Electrical quantities — Paper 4 · IGCSE Science - Combined 0653

9 Fig 9.1 shows a simple test circuit for testing different materials to see how well they conduct electricity. The material being tested is connected between X and Y. A R X Y Fig. 9.1 (a) Name two materials other than copper that would be found to be good conductors when tested. … and … [1] (b) A piece of copper wire is connected between X and Y, and a voltmeter is connected in parallel to resistor R. The ammeter reads 0.5 A. The voltmeter reads 2 V. V Use the formula R = to calculate the resistance of R. I Give the unit of your answer. working resistance = … unit … [2] (c) Two pieces of wire, P and Q, with the same length and made of the same alloy, are connected in parallel between X and Y. The current in wire P is 5 A. The ammeter reading is 7 A. (i) Predict the current in wire Q. Give a reason for your answer. current in wire Q = … A reason … … [1] (ii) Deduce why different currents flow in wires P and Q. Give reasons for your answer. … … … … [2]

6 marks

Mark scheme: 9(a) any two from one or two metals or alloys (other than copper) graphite / carbon 1 9(b) = 2 / 0.5 = 4 ; ohms / Ω ; 2 9(c)(i) (2 A) sum of currents in parallel branches = current from source ; 1 9(c)(ii) P and Q have different resistances / thicknesses ; P less resistance than Q / P is thicker than Q ; 2

This question in 0653/41 May/June 2017

6 Fig. 6.1 shows a fan heater used to heat a room in cold weather. Fig. 6.1 The fan heater is connected to the mains electricity supply. Fig. 6.2 shows the circuit diagram for the fan heater. The fan heater has two heating elements, heater 1 and heater 2, and a motor to drive the fan, connected to a 240 V mains electricity supply. 240 V switch 3 heater 1 switch 1 heater 2 switch 2 M motor Fig. 6.2 (a) Deduce which switch or switches must be closed (on) for heater 1 and the motor to work without heater 2. … [1] (b) (i) Each heating element has a power consumption of 1100 W. Calculate the current through one heating element when switched on. State the formula that you use and show your working. formula working current = … A [2] (ii) The fan motor is rated at 50 W. The fuse in the circuit is rated at 10 A. Explain whether this fuse provides good protection if an overload happens. … … … [2] (c) An electrician wants to measure the current through the fan motor. Complete the circuit diagram in Fig. 6.3 to show how the electrician should connect a meter to do this. You should use the correct symbol for the meter to be used, and complete all missing circuit connections. 240 V switch 3 heater 1 switch 1 heater 2 switch 2 M motor Fig. 6.3 [2]

7 marks

Mark scheme: 6(a) (both) switch 1 and switch 3 ; 1 6(b)(i) P = V × I (or rearranged) / 1100 / 240 ; = 4.58 or 4.6 A ; 2 6(b)(ii) (if everything switched on) then 9.4 A / 2250 W / 0.21 A seen in calculation ; correct comparison of total current with fuse rating ; 2 Q Question 6(c) correc amme ct symbol for am eter in fan motor mmeter ; r branch, all circ cuit connections Answer complete ; Mar ks 2

This question in 0653/41 Oct/Nov 2017

9 In a theatre, spotlights are used to shine a beam of light on one person on the stage. Fig. 9.1 shows a spotlight shining a parallel beam of light on a singer. Fig. 9.1 (a) Fig. 9.2 shows a powerful lamp shining through a narrow hole in front of a lens inside the spotlight. Fig. 9.2 On Fig. 9.2 use a ruler to draw three rays that come through the narrow hole, pass through the lens and emerge parallel to each other to form a narrow beam of light. One ray has been started for you. [2] (b) Fig. 9.3a shows the way the lamps in two identical spotlights are connected to the electricity supply. The circuit contains a dimmer control so that the brightness of the lights can be changed. Fig. 9.3b shows part of the circuit diagram for this. dimmer control Fig. 9.3a power supply X Y Fig. 9.3b (i) The dimmer control contains a variable resistor. On Fig. 9.3b complete the circuit diagram by connecting the variable resistor into the circuit between X and Y using the correct circuit symbol. [1] (ii) The dimmer control is set so that the current through one of the lamps is 10 A. State the current in the main circuit. Explain your answer. current = … A explanation … … [2] (iii) The filament of one of the lamps breaks. State what will happen to the other lamp. Give a reason for your answer. … … … [1] (c) One lamp has a label as shown in Fig. 9.4. Voltage = 240 V Maximum power = 3000 W Fig. 9.4 (i) Use the formula P = IV to calculate the maximum current through the lamp. Show your working. current = … A [1] (ii) Describe how to set the variable resistor in the dimmer control to provide maximum power in the lamp. … … [1]

8 marks

Mark scheme: 9 9 9(a) two m all ray 9(b)(i) correc 9(b)(ii) 20 A ; becau 9(b)(iii) remai still a 9(c)(i) I = P 9(c)(ii) the id more rays from h ys emerge from ct symbol showi ; use lamps in par ins lit (no mark) complete circuit / V = 3000 / 240 dea that the resis hole to lens with lens reasonably ing variable resis rallel / current is t through that br 0 = 12.5 (A) ; stance in the dim at least one add y parallel ; stor ; shared / current ranch / reference mmer must be de ditional arrow co t in main circuit = e to parallel circu ecreased / turn c orrectly shown ; = sum ; uit / owtte ; control to minimu um resistance ; 2 1 2 1 1 1

