.08 0.10 –2.0 –4.0 –6.0 Fig. 9.4 (i) Calculate the frequency of the alternating voltage. Show your working. frequency = … Hz [1] (ii) State the amplitude of the alternating voltage. amplitude = … V [1] (e) A different bicycle has a front lamp, A, and a rear lamp, B, powered by the same battery. Fig. 9.5 shows how the lamps are connected. 12 V A B Fig. 9.5 (i) State the name given to this arrangement of lamps in a circuit. … [1] (ii) Lamp A has a resistance of 5 Ω. The battery has a voltage of 12 V. Calculate the current flowing through lamp A when the switch is closed. State the formula you use and show your working. formula working current = … A [2] (iii) Lamp B has a resistance of 10 Ω. Calculate the combined resistance of the two lamps in this circuit. Show your working. resistance = … Ω [2]

15 marks

Mark scheme: 9(a) fastest moving / most energetic molecules escape ; remainder are slower / have less energy ; energy used taken from surroundings / molecules gain energy from body ; 3 9(b) first 90° reflection correct ; second 90° reflection correct ; 2 9(c) rotation of coil, cuts magnetic field / experiences changing magnetic field ; induces an emf ; current flows through lamp / pd across lamp causes lamp to light ; 3 9(d)(i) frequency = 25 (Hz) ; 1 Question Answer Marks 9(d)(ii) amplitude = 5 (V) ; 1 9(e)(i) parallel ; 1 9(e)(ii) I = V / R or 12 / 5 ; 2.4 (A) ; 2 9(e)(iii) 1 2 1 2 T R R R R R = + or R = 10 / 3 (Ω) ; = 3.3 (Ω) ; 2

This question in 0654/42 Oct/Nov 2017

3 (a) A radioactive isotope of iodine is used by a doctor to examine the thyroid gland of a patient. The patient takes a tablet containing the iodine, which is absorbed by the thyroid gland. The iodine emits γ-rays that are detected outside the body. Iodine-123 has a half-life of 13 hours. Suggest why the half-life of iodine-123 makes it suitable for use in the investigation of the thyroid gland. … … … [2] (b) Endoscopes are used by doctors to observe inside a patient. An endoscope uses optical fibres. (i) Complete Fig. 3.1 to show how a ray of light travels down an optical fibre by total internal reflection. Fig. 3.1 [1] (ii) Describe how light passes along optical fibres. Use the terms critical angle and total internal reflection in your answer. … … … … … [2]

5 marks

Mark scheme: 3(a) long enough to be detected in the body ; short enough for minimal risk ; 2 3(b)(i) ray of light reflects along the fibre – all angles approx. correct ; 1 3(b)(ii) no refraction / light does not escape through sides / only (total) internal reflection ; angle of incidence is greater than critical angle ; 2

This question in 0654/43 Oct/Nov 2017

3 (a) A torch (flashlight) contains four cells connected in series and two lamps X and Y connected in parallel. Each lamp has a separate switch. (i) Draw a circuit diagram for the torch using electrical circuit symbols. [3] (ii) The current passing through lamp X is 0.5 A. The resistance of lamp X is 12 Ω. Calculate the total potential difference supplied by the four cells. State the formula you use and show your working. formula working potential difference = … V [2] (iii) Calculate the charge passing through lamp X in two minutes. State the formula you use and show your working. formula working charge = … C [2] (b) Fig. 3.1 shows a torch shining at a plane mirror. Fig. 3.1 A ray of light reflects off the mirror. (i) Complete Fig. 3.1 to show the ray of light reflecting off the mirror. [2] (ii) On Fig. 3.1, mark and label the angle of incidence with the letter i. [1] (iii) The angle of incidence is 45°. State the angle of reflection. Explain your answer. angle of reflection … ° explanation … … [1]

11 marks

Mark scheme: 3(a)(i) two lamps in parallel ; each switch operates one lamp only ; all symbols and everything else correct ; 3 3(a)(ii) voltage = current × resistance or 0.5 × 12 ; = 6 (V) ; 2 3(a)(iii) charge = current × time or 0.5 × 120 ; = 60 (C) ; 2 3(b)(i) ray reflects ; at approximately correct angle ; 2 3(b)(ii) angle i correctly labelled ; 1 3(b)(iii) 45° AND angle of incidence = angle of reflection ; 1

This question in 0654/41 Oct/Nov 2018

6 (a) A fire engine communicates with the fire station using radio waves. The fire engine uses a blue flashing light and a siren to warn people. (i) Radio waves and visible light are both parts of the electromagnetic spectrum. Fig. 6.1 shows an incomplete electromagnetic spectrum. On Fig. 6.1 place radio waves and visible light in their correct places. X-rays microwaves Fig. 6.1 [1] (ii) Blue light waves have a frequency of 665 THz (1 THz = 1012 Hz). Blue light waves have a wavelength of 450 nm (1 nm = 10−9 m). Calculate the speed of blue light waves in m / s. State the formula you use and show your working. Give your answer to 3 significant figures. formula working speed = … m / s [2] (b) A motorcyclist hears the siren from the fire engine. The motorcyclist looks in his rear-view mirror to see the fire engine. Fig. 6.2 shows the path of a ray of light from the fire engine to the eye of the motorcyclist. fire engine motorcyclist’s eye Fig. 6.2 (i) On Fig. 6.2, draw the rear-view mirror in its correct position. [2] (ii) On Fig. 6.2, mark and label the angle of incidence with the letter i. [1] (iii) The angle of incidence is 30°. State the angle of reflection. Explain your answer. angle of reflection = … ° explanation … … [1]

7 marks

Mark scheme: 6(a)(i) radio on right hand side and visible in the middle ; 1 6(a)(ii) speed = frequency × wavelength or 665 × 1012 × 450 × 10–9 / 299 250 000 (m/s) ; 299 000 000 (m / s) ; 2 6(b)(i) mirror drawn at point of reflection ; correct angle at point of reflection ; 2 6(b)(ii) angle i correctly labelled ; 1 6(b)(iii) 30° AND angle of incidence = angle of reflection ; 1

This question in 0654/42 Oct/Nov 2018

12 (a) The body of a car is usually made from steel. The bodies of some cars are made from aluminium. Suggest a simple way of deciding whether the body of a car is made from either steel or aluminium. Explain your answer. … … … [1] (b) In a car, relays are often used as switches in electrical circuits that use large currents. Explain why relays are used in this way. … … … [1] (c) A car driver uses mirrors to see behind the car. Fig. 12.1 shows a ray of light striking a mirror. mirror Fig. 12.1 (i) On Fig. 12.1, draw the normal at the point where the ray strikes the mirror and label with the word normal. [1] (ii) On Fig. 12.1, draw the reflected ray and label with the words reflected ray. [1] (iii) On Fig. 12.1, mark the angle of reflection and label with the letter r. [1] (d) Fig. 12.2 shows a black car and a white car. Fig. 12.2 The cars are parked next to each other on a sunny day. Suggest why the black car gets hotter than the white car. … … [1] (e) The black car accelerates up a hill. Apart from thermal energy, state two forms of energy gained by the car as it accelerates up the hill. 1 … energy 2 … energy [2] (f) During a journey, the black car travels 1500 m along a straight road in 90 s. The driving force of the car’s engine is 14 000 N. (i) Calculate the work done by the driving force. State the formula you use and show your working. formula working work done = … J [2] (ii) Calculate the useful power output from the car’s engine during this period. State the formula you use, show your working and state the unit of your answer. formula working power = … unit … [3]