This question in 0653/42 Oct/Nov 2017

6 Fig. 6.1a shows an insulated bag used to carry frozen food from the shop to home. Fig. 6.1b shows the structure of the walls of the bag. plastic covering insulating foam aluminium Carry– keep cool! foil Fig. 6.1a Fig. 6.1b (not to scale) (a) The insulating foam is designed to reduce thermal energy transfer through the bag. It has many small pockets of trapped gas which reduce conduction of thermal energy. (i) Describe how thermal energy is transferred through solids by conduction. … … … [1] (ii) Suggest why the trapped gas is less able to transfer thermal energy by conduction. … … [1] (b) The aluminium foil also helps to reduce thermal energy transfer. Name the method of thermal energy transfer reduced by the use of aluminium foil. … [1] (c) The food is transferred from the insulated bag into a refrigerator. The refrigerator has an electric motor with a power input of 80 W when connected to a 240 V mains supply. (i) Calculate the current through the electric motor. State the formula you use and show your working. formula working current = … A [2] (ii) Calculate the energy used by the refrigerator when the motor runs for one hour. State the formula you use and show your working. formula working energy = … J [2]

7 marks

Mark scheme: 6(a)(i) atoms / molecules / particles vibrate (faster) and / transfer this vibration / energy to neighbouring particles owtte ; 1 6(a)(ii) gas molecules far apart, no vibration ; 1 6(b) radiation ; 1 6(c)(i) P = IV ; (or alternative expression) / I = 80 / 240 ; = 0.33 (A) ; 2 6(c)(ii) E = P × t / E = V × I × t / E = 80 × 3600 ; = 288 000 (J) ; 2

This question in 0653/43 Oct/Nov 2017

6 Fig. 6.1 shows two people talking to each other using cordless telephones over a link to a communications satellite. communications satellite person 1 person 2 satellite satellite handset handset dish dish copper wires base base telephone telephone station station exchange exchange Fig. 6.1 (a) The conversation between the base stations and the satellite dishes is transmitted by electric currents in copper wires. These electric currents change rapidly when each person speaks. Define current and suggest what is happening in terms of particles in a copper wire when a changing current passes through it. … … … [2] (b) One person is speaking. Information is transmitted at frequencies of 300 Hz and 2.8 × 109 Hz at different stages in the communications system. Identify the stage at which each of these frequencies is being used, and state the type of wave involved. (i) A frequency of 300 Hz. … … [2] (ii) A frequency of 2.8 × 109 Hz. … … [2] (c) When a satellite telephone is used, there is a delay of about 0.1 s between one person speaking and the other person hearing. Explain why this delay happens. … … … [2]

8 marks

Mark scheme: 6(a) the idea that current is flow of (electrical) charge ; identifies the charge carriers as electrons ; 2 6(b)(i) between mouth and handset / handset and ear ; sound waves ; 2 Question Answer Marks 6(b)(ii) between handset and base station / satellite dish and satellite ; microwaves or radio waves ; 2 6(c) the idea that waves (of any kind) have an associated speed of travel ; the idea that waves / signals will take time to cover distance ; reference to great distance / high speed of emr : max 2

This question in 0653/42 Feb/March 2018

9 Fig. 9.1 shows a small electric cooker with two hot plates. hot plates Fig. 9.1 The cooker is connected to a 240 V supply. The plug contains a fuse with a rating of 13 A. Each hot plate is controlled by a switch and a variable resistor. Each hot plate can be turned on and off and controlled without affecting the other hot plate. (a) (i) In Table 9.1 draw the circuit symbols for each component used in the cooker circuit. Table 9.1 component fuse switch variable resistor symbol [2] (ii) Name the type of circuit connection that will allow each hot plate to be controlled separately by its own switch. … [1] (iii) Use the information about the cooker to draw a circuit diagram for the cooker. Use the circuit symbol for a heater to represent a hot plate: The circuit diagram has been started for you. 240 V supply [4] (b) The larger hot plate is rated at a maximum of 1.5 kW, and the smaller hot plate is rated at a maximum of 1.0 kW. Show by calculation that the 13 A fuse in the plug will not blow when the cooker is used with both hot plates at maximum rating. State the formula you use and show your working. formula working [3]

10 marks

Mark scheme: 9 9( 9( (a)(i) fuse switch variab 3 corre Any 1 (a)(ii) paralle (a)(iii) two ho each h each h fuse in le resistor ect for 2 marks correct for 1 ma el ; otplates connect hotplate branch hotplate branch n main circuit ; ark ted in parallel ; contains a varia contains a switc able resistor in se ch in series ; eries ; 2 1 4 Question Answer Marks 9(b) P = V × I ; EITHER larger hotplate: I = 1500 / 240 = 6.25 A smaller hotplate: I = 1000 / 240 = 4.17 A ; total current = 10(.4 A), (safely less than 13 A ) ; or total power = 1.5 (kW) + 1.0 (kW) = 2.5 (kW) ; P = V × I or I = P / V or total current = 2500 / 240 ; = 10(.4 A) (safely less than 13 A) ; 3

This question in 0653/41 May/June 2018

3 Fig. 3.1 and Fig. 3.2 show two circuit diagrams each connected to operate an electric motor and a lamp. 2 × 1.5 V cells 240 V mains supply C M M motor motor Fig. 3.1 Fig. 3.2 (a) Identify component C and explain why it is necessary in the circuit in Fig. 3.2, but not in the circuit in Fig. 3.1. component C … explanation … … … … [3] (b) (i) In Fig. 3.1, when the motor is switched on, but the lamp is not, a current of 0.2 A flows through the motor. Calculate the resistance of the motor. State the formula you use and show your working. formula working resistance = … Ω [2] (ii) In Fig. 3.2, the motor has a power rating of 20 W and the lamp has a power rating of 100 W. Calculate the current in the main circuit when both the motor and the lamp are switched on. State the formula you use and show your working. formula working current = … A [3] (c) A lamp is placed in front of a mirror. A student tries to look at the reflection of the lamp in the mirror, as shown in Fig. 3.3. lamp mirror Fig. 3.3 On Fig. 3.3, complete the ray diagram to show whether the student can see the image of the lamp in the mirror or not. [1]

9 marks

Mark scheme: 3(a) fuse ; (the idea that 240 V could produce a) high current ; one from (a high current could) cause damage / overheating ; (fuse) protects circuit / breaks circuit / melts ; 3 3(b)(i) (R = V / I) = 3 / 0.2 ; = 15 (Ω) ; 2 3(b)(ii) total power supply required = 100 + 20 = 120 W ; P = I × V or total current = 120 / 240 ; = 0.5 A ; 3 Question Answer Marks 3(c) reflected ray shown at approx. correct angle missing the eye ; 1

This question in 0653/42 May/June 2018

9 Fig. 9.1 shows an electric toaster used for toasting bread slices in a hotel dining room. control knobs for heating elements control knob for electric motor Fig. 9.1 The two heating elements inside, one to toast each side of the bread, are connected in parallel. They are each controlled by a switch. An electric motor carries the bread slices on a moving rack between the heating elements. The motor is controlled by a third switch and is connected in parallel with the heating elements. The plug at the end of the cable has a fuse inside, and is plugged into a 240 V mains supply. (a) The circuit symbols for each of these components used in the toaster circuit are: electric motor fuse heating element switch M Use the information about the toaster to draw a circuit diagram for the toaster. The circuit diagram has been started for you. 240 V [4] (b) The two heating elements are each rated at 240 V, 1.2 kW. The electric motor is rated at 240 V, 100 W. The plug has a 10 A fuse fitted. Show by calculation that the fuse in the plug is not adequate when both heating elements and the motor are in operation. Show your working. [3] (c) A smoke alarm is fitted in the dining room in case the toaster causes a fire. When it goes off, the smoke alarm has to make a loud high-pitched sound that everyone can hear. The highest frequency of sound some older residents can hear is 5 kHz below the top of the normal human hearing range. Suggest a frequency for the high-pitched sound from the smoke alarm that all residents should be able to hear. Give a reason for your answer. suggested frequency … kHz reason … … … [2]

9 marks

Mark scheme: 9(a) fuse in main circuit ; heating elements in parallel with each other and supply ; motor in parallel with heating elements (and supply) ; switches in series with both heaters and motor ; 4 9(b) total power supply required = 1200 × 2 + 100 = 2500 W ; use of P = I × V e.g. current through one heater = 5 A / total current = 2500 ÷ 240 ; = 10.4 A (which is above fuse rating) ; 3 Question Answer Marks 9(c) value within range 10–15 kHz ; top end of normal range is 20 kHz / older residents can hear up to 15 kHz ; 2

This question in 0653/43 May/June 2018

9 Fig. 9.1 shows a display refrigerator for storing cold drinks in a shop. Fig. 9.1 The refrigerator uses electrical energy • for a lamp to light up the inside of the refrigerator • to power an electric motor to run the cooler in the refrigerator. The circuit symbol for an electric motor is: M Fig. 9.2 shows part of the circuit diagram for the refrigerator. Fig. 9.2 (a) When the shop is closed, the lamp is switched off, but the electric motor needs to continue to run the refrigerator to keep the contents cool. (i) On Fig. 9.2 complete the circuit diagram for the refrigerator that will allow the lamp to be switched off while the electric motor remains on. [3] (ii) Name the circuit component with the symbol … [1] (b) The potential difference across the lamp is 240 V, and its power consumption is 40 W. The potential difference across the motor is 240 V and its power consumption is 300 W. Calculate the total current from the supply through the refrigerator. State the formula you use and show your working. formula working current = … A [3]

7 marks

Mark scheme: 9(a)(i) correct symbol for lamp ; parallel circuit with motor in one branch, lamp in other branch and no short circuit and no additional components ; switch in series with lamp only ; 3 9(a)(ii) mains supply / (a.c.) power supply ; 1 9(b) use of P = IV / I = P / V ; (total) P = 40 + 300 = 340 W ; (I = 340 / 240) = 1.42 / 1.4 (A) ; or use of P = IV / I = P / V ; 40 / 240 + 300 / 240 ; = (0.17 + 1.25) = 1.42 (A) / 1.4 (A) ; 3

This question in 0653/43 Oct/Nov 2018

9 In many cities, sodium street lamps are used at night. These lamps produce an intense yellow light. (a) A street is lit by eight identical sodium lamps using mains voltage of 240 V. The current in each lamp is 0.50 A. The street is lit for 12 hours during the night. Calculate the electrical energy used. Show your working. energy = … J [3] (b) A sodium street lamp emits electromagnetic radiation as yellow light with a wavelength of 589 × 10−9 m. (i) State the speed at which electromagnetic waves travel. speed = … m / s [1] (ii) Use your answer to (b)(i) to calculate the frequency of the yellow light emitted by a sodium lamp. Show your working. frequency = … Hz [2] (c) Electromagnetic radiation and water waves are examples of transverse wave motion. Sound is an example of longitudinal wave motion. Describe one way in which a longitudinal wave differs from a transverse wave. … … [1] (d) Table 9.1 shows some of the wavelengths of electromagnetic radiation emitted by another type of street lamp called a mercury-vapour lamp. Table 9.1 wavelength / 10−9 m colour 184 not visible 404 violet 436 blue 546 green 578 yellow-orange (i) Use information in Table 9.1 to suggest the part of the electromagnetic spectrum where a wavelength of 184 × 10−9 m is likely to be found. Give a reason for your answer. part of spectrum … reason … … [1] (ii) Describe a danger to human health if this wavelength is not removed when mercury-vapour lamps are used near people. … … [1] [Total: 9]