13 marks

Mark scheme: 12(a) use a magnet (no mark) steel is magnetic / attracted to a magnet ; 1 12(b) to switch high current circuits using a small current circuit / so a high current circuit can be switched safely / so that a switch with a low current rating can be used to switch a high current ; 1 12(c)(i) normal drawn and labelled ; 1 12(c)(ii) reflected ray drawn with approx. correct angle of reflection ; 1 12(c)(iii) correctly labelled angle of reflection ; 1 12(d) black surfaces are better absorbers of thermal radiation (than white surfaces) / white surfaces are better reflectors of thermal radiation (than black surfaces) ; 1 12(e) kinetic ; gravitational (potential) ; 2 12(f)(i) work = force × distance or 14 000 × 1500 ; = 21 000 000 (J) ; 2 12(f)(ii) power = energy time or work time or 21000000 90 ; = 230 000 ; W ; 3

This question in 0654/43 Oct/Nov 2018

12 Fig. 12.1 shows a solar-powered golf cart, with solar cells on the roof. Fig. 12.1 The solar cells produce electrical energy using solar energy. The Sun is the source of this energy. (a) Name two energy resources that do not have the Sun as their source of energy. 1 … 2 … [1] (b) During the golf cart’s journey, the temperature in the tyres increases. The volume of air in the tyres does not change. Explain in terms of molecules the effect on the pressure of a gas due to an increase in temperature at constant volume. … … … … [2] (c) The golf cart often travels across sloping fields so stability is important in its design. Fig. 12.2 shows the cart on a slope. X Fig. 12.2 The centre of mass of the golf cart is shown by the letter X. State the effect of raising the centre of mass of the golf cart on its stability. … … [1] (d) A spectator takes a photograph of a golfer with a camera. The camera uses a thin converging lens to focus light rays onto the light sensor inside the camera. (i) Complete the ray diagram in Fig. 12.3 to show this. camera lens light rays light from golfer sensor Fig. 12.3 [1] (ii) The lens is made from glass. Glass has a refractive index of 1.33. Define refractive index in terms of the speed of light in a vacuum and in glass. … … [1] (iii) The image produced by the lens on the light sensor is a real image. Describe the difference between a real image and a virtual image. … … [1] (e) Describe in terms of the forces between the atoms why solids have a fixed shape. … … [1] [Total: 8]

8 marks

Mark scheme: 12(a) any two from geothermal nuclear tidal ; 1 12(b) increase in pressure because molecules are moving faster / have more KE ; collide with walls of tyre more frequently / at greater speed / with greater force ; 2 12(c) less stable ; 1 12(d)(i) two straight rays brought to a focus on the light sensor ; 1 12(d)(ii) speed of light in vacuum ÷ speed of light in glass ; 1 12(d)(iii) real image can be projected onto a screen / is formed where the light rays converge ; virtual image is one from which the light rays appear to come from that image ; max 1 12(e) (fixed shape because) strong forces (keep particles in regular / fixed arrangement) ; 1

This question in 0654/41 May/June 2019

9 (a) Ultrasound waves are used in hospitals to scan unborn babies. Ultrasound waves have a frequency that is too high for a human to hear. (i) State, in terms of waves, what is meant by the term frequency. … … [1] (ii) Using your knowledge of the range of audible frequencies for a healthy human ear, suggest a frequency for these ultrasound waves. frequency = … Hz [1] (iii) Ultrasound waves are longitudinal waves. Describe what is meant by a longitudinal wave. … … [1] (b) Endoscopes are used by doctors in hospitals to observe the inside of a patient. An endoscope uses optical fibres. Complete Fig. 9.1 to show how a ray of light travels down an optical fibre by total internal reflection. Fig. 9.1 [2] (c) An isotope of strontium, strontium-89, is used in the treatment of bone cancer in hospitals. Strontium-89 has a half-life of 50 days. A sample of this isotope contains 4 × 1014 atoms. Some time later 3 × 1014 atoms have decayed. Calculate the time needed for this number of atoms to decay. Show your working. time = … days [3] [Total: 8]

8 marks

Mark scheme: 9(a)(i) number of waves passing a given point per unit time ; 1 9(a)(ii) frequency greater than 20 000 Hz ; 1 9(a)(iii) vibration / oscillation is in the same direction as energy transfer ; 1 9(b) total internal reflection shown ; angle correct ; 2 9(c) 1 × 1014 (atoms remain) ; indication of 2 half-lives ; (50 × 2 = ) 100 days ; 3

This question in 0654/42 May/June 2019

6 (a) Fig 6.1 shows a penguin walking on the ice in Antarctica. Fig. 6.1 The penguin has a weight of 25 N and its feet have a total area of 22 cm2. Calculate the pressure in N / m2 exerted by the penguin on the ice when it is standing on both feet. Show your working. pressure = … N / m2 [3] (b) The penguin observes a fish swimming in a pool. Fig. 6.2 shows a ray of light going from the fish to the penguin. The ray is refracted at the surface. The angles of incidence and refraction are shown. 42° 30° Fig. 6.2 Calculate the refractive index of water. Show your working. refractive index = … [2] (c) The penguin jumps into the pool of water and produces water waves. A 3-metre section of the pool is shown in Fig. 6.3. 3.0 m Fig. 6.3 (i) Show that the wavelength of the waves is 0.5 m. [1] (ii) The speed of the waves produced in the pool is 1.5 m / s. Calculate the frequency of the waves. Show your working. frequency = … Hz [2] (d) In the Antarctic, harmful ultraviolet radiation reaches the Earth’s surface. (i) State one danger to living things of being exposed to large quantities of ionising radiation. … [1] (ii) α-particles and β-particles are both types of ionising radiation. State two differences between an α-particle and a β-particle. 1 … … 2 … … [2] (iii) An isotope of an unknown element decays by β-emission to produce an isotope of silicon, which has a nucleon number of 28. Identify the unknown element and give its full nuclide notation. A periodic table is shown on page 32. … [2] [Total: 13]

13 marks

Mark scheme: 6(a) conversion of cm2 to m2 seen ; = 11 000 (N/m2) ; 3 6(b) 0.67 / 0.50 ; 1.3 ; 2 6(c)(i) 3.0 / 6.0 ; 1 6(c)(ii) f 1.5 / 0.5 ; = 3 (Hz) ; 2 6(d)(i) cancer / mutation ; 1 6(d)(ii) α particles are larger/heavier ; α particles have positive charge and β particles have negative charge ; α particles are more ionising ; α particles are less penetrating ; max 2 6(d)(iii) l 28A 13 1 mark for Al ; 1 mark for 13 and 28 in correct positions ; 2

This question in 0654/43 May/June 2019

12 (a) Ultrasound is very high frequency sound. A submarine uses ultrasound to determine the distance to the sea bed. Pulses of ultrasound are sent out through the water. The ultrasound pulses reflect off the sea bed and are detected in the submarine 1.2 seconds later. Ultrasound waves travel through water at a speed of 1500 m / s. (i) Calculate the distance of the sea bed below the submarine. distance = … m [2] (ii) The wavelength of ultrasound is 5 cm. Show that the frequency of the ultrasound is 30 000 Hz. [2] (iii) Ultrasound waves travel as a series of compressions and rarefactions. Fig. 12.1 shows the positions of some compressions and rarefactions of an ultrasound wave. Fig. 12.1 On Fig. 12.1 label a compression with the letter C and a rarefaction with the letter R. [1] (b) Submarines use periscopes to view ships on the surface of the sea. Fig. 12.2 shows an incomplete simple periscope. ship periscope observer looking at object Fig. 12.2 On Fig. 12.2, draw: • two plane mirrors in position so that a ray of light from the ship passing through the periscope will be reflected by both mirrors to the observer’s eye • the path of this ray of light from the ship, through the periscope, to the observer’s eye. [3] (c) The submarine has a generator to generate electricity. Fig. 12.3 shows a simple generator. coil N S Z a.c. output Fig. 12.3 (i) Name the parts of the generator labelled Z on Fig. 12.3. … [1] (ii) Explain why a rotating-coil generator produces an alternating current. … … … … [3] [Total: 12]