9 marks

Mark scheme: 9(a) time in seconds = 60 × 60 × 12 / 43200 ; E = 240 × 0.5 × 8 × 60 × 60 × 12 = 41 472 000 J / 41(.5) MJ ; 3 9(b)(i) 3.0 × 108 m / s ; 1 9(b)(ii) v = fλ ; f (= v / λ) = 3 × 108 / 589 × 10–9 = 5.09 × 1014 (Hz) ; 2 9(c) transverse wave vibrations at right angles to direction of travel, longitudinal in same direction as direction of travel ; 1 9(d)(i) (ultraviolet) shorter wavelength than violet / visible ; 1 9(d)(ii) skin cancer / burning of skin / other known hazard ; 1

This question in 0653/42 Feb/March 2019

6 Fig. 6.1 shows an electrical device used in kitchens to kill insects. Insects can spread disease by contaminating food. fine wires in front of fluorescent tubes the fluorescent tubes safety grille consisting of closely spaced metal rods Fig. 6.1 The device is connected to the electricity supply. (a) Fig. 6.1 shows several fine wires in front of the two fluorescent tubes. The insects have to fly between the wires as they go towards the light. A potential difference of 2000 V exists between each pair of wires. When an insect touches two wires at once, it completes an electric circuit. A current of 0.50 A flows through the insect for 0.10 s. (i) Calculate the energy transferred to the insect. Show your working. energy = … J [2] (ii) Calculate the total electric charge that passes through the insect. Show your working and give the unit of your answer. charge = … unit … [3] (b) The fluorescent tubes emit ultraviolet radiation that can be seen by many insects. This attracts them to the device. The wavelength of the ultraviolet radiation is 184 × 10–9 m. The speed of electromagnetic radiation is 3.0 × 108 m / s. Calculate the frequency of the ultraviolet radiation emitted. Show your working. frequency = … Hz [2] (c) Suggest why a grille of metal rods is placed across the front of the device. … … [1] [Total: 8]

8 marks

Mark scheme: 6(a)(i) = 100 (J) ; 2 6(a)(ii) (Q =) It = 0.5 × 0.1 ; = 0.05 ; coulomb(s) / C ; 3 6(b) v = fλ or f = v/λ or f = 3.0 × 108 / 184 × 10-9 ; = 1.6(3) × 1015 (Hz) ; 2 Question Answer Marks 6(c) to protect humans from touching the high voltage wires / owtte ; 1

This question in 0653/41 May/June 2019

8 (a) Complete the sentence: An electric current in a metal is a flow of … , which carry negative … . [2] (b) A battery has an e.m.f. of 24 V. (i) Use the formula E = IVt to calculate the energy E transferred from the battery when a current of 50 A flows for 1 hour. Show your working. energy = … J [2] (ii) Calculate the electric charge that flows when a current of 25 A flows for 60 s. Show your working and state the unit of your answer. charge = … unit … [3] (c) The battery is used to operate the starter motor on a truck. The battery is also used to operate the lights on the truck. The starter motor must have its own switch and operate independently from the lights. Fig. 8.1 shows part of the electrical circuit of the truck. Fig. 8.1 The symbol for the starter motor is M On Fig. 8.1, complete the circuit diagram to show how the starter motor and a switch should be included in this circuit. [1] [Total: 8]

8 marks

Mark scheme: 8(a) electrons ; charges ; 2 8(b)(i) 1 hour = 3600 s / (E =) 50 × 24 × 3600 ; 4 320 000 (J) ; 2 8(b)(ii) (Q=) I × t or (Q =) 25 × 60 ; = 1500 ; coulombs / C ; 3 8(c) motor symbol with switch connected in parallel with lamps ; 1

This question in 0653/43 May/June 2019

9 (a) Fig. 9.1 shows a circuit containing three resistors, R1, R2 and R3. V R1 R3 A R2 Fig. 9.1 (i) R1 has a value of 8.0 Ω. R2 has a value of 3.0 Ω. R3 has a value of 6.0 Ω. Complete steps 1 and 2 to calculate the value of the combined resistance of the three resistors in this circuit. Show your working. Step 1: Calculate the combined resistance of R2 and R3. Ω combined resistance of R2 and R3 = … Step 2: Calculate the total resistance of the three resistors. total resistance = … Ω [3] (ii) The reading on the ammeter is 2.7 A. The current in R2 is 1.8 A Determine the current in R3. Show your working. current = … A [1] (iii) Explain your answer to (a)(ii). … … [1] (iv) With the switch closed and the current flowing in the circuit, the reading on the voltmeter is 27 V. The switch is opened, so no current flows in the circuit. The reading on the voltmeter increases to 30 V. Suggest an explanation for this observation. … … [1] (b) A circuit with a total resistance of 5.0 Ω has a current of 9.0 A. Calculate the power consumed in the circuit. Show your working. power = … W [2] [Total: 8]

8 marks

Mark scheme: 9(a)(i) (1/3 + 1/6 or 3/6 Æ) combined R = (6/3) = 2 Ω ; total R = 8 + 2 = 10 Ω ; 3 9(a)(ii) 2.7 – 1.8 = 0.9 (A) ; 1 9(a)(iii) current from the source (ammeter reading) is the sum of the currents in the separate branches (in R2 and R3) of a parallel circuit / owtte ; 1 9(a)(iv) must be resistance inside the battery / resistance of connecting wires / the idea of greater resistance ; 1 9(b) use of P = VI or P = I2R ; (45 × 9 or 92 × 5) = 405 W ; 2

This question in 0653/41 Oct/Nov 2019

9 Fig. 9.1 shows a lightning bolt, which is a form of electrostatic discharge. thundercloud lightning bolt Fig. 9.1 (a) Fig. 9.2 shows the range of wavelengths of different parts of the electromagnetic spectrum. < 0.001 0.001–1 1–450 400–750 750 × 10–9 m 0.001– > 1.0 m × 10–9 m × 10–9 m × 10–9 m × 10–9 m – 0.001 m 1.0 m gamma X-rays microwaves rays Fig. 9.2 A lightning bolt emits a range of wavelengths between 390 nm and 590 nm. (1 nm = 1 × 10–9 m). Identify the two parts of the electromagnetic spectrum emitted by lightning. On Fig. 9.2 fill in the missing names of these parts in the correct places. [2] (b) A person hears the thunder from a distant lightning bolt 10.0 s after the lightning is seen. Sound travels in air at 330 m / s. Calculate the distance of the person from the lightning bolt. distance = … m [2] (c) Lightning bolts occur when clouds become highly charged and a very high voltage exists between the thundercloud and the ground. The current in a lightning bolt is 30 000 A, and flows for 0.000050 s Calculate the electric charge that passes to Earth from this lightning bolt. Show your working, and give the unit of your answer. charge = … unit … [3] (d) (i) The thundercloud consists mainly of water droplets. The droplets at the bottom are negatively charged and at the top are positively charged. Name the type of particle exchanged between the droplets to produce the charges on them. … [1] (ii) Just before a thunderstorm, some people find that their hair is standing on end. Suggest a reason for this. Explain your answer. reason … explanation … … [2] [Total: 10]

10 marks

Mark scheme: 9(a) visible light in correct position ; ultraviolet in correct position ; 2 9(b) use of distance = speed × time ; (330 × 10) = 3300 m ; 2 9(c) use of Q = I t ; (30 000 × 0.00005) = 1.5 ; coulombs / C ; 3 9(d)(i) electron(s) ; 1 9(d)(ii) hair becomes (electrostatically) charged (due to transfer of electrons) ; like charges repel (causing hair to stand on end) ; 2

This question in 0653/42 Oct/Nov 2019

9 Fig. 9.1 shows an electric lawnmower that is used for cutting grass. power cable lawnmower grass Fig. 9.1 The lawnmower operates from a 230 V mains electricity supply. The circuit in the lawnmower contains: • an electric motor • a switch to switch the motor on and off • a lamp to show when the motor is switched on • a variable resistor to vary the current in the motor but not the current in the lamp • a fuse to protect the circuit. (a) On Fig. 9.2, complete the circuit diagram for the lawnmower. 230 V supply M motor Fig. 9.2 [4] (b) The current in the lamp is 0.25 A. The potential difference across the lamp is 230 V. Calculate the resistance of the lamp. resistance = … Ω [2] [Total: 6]

6 marks

Mark scheme: 9(a) 9(b) V = IR in any form / 230 ÷ 0.25 ; 920 (Ω) ; 2 switch and fuse symbols correct ; variable resistor symbol correct ; switch and fuse in main circuit ; variable resistor in motor branch ;

This question in 0653/41 Oct/Nov 2020

9 Fig. 9.1 shows a car powered by a battery. The battery supplies electrical energy to two identical electric motors, one for each front wheel. Fig. 9.1 The two motors are connected in parallel. Both motors are controlled by the same variable resistor. (a) On Fig. 9.2 complete the circuit diagram with two motors, one switch and one variable resistor. Use M as the symbol for an electric motor. Fig. 9.2 [3] (b) The potential difference (p.d.) across each motor when used at maximum power is 96 V. The maximum power supplied to one motor is 24 kW. (i) Calculate the current through the motor when at maximum power. current = … A [2] (ii) Show that the current supplied by the battery when both motors are at maximum power is 500 A. [1] (c) The car battery is recharged from an electricity supply with a current of 30 A. It takes 4 hours (14 400 seconds) to recharge the battery. Calculate the total electric charge required to recharge the battery. State the unit of your answer. charge = … unit … [3] [Total: 9]

9 marks

Mark scheme: 9(a) switch and variable resistor symbols correct ; variable resistor and switch in main circuit ; parallel connection for two motors ; 3 9(b)(i) Power = I × V OR I = P ÷ V = 24 000 ÷ 96 ; = 250 (A) ; 2 9(b)(ii) the idea that the current in the main circuit = sum of currents in branches ; 1 9(c) Q = It / 30 × 14 400 ; = 432 000 ; coulombs / C ; 3

This question in 0653/42 May/June 2021

9 Fig. 9.1 shows a car travelling forwards along a road. metal car body rubber tyres Fig. 9.1 As the car drives along, electrostatic charges build up on the car. (a) (i) State what causes an electrostatic charge to form on the car. … [1] (ii) Name the particles transferred when an electrostatic charge builds up on the car. … [1] (iii) Explain why the electric charge does not travel to the ground while the car is being driven along the road. … … … [2] (b) When the car stops, the driver gets out and touches the metal car body. The electric charge on the car travels through the driver to the ground. The electric current through the driver as the charge travels to the ground is 0.015 A and lasts for 0.3 ms. (i) Calculate the total electric charge that travels through the driver. charge = … C [2] (ii) The total resistance of the driver’s body and shoes is 40 000 Ω. Show that the potential difference between the driver and the car before she touches the door handle is 600 V. [1] [Total: 7]

7 marks

Mark scheme: 9(a)(i) friction ; 1 9(a)(ii) electrons ; 1 9(a)(iii) tyres made of rubber ; (rubber is) an insulator ; 2 9(b)(i) Q = It = 0.015 × 0.3 / 1000 ; = 0.000 004 5 (C) ; 2 9(b)(ii) V = IR = 0.015 × 40 000 (= 600 V) ; 1