12 marks

Mark scheme: 12(a)(i) depth = 1800 / 2 = 900 (m) ; 2 12(a)(ii) 0.05 (m) OR 150 000 (cm / s) ; (f = ) 1500 / 0.05 OR 150 000 / 5 ; ( = 30 000 Hz) 2 12(a)(iii) compression and rarefaction correctly identified ; 1 12(b) two mirrors in correct places ; two plane mirrors in correct places and correct orientations ; correct reflections shown ; 3 12(c)(i) slip rings ; 1 12(c)(ii) coil cuts lines of magnetic field / coil moves in magnetic field / coil experiences changing magnetic field ; e.m.f. / current induced ; each side of coil moves upwards and then downwards (through field as it turns) owtte ; current changes direction every half turn / flows in one direction and then the other ; max 3 3

This question in 0654/41 Oct/Nov 2019

12 A fishing boat floats on the sea. (a) A heavy anchor is dropped from the boat and accelerates as it falls through the water to the sea bed. Name the downward force that makes the anchor accelerate. … [1] (b) The boat has a small generator to generate electricity. Fig. 12.1 shows a simple generator. N S Fig. 12.1 (i) On Fig. 12.1 label a slip ring with the letter R. [1] (ii) Describe how the use of slip rings produces an alternating voltage output from the rotating coil. … … … [2] (iii) On the grid in Fig. 12.2, sketch a graph of voltage output against time for the generator, when the coil is rotating at a constant speed. voltage output time Fig. 12.2 [2] (c) An electric heater on the boat uses the electricity generated at 240 V. The current passing through the heater is 20 A. Calculate the charge passing through the heater in one hour. State the unit of your answer. charge = … unit … [3] (d) A fisherman on the boat is using a pair of binoculars to look at the sea. Binoculars use glass prisms to reflect light. Fig. 12.3 shows part of a pair of binoculars. A ray of light is shown entering and leaving. glass prism light ray entering light ray leaving Fig. 12.3 On Fig. 12.3, complete the ray diagram to show the path of the light ray through the two prisms. [1] [Total: 10]

10 marks

Mark scheme: 12(a) weight ; 1 12(b)(i) slip rings labelled correctly ; 1 12(b)(ii) induced voltage changes every half turn ; same side of coil remains connected to same slip ring ; 2 12(b)(iii) approx. sine curve ; regular frequency and amplitude ; 2 12(c) (charge =) current × time or 20 × 1 × 60 × 60 ; 72 000 ; C ; 3 12(d) ray drawn correctly through first prism and through second prism ; 1

This question in 0654/42 Oct/Nov 2019

12 A gardener cuts grass with an electric mower. damp grass gardener power electric cable mower cut in insulation covered with tape Fig. 12.1 (a) Use the information in Fig. 12.1 to explain why the cut in insulation is an electrical hazard. … … [1] (b) The mower is noisy. Sound waves from the lawn mower pass through the air as a series of compressions and rarefactions. (i) State what is meant by a compression. … … [1] (ii) Describe the wavelength of a sound wave in terms of compressions. … … [1] (iii) Sound waves are longitudinal waves. Describe the differences between longitudinal and transverse waves. You may draw a diagram if it helps your answer. … … … … … [2] (c) The gardener places mirrors in his garden to scare cats away. When a cat sees its image in the mirror it runs away. Describe the image formed in a plane mirror by using three words or phrases from the list. laterally inverted magnified not upside down real same size smaller upside down virtual 1 … 2 … 3 … [2] (d) Fig. 12.2 shows a heater in the garden. The heater burns butane gas. reflecting hood gas flames gas bottle Fig. 12.2 The underside surface of the hood is shiny and light in colour. Suggest why this is a more suitable surface than a dull and dark colour. … … [1] [Total: 8]

8 marks

Mark scheme: 12(a) tape repair may let in water / short circuit / fire / electrocution ; 1 12(b)(i) region of high pressure / region of a high concentration of molecules ; 1 12(b)(ii) distance between two successive compressions ; 1 12(b)(iii) transverse waves – direction of propagation perpendicular to direction of oscillation ; longitudinal – direction of propagation parallel to direction of oscillation ; 2 12(c) Any 3 from laterally inverted ; same size ; virtual ; not upside down ; max 2 2 12(d) shiny / light surface will reflect more thermal energy / dull / dark surface will absorb more thermal energy ; 1

This question in 0654/43 Oct/Nov 2019

9 (a) Visible light and γ-radiation are both used in hospitals. They are both examples of electromagnetic waves. γ-radiation travels at a speed of 3.0 × 108 m / s in a vacuum. (i) State the speed at which visible light travels in a vacuum. speed = … m / s [1] (ii) γ-radiation has a wavelength of 8 × 10–12 m. Calculate the frequency of γ-radiation. State the unit of your answer. frequency = … unit … [3] (b) Doctors use visible light and optical fibres to see inside the human body. Visible light passes along optical fibres by total internal reflection. (i) Fig. 9.1 shows a ray of light passing into an optical fibre. On Fig. 9.1 continue the ray of light to show its path through the optical fibre. light ray optical fibre Fig. 9.1 [1] (ii) Explain why total internal reflection occurs. … … [1] (c) Doctors use an isotope of iodine, I-123, to examine the thyroid gland of a patient. Small quantities of I-123 are absorbed by the thyroid gland. I-123 emits γ-radiation which is detected outside the body. I-123 has a half-life of 13 hours. (i) Give two reasons why I-123 is suitable for use inside the body. 1 … … 2 … … [2] (ii) A sample of I-123 contains 8 × 1014 atoms. Sometime later 6 × 1014 atoms have decayed. Calculate the time needed for this number of atoms to decay. time = … hours [2] [Total: 10]

10 marks

Mark scheme: 9(a)(i) 3 × 108 m/s; 9(a)(ii) v = frequency × wavelength or correct substitution; 3.75 × 1019 ; Hz; 3 9(b)(i) angles approximately correct for at least two reflections; 1 9(b)(ii) angle of incidence exceeds critical angle; 1 9(c)(i) relatively short half-life; γ-radiation can pass through body cells and be detected outside the body; γ-radiation is the least ionising; max 2 9(c)(ii) two half-lives (have occurred); 26 (hours); 2

This question in 0654/41 May/June 2020

3 (a) A car has two identical headlamps L1 and L2. The lamps are connected in parallel across a 12 V battery as shown in Fig. 3.1. L1 L2 Fig. 3.1 (i) The current passing through L1 is 5.0 A. Show that the resistance of L1 is 2.4 Ω. [2] (ii) Calculate the combined resistance of the two lamps connected in parallel. resistance = … Ω [2] (iii) State one reason why the lamps are connected in parallel rather than in series. … … … [1] (b) The headlamps emit visible light. The frequency of some of this light is 6.0 × 1014 Hz. Calculate the wavelength of this light. wavelength = … m [3] (c) The car engine is noisy and emits sound waves that pass through the air as a series of compressions and rarefactions. Fig. 3.2 shows the positions of the compressions and rarefactions as the sound wave passes through the air. Fig. 3.2 (i) On Fig. 3.2 label the centre of a rarefaction with the letter R. [1] (ii) Explain in terms of compressions what is meant by the frequency of a sound wave. … … [1] (d) The steel radiator on the car transfers thermal energy through the radiator wall by conduction. Describe how thermal energy passes through a metal by conduction. … … … … … [2] [Total: 12]