This question in 0653/43 May/June 2021

9 A student connects a heater and four identical lamps to a battery. Fig. 9.1 shows the circuit. heater Fig. 9.1 (a) There is a current of 8.5 A in the heater. There is a current of 1.5 A in each lamp. Calculate the total current in the battery. total current = … A [2] (b) State the name of the instrument used to measure current. … [1] (c) A student has two switches, S1 and S2, and a fuse. The student changes the circuit so that: • switch S1 controls the heater but does not control the lamps • switch S2 controls all four lamps but does not control the heater • the fuse protects the whole circuit. On Fig. 9.2, complete the circuit diagram to show how the student connects the circuit. heater Fig. 9.2 [4] [Total: 7]

7 marks

Mark scheme: 9(a) total current = sum of branches / 8.5 + 1.5 + 1.5 ; 11.5 (A) ; 2 9(b) ammeter ; 1 9(c) correct symbols for fuse AND switch ; switch S1 in correct place for heater ; switch S2 in correct place for lamps ; fuse in correct place AND no short circuits, open circuits or additional components ; 4 S1 S2

This question in 0653/41 Oct/Nov 2021

9 Fig. 9.1 shows some electrical components of a car. battery starter motor headlamps Fig. 9.1 Fig. 9.2 shows a circuit diagram for the components. M starter motor headlamps Fig. 9.2 (a) State one advantage of connecting the headlamps in parallel. … … [1] (b) One headlamp requires a current of 5 A. The headlamp is switched on for five hours. Calculate the total charge that flows through the headlamp in this time. charge = … C [3] (c) The circuit is changed to include two switches, S1 and S2. • Switch S1 controls the starter motor but does not control the headlamps. • Switch S2 controls both the headlamps but does not control the starter motor. On Fig. 9.3, complete the circuit diagram to include switches S1 and S2. M starter motor Fig. 9.3 [3] [Total: 7]

7 marks

Mark scheme: 9(a) if one (head)lamp breaks, the other still works / still a complete circuit ; 1 9(b) correct time conversion / 5 × 60 × 60 / 18 000 ; Q = It in any form / 5 × 18 000 / 5 × 5 × 60 × 60 ; 90 000 (C) ; 3 9(c) switch S1 for starter motor in correct position ; switch S2 for headlamps in correct position ; switch symbols correct AND no short circuits, open circuits or additional components ; 3

This question in 0653/43 Oct/Nov 2021

9 Fig. 9.1 shows an electric circuit. variable resistor switch lamp voltmeter battery ammeter Fig. 9.1 (a) The switch is turned on, and the variable resistor adjusted until the voltmeter reading is 6.0 V. The ammeter reading is 0.75 A. (i) Calculate the resistance of the lamp. resistance = … Ω [2] (ii) Calculate the power of the lamp. power = … W [2] (b) On Fig. 9.2, complete the circuit diagram for the circuit shown in Fig. 9.1. A Fig. 9.2 [3] [Total: 7]

7 marks

Mark scheme: 9(a)(i) 8.0 () ; 2 9(a)(ii) Power = V  I (in any form) / = 6.0  0.75 ; 4.5 (W) ; 2 9(b) correct symbols for switch AND voltmeter ; correct symbol for variable resistor ; complete circuit with voltmeter parallel to lamp only and swich correctly positioned; 3

This question in 0653/41 May/June 2022

6 (a) Fig. 6.1 shows a hairdryer. switch plug Fig. 6.1 The hairdryer contains an electric motor to blow air and a heater to heat the air. The plug contains a fuse. Fig. 6.2 shows the circuit diagram for the hairdryer. 240 V fuse a.c. power supply switch heater M motor Fig. 6.2 (i) The electric motor has a power rating of 60 W. The heater has a power rating of 2300 W. Show that the current in the fuse is 9.8 A. [3] (ii) Discuss whether 10 A is an appropriate rating for the fuse. … … … [2] (b) Fig. 6.3 shows a different hairdryer with two switches. switch S1 switch S2 Fig. 6.3 When switch S1 is ON and switch S2 is ON, the hairdryer blows out heated air. When switch S1 is ON and switch S2 is OFF, the hairdryer blows out unheated air. When switch S1 is OFF, both the motor and the heater are switched OFF. Fig. 6.4 shows an incomplete circuit diagram for the hairdryer. 240 V a.c. power supply heater M motor Fig. 6.4 On Fig. 6.4, complete the circuit diagram for the hairdryer by adding switch S1 and switch S2 in the correct positions. Label the switches S1 and S2. [2] [Total: 7]

7 marks

Mark scheme: 6(a)(i) evidence of, power = current  voltage ; 3 fan current = 60 ÷ 240 = 0.25 A / heater current = 2300 ÷ 240 = 9.58 A ; current in fuse = 0.25 + 9.58 = 9.83 A ; OR evidence of, power = current  voltage ; total power drawn = 2300 + 60 / 2360 W ; current in fuse = 2360 ÷ 240 = 9.83 A ; 6(a)(ii) comparison of fuse rating with operating current, e.g. rating is, higher than / too close to, operating current ; 2 appropriate matching conclusion, e.g. so fuse, does not blow / may blow, under normal operation ; 6(b) 2 switch S1 in main circuit ; switch S2 in heater branch ;

This question in 0653/41 Oct/Nov 2022

6 Fig. 6.1 shows an electric heater with two heating elements connected to a 240 V supply. heating element 2 heating element 1 Fig. 6.1 Fig. 6.2 shows the circuit diagram for the heater. 240 V a.c. power supply switch variable resistor heating element 2 heating element 1 Fig. 6.2 Heating element 1 has a resistance of 72 Ω. Heating element 2 has a resistance of 36 Ω. (a) The heater is switched on. The variable resistor is set to have zero resistance. (i) Show that the combined resistance of the two heating elements is 24 Ω. [2] (ii) Calculate the current from the supply. current = … A [2] (b) The resistance of the variable resistor is increased. Explain the effect this has on the total thermal energy output from the heater. … … … … [3] (c) Fig. 6.3 shows the structure of a heating element. wire wound into a coil Fig. 6.3 The wire in heating element 2 is the same length as the wire in heating element 1. The wire in heating element 2 is the same material as the wire in heating element 1. Describe how heating element 2 has a lower resistance than heating element 1. … … … [2] [Total: 9]