12 marks

Mark scheme: 3(a)(i) R = V ÷ I; = 12 ÷ 5.0; (= 2.4 Ω) 3(a)(ii) 1/RT = 1/R1 + 1/R2 or RT = R1 R2 /R1 + R2 or correct substitution; 1.2 (Ω); 2 3(a)(iii) both lamps get full voltage; if one lamp fails the other will still work; 1 3(b) v = f × λ or correct substitution; (speed of light =) 3 × 108 (m) seen; = 5 × 10–7 (m); 3 3(c)(i) rarefaction correctly labelled with the letter R; 1 3(c)(ii) number of compressions per second; 1 3(d) thermal energy transferred as (vibrational) energy of atoms ; vibrations passed from atom to atom ; delocalised electrons transfer energy ; max 2

This question in 0654/42 May/June 2020

12 (a) A cyclist accelerates along a straight road from a speed of 4 m / s to maximum speed. The combined mass of the cyclist and bicycle is 80 kg. Fig. 12.1 is the speed-time graph for the bicycle and cyclist. 10 9 8 7 speed 6 m / s 5 4 3 2 1 0 0 2 4 6 8 10 12 time / s Fig. 12.1 (i) Use Fig. 12.1 to calculate the acceleration at 2 s. Show your working. acceleration = … m / s2 [2] (ii) Calculate the resultant force acting on the cyclist and bicycle during this acceleration. force = … N [2] (iii) Calculate the maximum kinetic energy of the cyclist and bicycle during the 12 second period in Fig. 12.1. kinetic energy = … J [3] (b) Fig. 12.2 shows a section through a plastic reflector on the bicycle. A ray of light from a car is incident on the flat surface of the reflector. incident ray from car air plastic Fig. 12.2 The incident ray is totally internally reflected. Continue the incident ray on Fig. 12.2 to show the path of the ray of light until it leaves the reflector. [2] (c) Fig. 12.3 shows a metal nut on the bicycle wheel. A B Fig. 12.3 The nut must be turned by either spanner A or spanner B. State why spanner B will turn the nut more easily than spanner A. … [1] [Total: 10]

10 marks

Mark scheme: 12(a)(i) change of speed or correct substitution (e.g. 1.55/2); 0.775 (m/s2); 2 12(a)(ii) F = ma or 80 × 0.775; 62 (N); 2 12(a)(iii) max speed = 9 m/s; KE = ½mv2 or ½ × 80 × 9 × 9; 3240 (J); 3 12(b) reflection only shown at first reflection; after second reflection ray emerges parallel to incident ray; 2 12(c) spanner B is longer / gives a bigger, moment / turning force ; 1

This question in 0654/42 May/June 2020

3 (a) A car travels along a road at 8 m / s. Describe the difference between the terms speed and velocity. … … … [1] (b) Some puddles of water have formed on the road. Explain, in terms of water molecules, how the rate of evaporation of water from a puddle is affected by the strength of the wind blowing across the puddle. … … … … [2] (c) The car battery has an electromotive force (e.m.f.) of 12 V. State what is meant by electromotive force. … … … [2] (d) Fig. 3.1 shows part of the lighting circuit for the car. Two lamps, L1 and L2, each have a resistance of 16 Ω. 12 V fuse L1 L2 Fig. 3.1 (i) When the switch is closed the current in the fuse is 1.5 A. Determine the current in L1. current = … A [1] (ii) State one reason why the lamps are connected as shown in Fig. 3.1 and not in series. Explain your answer. … … … [2] (e) Modern cars use optical fibres to transfer information using visible light rays. Fig. 3.2 shows a ray of light entering an optical fibre. ray of light optical fibre Fig. 3.2 (i) Explain why the ray of light is able to stay inside the optical fibre. You may draw on Fig. 3.2 if it helps your answer. … … … … [2] (ii) Visible light rays are transverse waves. Draw labelled diagrams to show the difference between a transverse wave and a longitudinal wave. [2] [Total: 12]

12 marks

Mark scheme: 3(a) speed has magnitude only / velocity has magnitude and direction / velocity has direction / speed does not have direction ; 1 3(b) increase in wind strength increases rate of evaporation / ORA ; (stronger wind) allows more molecules to escape / evaporate into the air above the puddle / ORA ; 2 3(c) the energy / work done (supplied by a source) ; per (unit) charge ; 2 3(d)(i) 0.75 (A) ; 1 Question Answer Marks 3(d)(ii) if one lamp fails the other will still work ; if one lamp fails still a complete circuit ; OR ref. to full brightness / brighter lamps ; because they each receive the full voltage ; 2 3(e)(i) ref. to total internal reflection / owtte / shown on diagram ; angle of incidence greater than the critical angle ; 2 3(e)(ii) correct diagrams for transverse and longitudinal waves ; vibrations perpendicular to direction of travel for transverse and parallel for longitudinal ; 2

This question in 0654/41 Oct/Nov 2020

12 (a) Fig. 12.1 shows a truck crossing a bridge. Fig. 12.1 The bridge is designed with gaps in the road surface as shown in Fig. 12.2. road surface metal strip gaps Fig. 12.2 The temperature of the road surface increases on a hot day. (i) Describe what happens to the gaps in the road surface when the temperature increases. Explain your answer. … … … [2] (ii) Suggest what may happen to the bridge if there were no gaps in the road surface. … … [1] (b) Fig. 12.3 shows the fuel tank of the truck being filled with diesel fuel. – – – – – – – + + – + + + + + + + + + + ++ + delivery diesel pipe fuel fuel tank Fig. 12.3 Explain why the diesel fuel becomes positively charged. … … … [2] (c) The truck has a warning triangle to alert other drivers. Fig. 12.4 shows the warning triangle. Fig. 12.4 Many tiny prisms are contained in the warning triangle. Fig. 12.5 shows one ray of light entering a prism. Fig. 12.5 The ray undergoes total internal reflection inside the prism. Complete Fig. 12.5 to show the path of the ray of light through the prism and the ray of light leaving the prism. [2] (d) The truck has a generator. Fig. 12.6 shows a simple generator producing an alternating voltage. Fig. 12.6 (i) On Fig. 12.6, label the coil C. [1] (ii) On Fig. 12.6, label the slip rings S. [1] (iii) Describe how turning the coil induces an alternating voltage. … … … … [3] [Total: 12]

12 marks

Mark scheme: 12(a)(i) gap closes ; road expands in the heat ; 2 12(a)(ii) (the road will) buckle / bend / break / be damaged ; 1 Question Answer Marks 12(b) ref to friction / described ; transfer of electrons ; from the fuel (to the pipe) ; max 2 2 12(c) reflection only shown at first reflection ; after second reflection ray emerges parallel to incident ray ; 2 12(d)(i) coil correctly labelled ; 1 12(d)(ii) slip rings correctly labelled ; 1 12(d)(iii) magnetic field ; rotating coil cuts magnetic field or flux / experiences a changing magnetic field ; e.m.f. / current reverses every half turn ; 3