9 marks

Mark scheme: 6(a)(i) 1 1 1 2 evidence of, = + ; R T R1 R 2 72 × 36 2592 72 1 1 / / / + (= 24 ) ; 72 + 36 108 3 72 36 6(a)(ii) evidence of, R = V ÷ I / 240 ÷ 24 ; 2 10 (A) ; 6(b) (total resistance increases so) current decreases ; 3 current decreases so thermal energy output decreases ; evidence of, P = V I / E = V I t ; 6(c) resistance is inversely proportional to cross-sectional area ; 2 wire in element 2 has greater cross-sectional area ;

This question in 0653/42 Oct/Nov 2022

9 Fig. 9.1 shows a circuit diagram for an electric doorbell. 6.0 V bell push switch electric bell Fig. 9.1 A potential difference of at least 6.0 V is needed to make the bell ring and the lamp light. The wires connecting the bell to the rest of the circuit are 1.0 m long. A battery is included in the circuit giving a voltage of 6.0 V. The current in the bell is 0.75 A when it rings. (a) (i) Calculate the resistance of the bell. resistance = … Ω [2] (ii) The voltage provided by the battery is checked using a voltmeter. The voltmeter is connected so that the bell push does not affect the reading. On Fig. 9.1, add a voltmeter symbol to show how the voltmeter is connected. [2] (b) The length of wire connecting the bell to the rest of the circuit is increased from 1.0 m to 100 m. The lamp lights but the bell does not work. Suggest why the bell no longer works, but the lamp still works. … … … [2] [Total: 6]

6 marks

Mark scheme: 9(a)(i) 8(.0) () ; 9(a)(ii) correct symbol connected in parallel ; connection to right of battery made between battery and bell push ; 2 9(b) resistance of wiring increases with length / idea that resistance in the bell branch is too high ; p.d. across bell now less (than 6.0 V while still 6.0 V across lamp) / current in the bell decreases ; 2

This question in 0653/42 May/June 2023

6 Fig. 6.1 shows an electric fan and a lighting unit with two lamps, connected to a car battery. The fan blades rotate and blow cool air when the fan is switched on. car battery lighting unit switch fan switch Fig. 6.1 (a) State the type of circuit connection for the fan and lighting unit. … [1] (b) State the form of useful energy output by the working fan. … [1] (c) The battery supplies a voltage of 12.0 V. The current from the battery is 8.0 A. The power rating of the lighting unit is 11 W. (i) Show that the current in the lighting unit is 0.92 A. [1] (ii) Calculate the power rating of the fan. power … W [2] (d) The circuit should also contain a fuse to protect the components. A fuse rated at 10 A is added into the main circuit. Explain why this fuse: • will give protection to the fan • will not give protection to the lighting unit. … … … … [1] (e) Fig. 6.2 shows an incomplete circuit diagram for the circuit in Fig. 6.1. The light fitting contains two lamps in series. The fan contains an electric motor. The complete circuit needs two fuses. M electric motor Fig. 6.2 On Fig. 6.2, complete the circuit diagram to include: • the second lamp • one fuse to protect the fan • one fuse to protect the lamps • the battery and all connecting wires. [3] [Total: 9]

9 marks

Mark scheme: 6(a) parallel ; 1 6(b) kinetic energy (of rotating blades / blown air) ; 1 6(c)(i) power (rating of lamp) = V  I / (I =) 11  12 ; 1 6(c)(ii) (power rating of whole circuit = V  I =) 12  8.0 / 96 ; (power rating of fan = (12  8) – 11 =) 85 (W) ; OR (current in fan circuit =) 8.0 – 0.92 / 7.1 ; (power rating of fan = 12  7.1 =) 85(.2) (W) ; 2 Question Answer Marks 6(d) rating of fuse (10 A) much higher than lamp current but closer to the fan current OR fuse allows (up to) 10 A to flow with no damage to fan but causes damage to lamp ; 1 6(e) second lamp in series ; two fuse symbols correct, and one in each branch ; battery symbol and connecting wiring complete with no short circuits ; 3

This question in 0653/43 May/June 2023

6 (a) Fig. 6.1 shows an incomplete circuit diagram for the heater, two headlamps and two rear lamps in a car. 12 V heater headlamps rear lamps Fig. 6.1 (i) The headlamps and rear lamps are switched on at the same time by one switch, S1. The heater is switched on separately by switch S2. Complete and label the circuit diagram in Fig. 6.1 to show the positions of switches S1 and S2. [3] (ii) Fig. 6.2 shows the four lamps connected together. headlamps rear lamps Fig. 6.2 Each headlamp has a resistance of 7.0 Ω. Each rear lamp has a resistance of 3.5 Ω. Calculate the total resistance of the four lamps connected together. resistance = … Ω [3] (b) Fig. 6.3 shows the circuit for the starter motor of the car. car battery starter switch cable starter motor Fig. 6.3 (i) There is a current of 150 A in the starter motor. Calculate the charge that flows through the starter motor in 30 s. charge = … C [2] (ii) The cables in the circuit contain very thick copper wires. Suggest why the wires are very thick. … … … [2] [Total: 10]