This question in 0654/42 Oct/Nov 2020

3 (a) A flea is a small insect. A student uses a magnifying glass to observe a flea. The magnifying glass produces a virtual image. Describe the difference between a real image and a virtual image. … … [1] (b) (i) The flea jumps upwards from rest. The speed of the flea increases to 1.2 m / s in 0.001 s. State the difference between the terms speed and velocity. … … … [1] (ii) Calculate the acceleration of the flea. acceleration = … m / s 2 [2] (iii) The flea has a mass of 0.0005 g. Calculate the force causing this acceleration. force = … N [3] [Total: 7]

7 marks

Mark scheme: 3(a) a real image is formed where light rays, converge / are focussed ; a virtual image is formed from where light rays appear to have diverged from ; a real image can be formed on a screen ; a virtual image cannot be formed on a screen ; max 1 3(b)(i) speed has magnitude only / velocity has magnitude and direction / velocity has direction / speed does not have direction ; 1 3(b)(ii) change in speed time taken or − v u t or Δv t or 1.2 0.001 ; 1200 (m / s2) ; 2 3(b)(iii) conversion of grams to kilograms; (force =) mass × acceleration or 0.0000005 × 1200 ; = 0.0006 (N); 3

This question in 0654/43 Oct/Nov 2020

9 Visible light is a transverse wave and is part of the electromagnetic spectrum. (a) State what is meant by a transverse wave. … … [1] (b) Fig. 9.1 shows a ray of visible light from a torch (flashlight) shining into a rectangular glass block. glass air Fig. 9.1 (i) Complete Fig. 9.1 to show the path the ray takes through and out of the block. [2] (ii) State the term used to describe what happens to the ray of light as it enters the glass block. … [1] (iii) Explain why this happens to the ray of light. … … [1] (c) Fig. 9.2 shows the electrical circuit used in the torch. Fig. 9.2 When the switch is closed, the current in the lamp is 1.8 A and the potential difference across the lamp is 3.0 V. Calculate the power output of the lamp. power = … W [2] (d) Fig. 9.3 shows two lamps, identical to the torch lamp, connected in parallel. A Fig. 9.3 (i) When the switch is closed, the ammeter reads 2.6 A. State the current in each lamp. current = … A [1] (ii) Calculate the quantity of charge passing through one of the lamps in Fig. 9.3 when it is switched on for 30 seconds. Give the correct unit for your answer. charge = … unit = … [3] [Total: 11]

11 marks

Mark scheme: 9(a) vibrations / oscillations, are perpendicular to direction of energy transfer ; 1 9(b)(i) ray moves towards the normal inside glass block ; ray emerges parallel to incidence ray ; 2 9(b)(ii) refraction ; 1 9(b)(iii) change of speed / caused by change in density of medium ; 1 9(c) (P=) IV / 1.8 × 3.0 ; 5.4 (W) ; 2 9(d)(i) 1.3 (A) ; 1 Question Answer Marks 9(d)(ii) (Q =) It / 1.3 × 30 ; 39 ; C / Coulombs ; 3

This question in 0654/42 Feb/March 2021

3 (a) Fig. 3.1 shows a student observing an exploding firework. Fig. 3.1 The firework produces light and sound at the same time. The student measures the time between seeing the light and hearing the sound. (i) It takes 3.50 seconds for the student to hear the sound. Calculate the distance between the student and the firework. The speed of sound in air is 340 m / s. distance = … m [2] (ii) Suggest an appropriate measuring instrument the student uses to measure the time it takes to hear the sound. … [1] (iii) Explain why this method cannot be used to measure the speed of light. … [1] (b) Fig. 3.2 shows a ray of light being refracted as it passes from air into glass. 42° air glass 29° Fig. 3.2 Calculate the refractive index of the glass block. State the formula you use and show your working. Give your answer to two significant figures. refractive index = … [3] (c) Fig. 3.3 shows an accurate diagram of a ray of light passing into an optical fibre. X Y Fig. 3.3 (i) Explain why the ray does not change direction at point X on Fig. 3.3. … … [1] (ii) State the full name of the type of reflection that occurs at point Y on Fig. 3.3. … [1] (iii) State one use for optical fibres. … [1] [Total: 10]

10 marks

Mark scheme: 3(a)(i) (d=) v × t / 340 × 3.50 ; 1190 (m) ; 2 3(a)(ii) stopwatch ; 1 3(a)(iii) time taken would be too short to measure / speed of light is much greater ; 1 3(b) (n =) sin i / sin r ; sin42 / sin29 or 1.380192509 ; 1.4 ; 3 3(c)(i) angle of incidence is zero / ray perpendicular to boundary / along normal ; 1 3(c)(ii) total internal reflection ; 1 3(c)(iii) communication / medicine ; 1

This question in 0654/42 May/June 2021

3 (a) State the speed of electromagnetic waves in a vacuum. … [1] (b) Fig. 3.1 shows an incomplete electromagnetic spectrum. (i) Write visible light in its correct position in the spectrum. [1] ultraviolet infrared microwaves Fig. 3.1 (ii) State the form of electromagnetic radiation that has the highest frequency. … [1] (c) Visible light is an example of a transverse wave. (i) Use a double headed arrow (↔ or ↕) to label the wavelength of the transverse wave shown in Fig. 3.2. [1] Fig. 3.2 (ii) State the equation that links the frequency, speed and wavelength of a wave. … [1] (d) Fig. 3.3 shows an object placed close to a thin converging lens. object F F F = principal focus Fig. 3.3 (i) Complete Fig. 3.3 to show how the rays of light from the object form an image. [3] (ii) The image formed by this lens is real. State what is meant by a real image. … … [1] (iii) Suggest a use for a thin converging lens such as the one shown in Fig. 3.3. … … [1] [Total: 10]

10 marks

Mark scheme: 3(a) 3 × 108 m / s ; 1 3(b)(i) ‘visible light’ placed in central box ; 1 3(b)(ii) gamma ; 1 3(c)(i) line drawn peak to peak / trough to trough / any identical points on adjacent waves ; 1 3(c)(ii) v = f λ ; 1 3(d)(i) any two from: ray parallel to the principal axis passing through F on image side ; ray passing through F on object side made parallel to the principal axis ; ray passing through optical centre of lens not refracted ; and image of correct size and position ; 3 3(d)(ii) can be formed on a screen / is formed from real rays of light / formed from converging rays ; 1 3(d)(iii) magnifying glass ; AVP ; max1

This question in 0654/41 Oct/Nov 2021

12 (a) (i) State the speed of visible light in a vacuum. … m/s [1] (ii) Red light has a wavelength of 7.1 × 10–7 m. Use your answer to (a)(i) to calculate the frequency of red light. frequency = … Hz [2] (b) A laser is a device which emits a ray of light. Fig. 12.1 shows a beam of red light from a laser passing through a rectangular glass block. Fig. 12.1 (i) Name the process shown in Fig. 12.1. … [1] (ii) Describe what causes the process shown in Fig. 12.1. … … [2] (c) The laser used in Fig. 12.1 has a useful power output of 1200 W and is 80% efficient. Calculate the power input of the laser. power input = … W [2] [Total: 8]

8 marks

Mark scheme: 12(a)(i) 3 × 108 (m / s) ; 1 12(a)(ii) (f =) v / λ or 3 × 108 / 7.1 × 10–7 ; 4.23 × 1014 (Hz) ; 2 12(b)(i) refraction ; 1 12(b)(ii) change of speed (of the light) ; at the boundary (between materials / different densities) ; 2 12(c) (useful output ÷ eff) × 100 or (1200÷80) × 100 or 1200 ÷ 0.8 ; 1500 (W) ; 2

This question in 0654/42 Oct/Nov 2021

12 (a) Fig. 12.1 shows an incomplete electromagnetic spectrum. radio visible P Q R X-rays γ-rays waves light Fig. 12.1 State the names of the forms of radiation labelled P, Q and R. P … Q … R … [2] (b) Visible light can be used to demonstrate refraction. Fig. 12.2 shows refraction of visible light through a glass block. 30° 15° 15° 30° Fig. 12.2 Calculate the refractive index of the glass block. refractive index = … [2] (c) γ-rays are a form of ionising radiation emitted during radioactive decay. (i) Draw lines to match each form of ionising radiation with its nature and relative ionising effect. One line has been drawn as an example. form of relative ionising nature ionising radiation effect electromagnetic α-particle high radiation β-particle electron medium γ-ray helium nucleus low [2] (ii) Lead-210 ( 21082 Pb) will decay to form an isotope of bismuth. Use the correct nuclide notation to complete the decay equation for lead-210. 210 Pb … Bi + … … 82 83 … [2] (iii) Fig. 12.3 shows the activity of a sample of lead-210. 400 300 activity 200counts / min 100 0 0 20 40 60 80 100 time / years Fig. 12.3 Use Fig. 12.3 to determine the half-life of lead-210. half-life = … years [2] [Total: 10]

10 marks

Mark scheme: 12(a) microwaves infrared ultraviolet ;; 2 12(b) (n =) sin i / sin r or sin 30 / sin 15 ; (n =) 1.93 ; 2 12(c)(i) ;; 2 Question Answer Marks 12(c)(ii) ;; 2 12(c)(iii) identification of 190 counts per min / correct working on graph ; 22 (years) ; 2

This question in 0654/42 Feb/March 2022

9 A student investigates the motion of pollen grains in water seen through a microscope. The student observes that the pollen grains constantly move short distances in random directions. (a) Fig. 9.1 shows the pollen grains suspended in water. Fig. 9.1 (i) State the name given to the motion of these pollen grains. … [1] (ii) Explain why the pollen grains constantly move short distances in random directions. … … … … [2] (b) The microscope uses a thin converging lens to produce an image. Fig. 9.2 shows a thin converging lens. object F F F = principal focus Fig. 9.2 (i) Draw a ray diagram on Fig. 9.2 to show the formation of a real image. Label the image with the word image. [3] (ii) The image formed is a real image. Describe one difference between a real image and a virtual image. … … [1] (c) The visible light that passes through the lens is part of the electromagnetic spectrum. (i) State the speed of visible light in a vacuum. … [1] (ii) γ‑rays and radio waves are also part of the electromagnetic spectrum. Place ticks (✓) in the boxes in Table 9.1 to show which statements are true for γ‑rays and radio waves. Table 9.1 γ‑rays radio waves is used in communication is used in medicine can cause cancer is higher frequency than visible light has a longer wavelength than visible light [3] [Total: 11]

11 marks

Mark scheme: 9(a)(i) Brownian (motion) ; 1 9(a)(ii) ref to collisions (of pollen grains) ; with, light fast-moving particles / water particles or molecules ; 2 9(b)(i) ;; image labelled ; 3 9(b)(ii) real image can be projected on to a screen / is formed when rays of light actually meet / ORA ; 1 F = principal focus Question Answer Marks 9(c)(i) 3  108 m / s ; 1 9(c)(ii) ;;; 3

This question in 0654/42 May/June 2022

2 Fig. 2.1 shows a person removing a damaged branch from a tree. Fig. 2.1 (a) The damaged branch has a mass of 225 kg and is lowered 5.2 m to the ground. Calculate the change in gravitational potential energy (GPE) of the branch as it is lowered to the ground. The gravitational field strength, g = 10 N / kg. change in GPE = … J [2] (b) The damage to the tree was caused by a lightning strike during a thunderstorm. (i) A scientist estimates that the lightning strike transferred 6000 C of charge in 0.20 s. Calculate the average current in the lightning strike. current = … A [2] (ii) The thunderstorm produces both light and sound waves. Explain why an observer sees the light before they hear the sound. … … … … [2] (c) Lightning is caused by electrostatic charges in clouds. Fig. 2.2 shows how charge can form an electric field inside the cloud. positive charge + + + + + + + + electric field _ _ _ _ _ _ _ _ negative charge Fig. 2.2 (i) Fig. 2.2 shows negative charge at the base of the cloud. State the name of the particles that provide this negative charge. … [1] (ii) Describe what is meant by an electric field. … … [1] (d) Thunderstorms can produce gamma radiation and X‑rays as well as visible light. Use the phrases to complete the sentences. You may use each phrase once, more than once or not at all. less than more than the same as The speed of visible light is … the speed of X‑rays. The wavelength of gamma radiation is … the wavelength of visible light. The frequency of X‑rays is … the frequency of gamma radiation. [2] (e) When lightning passes through the air, it heats the air up to 10 000 °C. State and explain what happens to the volume of the air when the temperature increases. Use ideas about molecules in your answer. … … … … [2] [Total: 12]

12 marks

Mark scheme: 2(a) evidence of (GPE =) mgh (in any form) or 225  10  5.2 ; 2 (GPE =) 11 700 (J) ; 2(b)(i) evidence of (I =) Q / t (in any form) or 6000 / 0.20 ; 2 (I =) 30 000 (A) ; 2(b)(ii) light travels faster than sound ; 2 both waves travel the same distance / over a large distance the difference in time is noticeable ; 2(c)(i) electrons ; 1 2(c)(ii) a region in which charged particles experience a force ; 1 2(d) the same as ; 2 less than AND less than ; 2(e) (volume) increases / expands ; 2 molecules, have more (kinetic) energy / move faster or molecules move further apart ;

This question in 0654/42 Feb/March 2023

9 (a) Fig. 9.1 shows a simple circuit containing a heater and a thermistor. heater thermistor Fig. 9.1 Use Fig. 9.1 to explain how increasing the temperature of the thermistor changes the power output of the heater. … … … … … … [3] (b) Fig. 9.2 shows an electric kettle. Fig. 9.2 The kettle has a power rating of 3000 W. It takes 336 kJ of energy to heat some water from room temperature to 100 °C. Calculate the time it will take for the kettle to heat the water from room temperature to 100 °C. time = … s [3] (c) Hot water is poured into two similar cups with lids. One cup is black and the other is white. The temperature of the water in each cup is measured every minute for 15 minutes. Fig. 9.3 shows the results. 80.0 70.0 60.0 50.0 temperature / °C 40.0 30.0 A B 20.0 10.0 0 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 time / minutes Fig. 9.3 State and explain which colour cup gives the results labelled A. A shows the results for the … cup. explanation … … … … [2] (d) Some water is spilt on a table and forms a droplet which acts like a convex lens. Convex lenses can form real and virtual images. Describe the difference between a real image and a virtual image. … … … [1] [Total: 9]

9 marks

Mark scheme: 9(a) resistance of thermistor decreases; 3 current / potential difference, of the heater increases ; power output increases ; 9(b) evidence of unit conversion or 336 000 (J) 3 evidence of (t =) E / P (in any form) or 336 000 / 3000 ; (t =) 112 (s) ; 9(c) white (cup) and 2 white emits less, (IR) radiation / thermal energy, than black ; white / A, cools down more slowly (in 15 minutes) ; 9(d) a real image can be formed on a screen / is formed from real rays of light / is formed from converging rays / AVP ; 1

This question in 0654/42 Feb/March 2023

9 (a) Fig. 9.1 shows a butterfly resting on a leaf attached to the branch of a tree. X pivot point F 5.0 cm Fig. 9.1 (i) State the name of the force labelled F. … [1] (ii) The leaf will break off the branch if the moment about the pivot point X is greater than 0.14 N cm. The leaf does not break off the branch when the butterfly rests on it. Calculate the maximum mass of the butterfly. The gravitational field strength, g, is 10 N / kg. maximum mass = … kg [3] (b) A scientist captures the butterfly in a plastic container to study it more closely. The scientist places a converging lens across the top of the plastic container. Fig. 9.2 shows the butterfly in the container. converging lens Fig. 9.2 Complete Fig. 9.3 to show how a thin converging lens forms a real image. Label the image with the word image. F F = principal focus object Fig. 9.3 [3] (c) The scientist uses a filament lamp to illuminate the butterfly while she is studying it. (i) The filament lamp is in a series circuit with a cell and a switch. Complete Fig. 9.4 to show this circuit. Fig. 9.4 [2] (ii) Fig. 9.5 shows the current–voltage characteristic of a filament lamp. current voltage Fig. 9.5 Use Fig. 9.5 to explain how the resistance of the filament lamp changes as the voltage across it is increased. … … … … … … [3] [Total: 12]

12 marks

Mark scheme: 9(a)(i) weight ; 1 9(a)(ii) (weight =) moment / distance / 0.14 / 5.0 ; (weight =) 0.028 (N) ; (mass = W/g = 0.028 / 10 =) 0.0028 (kg) ; 3 9(b) first ray drawn ; second ray drawn ; image drawn and labelled ; 3 9(c)(i) correct symbols ; in series and all else correct ; 2 9(c)(ii) any three from: (as voltage increases) current increases ; (initially) straight line / gradient is constant, so resistance is constant ; (then) line curves / gradient reduces, so resistance increases ; (resistance increases because) the temperature (of the filament) increases ; 3

This question in 0654/43 May/June 2023

12 Fig. 12.1 shows a ray of light refracted as it enters a glass block. glass block 31° 53° Fig. 12.1 (a) Use Fig. 12.1 to calculate the refractive index of the glass block. Give your answer to 3 significant figures. refractive index = … [2] (b) Fig. 12.2 shows how the refractive index of glass varies with the wavelength of light used. 1.58 1.57 1.56 refractive index 1.55 1.54 1.53 1.52 4.0 5.0 6.0 7.0 violet red wavelength of light / × 10–7 m Fig. 12.2 (i) Use Fig. 12.2 to determine the wavelength of light used in Fig. 12.1. wavelength = … m [1] (ii) Violet light has a wavelength of 4.0 × 10–7 m. Red light has a wavelength of 7.0 × 10–7 m. Describe how Fig. 12.2 shows that red light travels faster through glass than violet light. … … … [1] (c) Fig. 12.3 shows the dimensions of the glass block. 2.0 cm 6.0 cm 12.0 cm Fig. 12.3 The density of glass is 2.80 g / cm3. Use Fig. 12.3 to calculate the mass of the glass block. mass = … g [3] [Total: 7]

7 marks

Mark scheme: 12(a) (n =) sin i / sin r or sin 53° / sin 31° ; 2 (n =) 1.55 ; 12(b)(i) (wavelength =) 4.8  10–7 (m) ; 1 12(b)(ii) refractive index is inversely proportional to speed ; 1 12(c) (volume =) 144 (cm3) ; 3 (mass =) 2.8(0)  144 ; (mass = ) 403 (g) ;

This question in 0654/41 Oct/Nov 2023

6 Light is a transverse wave which is refracted by a transparent material. (a) Fig. 6.1 shows the refraction of a ray of light as it enters a transparent block. transparent block NOT TO SCALE 45° Fig. 6.1 (i) The refractive index of the transparent block is 1.55. The angle of incidence is 45°. Calculate the angle of refraction. angle of refraction = … ° [2] (ii) Information can be transmitted using the total internal reflection of light in an optical fibre. Fig. 6.2 shows a ray of light entering an optical fibre. Fig. 6.2 On Fig. 6.2 complete the ray diagram to show how an optical fibre can transmit light along the fibre. [2] (iii) State what is meant by the term critical angle. … … [1] (b) Lasers are used to produce light of one single wavelength. A battery powered laser has a power output of 0.0060 W and an efficiency of 40%. (i) Calculate the power input provided by the laser’s batteries. power input = … W [2] (ii) A battery of three 1.5 V cells in a laser provides 20.0 C of charge before the cells need replacing. Calculate how long this battery will power the laser for. time = … s [3] [Total: 10]

10 marks

Mark scheme: 6(a)(i) sin45 2 sin r = ; 1.55 (r =) 27(°) ; 6(a)(ii) 2 only TIR ; correct angles ; 6(a)(iii) minimum angle of incidence for TIR to occur ; 1 6(b)(i) 0.0060 power output 2 (efficiency =)  100 or (efficiency =)  100 ; 40 power input (power input =) 0.015 (W) ; 6(b)(ii) (I =) P / V or 0.015 / 4.5 or 0.00333 (A) ; 3 (t = Q / I =) 20.0 / 0.00333 ; (t =) 6000 (s) ;

This question in 0654/42 Oct/Nov 2023

6 Fig. 6.1 shows a jellyfish. Fig. 6.1 (a) The jellyfish experiences an upwards force of 2.1 N from the water. The mass of the jellyfish is 0.15 kg. There are no horizontal forces acting on the jellyfish. Describe and explain the motion of the jellyfish. The gravitational field strength g = 10 N / kg. … … … … [3] (b) Fig. 6.2 shows a scuba diver using a camera to photograph the jellyfish. camera Fig. 6.2 (i) The pressure of the water on the lens of the camera is 180 kPa. The circular lens has a radius of 0.035 m. Calculate the force exerted by the water on the lens of the camera. force = … N [3] (ii) The camera uses a thin converging lens to form an image. Complete Fig. 6.3 to show how a thin converging lens forms an image. Draw two rays to locate the image and draw an arrow to represent the image. object F F F = principal focus Fig. 6.3 [3] [Total: 9]

9 marks

Mark scheme: 6(a) weight = 1.5(N) OR resultant force = 0.6(N) ; upwards resultant force / 0.6 N upwards force ; accelerates upwards ; 3 6(b)(i) area =   0.0352 / 3.848  10–3 ; force = P  A / 180000  area / 180000  3.848  10–3; = 690 (N) ; 3 Question Answer Marks 6(b)(ii) one correct ray drawn ; second correct ray drawn ; image correctly drawn ; 3

This question in 0654/43 May/June 2024

6 Fig. 6.1 shows a mobile phone (cell phone) on a wireless charging pad. mobile phone screen wireless charging pad mains cable Fig. 6.1 (a) The screen of the mobile phone is made from glass. When light travels from air into glass it is refracted and changes direction. (i) Place one tick (3) in each row of Table 6.1 to state the effect on the properties of frequency, speed and wavelength for light as the light travels from air into glass. Table 6.1 decreases stays the same increases frequency speed wavelength [3] (ii) A ray of light is incident on the screen of the mobile phone. The angle of incidence is 53°. The refractive index of glass is 1.5. Calculate the angle of refraction r. r = … ° [2] (b) The mobile phone battery holds a maximum charge of 3300 C. The current used to charge the battery is 0.60 A. Calculate the time taken to fully charge the mobile phone battery. time taken = … s [2] (c) The wireless charging pad in Fig. 6.1 contains a coil of wire. The mains cable provides an alternating current (a.c.) to the coil of wire. The mobile phone contains a second coil of wire. Describe how an electromotive force (e.m.f.) is induced in the second coil of wire when the mobile phone is placed on the charging pad. … … … … [2] [Total: 9]

9 marks

Mark scheme: 6(a)(i) (frequency) stays the same ; 3 (speed) decreases ; (wavelength) decreases ; 6(a)(ii) sin i sin i sin 53 2 evidence of n = or 1.5 = or 1.5 = ; sin r sin r sin r 32(°) ; 6(b) evidence of Q = It or 3300 ÷ 0.60 ; 2 5500 (s) ; 6(c) (idea that) there is a (changing) magnetic field around the coil of wire (in the charging pad) ; 2 the second coil experiences a changing magnetic field (which induces the e.m.f.) ;

This question in 0654/41 Oct/Nov 2024

9 (a) Fig. 9.1 shows distance–time graphs for a car journey and a bicycle journey. bicycle 350 300 250 car distance / m 200 150 100 50 0 0 10 20 30 40 50 60 70 80 time / s Fig. 9.1 The car and bicycle both start from the same point and travel in the same direction along the same road. (i) Use Fig. 9.1 to describe the car journey. … … … [2] (ii) State the time at which the bicycle passes the car. time = … s [1] (iii) The bicycle and rider have a combined mass of 80 kg. Use Fig. 9.1 to calculate the kinetic energy of the bicycle during this journey. kinetic energy = … J [3] (b) Bicycles are fitted with reflectors which reflect light from car headlights. Fig. 9.2 shows a diagram of a reflector. X Y incident light reflected light air air transparent plastic reflector Fig. 9.2 Explain why refraction does not occur: (i) at point X. … … [1] (ii) at point Y. … … … [2] [Total: 9]

9 marks

Mark scheme: 9(a)(i) constant speed, for 20 s / 250 m ; 2 stopping / stationary after 20 s / 250 m ; 9(a)(ii) 50 (s) ; 1 9(a)(iii) (v =) 300 ÷ 60 or 5.0 (m / s) ; 3 (KE =) ½ mv2 or 0.5  80  5.02 ; (KE =) 1000 (J) ; 9(b)(i) (at X) the incident ray is at 90° / right angle to the surface / the angle of incidence is 0° / the incident ray is along the normal ; 1 9(b)(ii) (at Y) total internal reflection occurs ; 2 (because) angle of incidence is greater than the critical angle (for the two media) ;

This question in 0654/43 Oct/Nov 2024

12 (a) Fig. 12.1 shows a 10 Ω resistor and a resistor R of unknown resistance connected in parallel with a 1.8 V cell. R 10 Ω Fig. 12.1 The current in the cell is 0.32 A. The current in the 10 Ω resistor is 0.18 A. (i) Calculate the current in resistor R. current = … A [1] (ii) State the potential difference across resistor R. potential difference = … V [1] (b) A 40 Ω resistor and a 20 Ω resistor are connected in parallel. Calculate the combined resistance of the two resistors. resistance = … Ω [2] (c) (i) A computer projector has a power rating of 750 W. Mains potential difference is 230 V. Calculate the electric current in the projector. current = … A [2] (ii) The computer projector uses a lens to form an image. In another device, the object is placed between the principal focus and the lens. On Fig. 12.2, draw rays to find the position of the image formed. Use an arrow to represent the image. object F F lens Fig. 12.2 [3] (iii) State a use of the arrangement shown in Fig. 12.2. … [1] [Total: 10]

10 marks

Mark scheme: 12(a)(i) (0.32 – 0.18 = ) 0.14 (A) ; 1 12(a)(ii) 1.8 (V) ; 1 12(b) evidence of R = 40  20 / (40 +20) or 1 / R = 1 / 40 + 1 / 20 ; 2 13 () ; 12(c)(i) I = P / V (in any form) or 750 / 230 ; 2 3.3 (A) ; 12(c)(ii) 3 ;;; 12(c)(iii) magnifying glass ; 1

This question in 0654/41 May/June 2025

11 (a) Fig. 11.1 shows a diagram of a water wave. On Fig. 11.1, mark the amplitude and the wavelength of the wave using double-headed arrows (↔ or ↕). Label the amplitude A and the wavelength W. surface of water Fig. 11.1 [2] (b) A water wave has a wavelength of 0.078 m. The frequency of the wave is 0.50 Hz. Calculate the wave speed. wave speed = … m / s [2] (c) (i) Lenses refract light. Complete the ray diagram for the lens in Fig. 11.2 to show the location of the image formed. Draw the image formed with an arrow. converging lens object F F F = principal focus Fig. 11.2 [3] (ii) In another experiment, an object is placed at a distance of less than the focal length from a thin converging lens. Describe the characteristics of the image formed. … … [2] (d) The Sun transfers energy via infrared waves to the Earth. The Earth emits infrared radiation into space. State and explain what happens to the temperature of the Earth during the daytime and during the nighttime. daytime … … nighttime … … [3] [Total: 12]

12 marks

Mark scheme: 11(a) wavelength correct; 2 amplitude correct; 11(b) evidence of v = f or v = 0.5  0.078; 2 0.039 (m/s); 11(c)(i) any 2 from 3 ray parallel to principal axis and refracted through focal point; straight ray from top of object through centre of lens; ray through principal focus and refracted parallel of the principal axis; AND inverted image with arrow in correct location; 11(c)(ii) any two from: 2 upright; magnified; virtual; 11(d) rises in daytime and falls in nighttime; 3 day: energy in (to Earth)  energy out (from Earth); night: energy in (to Earth) > energy out (from Earth);

This question in 0654/43 May/June 2025

12 (a) (i) Seismic P-waves are longitudinal waves. Describe a longitudinal wave. … … [2] (ii) P-waves travel at 6200 m / s in rock. The frequency of a P-wave is 12 Hz. Calculate the wavelength of the P-wave. wavelength = … m [2] (b) Waves spread out when they pass through a narrow gap. (i) State the name of this effect. … [1] (ii) Explain whether sound waves with wavelength of 1.2 m will spread out when passing through a 1.0 m wide doorway. … … [1] (iii) The wavelength of red light is 700 nm. Explain why red light travels in a straight line through the doorway in (b)(ii). … … [1] (c) Light waves travelling in air refract when incident on a boundary with a transparent material. A light ray incident on the boundary at an angle of 57° is refracted at an angle of 44°, as shown in Fig. 12.1. transparent material normal 57° 44° Fig. 12.1 (i) Define refractive index. … … [1] (ii) Calculate the refractive index of the transparent material. refractive index = … [2] [Total: 10]

10 marks

Mark scheme: 12(a)(i) vibrations / oscillations are parallel ; 2 (vibrations / oscillations are parallel) to the direction of propagation / to the direction of travel / to the direction of energy transfer ; 12(a)(ii) evidence of v = f or 6200 = 12 ; 2 520 (m) ; 12(b)(i) diffraction ; 1 12(b)(ii) yes (sound waves spread out) 1 AND wavelength is similar to width of gap ; 12(b)(iii) wavelength is much less than width of gap / ORA ; 1 12(c)(i) ratio of the speeds of a wave in two different regions ; 1 12(c)(ii) n = sin 57 ÷ sin 44 ; 2 1.2 ;

This question in 0654/41 Oct/Nov 2025