10 marks

Mark scheme: 6(a)(i) one correct switch symbol ; 3 one switch labelled S2 in heater branch / switch labelled S1 between battery and lamps AND not in heater branch ; correct circuit with no extra components or short circuit ; 6(a)(ii) total resistance of rear lamps = 7.0 () / total resistance of headlamps = 14.0 () ; 3 evidence of, R = R1  R2  (R1 + R2) / 7.0  14.0  (7.0 + 14.0) ; 4.7 () ; 6(b)(i) evidence of, Q = I t / 150  30 ; 2 4500 (C) ; 6(b)(ii) large (cross-sectional) area means low resistance ORA ; 2 reference to the need to, carry a (very) high current / avoid overheating ;

This question in 0653/41 Oct/Nov 2023

9 Fig. 9.1 shows two identical floodlights, F and G, at a sports ground. floodlight F floodlight G Fig. 9.1 Fig. 9.2 shows a wind turbine used to generate electricity for the two floodlights. cables Fig. 9.2 The wind turbine generates an electromotive force (e.m.f.) of 240 V. There is a current of 18 A in each cable from the wind turbine. (a) Calculate the power output from the turbine. Give the unit of your answer. power = … unit … [3] (b) The two identical floodlights are connected to the wind turbine by cables. Table 9.1 gives information about the current in each floodlight, and the distance of each floodlight from the wind turbine. Table 9.1 current in floodlight distance from wind turbine floodlight / A / m F 12.0 200 G 6.0 400 (i) State the type of circuit connection from the wind turbine to the two floodlights. Give a reason for your answer. type of circuit connection … reason … … [2] (ii) Explain why the current in floodlight G is half the current in floodlight F. … … … … … [3] [Total: 8]

8 marks

Mark scheme: 9(a) evidence of, P =IV / 18  240 ; 3 4300 ; W / watt(s) ; 9(b)(i) parallel ; 2 different currents so two separate branches / series circuit must have same current everywhere / 18 A is split into 12 A and 6 A ; 9(b)(ii) cables to floodlight G are twice as long ; 3 R is proportional to length / R increases with length / R (of the cables / in the branch) is doubled ; idea that R is inversely proportional to I / use of V = IR (in any form) (so the current is halved) ;

This question in 0653/42 Oct/Nov 2023

9 Fig. 9.1 shows a circuit diagram for part of an electric dishwashing machine. 240 V heater motor M Fig. 9.1 (a) State the circuit component represented by the symbol . … [1] (b) The resistance of the heater is 25 Ω. (i) Calculate the current in the heater. current = … A [2] (ii) Use your answer to (b)(i) to calculate the power required by the heater. power = … W [2] (c) On Fig. 9.1, draw a lamp connected in the circuit that will only be on when the heater is switched on but will not reduce the current in the heater. [2] [Total: 7]

7 marks

Mark scheme: 9(a) a.c. power supply ; 1 9(b)(i) (R =) V  I in any form or 240  25 ; 9.6 (A) ; 2 9(b)(ii) (P =) V  I in any form or 240  9.6 ; 2300 (W) / 2.3 kW ; 2 9(c) lamp symbol connected in parallel with heater ; lamp symbol in parallel and connected to left of heater and to the left of the heater’s switch ; 2

This question in 0653/42 May/June 2024

9 Fig. 9.1 shows a simple circuit containing two identical lamps. cell 0 1 A ammeter lamps Fig. 9.1 (a) Complete these sentences. Potential difference is measured in units called … . The current in the circuit is a flow of … . [2] (b) The cell produces a total e.m.f. of 2.4 V. There is a current of 0.50 A in the circuit. (i) Calculate the power supplied by the cell. power = … W [2] (ii) The cell in Fig. 9.1 has a total charge of 9000 C. Calculate the maximum time in hours for which the cell can produce a current of 0.5 A. time = … h [3] (c) Fig. 9.2 shows the same circuit components connected in a different arrangement. A Fig. 9.2 (i) Describe how the circuit arrangement in Fig. 9.2 differs from that shown in Fig. 9.1. … … [1] (ii) Predict whether the reading on the ammeter in Fig. 9.2 will be greater or less than the ammeter reading in Fig. 9.1. Give a reason for your answer. … … [1] [Total: 9]

9 marks

Mark scheme: 9(a) volts ; electrons / charge ; 2 9(b)(i) power = V  I or 2.4  0.50 ; 1.2 (W) ; 2 9(b)(ii) Q = It or 9000 = 0.5  t or (t =) 9000 ÷ 0.5 ; (time = 9000  0.5) = 18 000 s ; seconds to hours = 5(.0) h ; 3 9(c)(i) lamps in parallel (instead of in series) ; 1 9(c)(ii) greater (no mark) (reason) less resistance or current from source / total current, is sum of (separate) currents in, each lamp / each branch ; 1

This question in 0653/43 May/June 2024

9 (a) State the name of the component with the electrical symbol shown. … [1] (b) Fig. 9.1 shows a circuit diagram for the two headlamps and two rear lamps of a car. 12 V A P A headlamps Q A rear lamps R Fig. 9.1 Both headlamps are identical. Both rear lamps are identical but different from the headlamps. Ammeter P reads 11.0 A. Ammeter R reads 1.0 A. (i) Determine the reading on ammeter Q. reading = … A [1] (ii) Use your answer to (b)(i) to determine the resistance of one headlamp. resistance = … Ω [3] (c) A motorcycle has one headlamp and one rear lamp. Each lamp is made from a length of filament wire. The wires in each lamp are made of the same metal. The wire in the rear lamp: • is three times the length of the wire in the headlamp • has half the cross-sectional area of the wire in the headlamp. The resistance of the headlamp of the motorcycle is 3.0 Ω. Determine the resistance of the rear lamp of the motorcycle. resistance = … Ω [3] [Total: 8]

8 marks

Mark scheme: 9(a) fuse ; 1 9(b)(i) (current in headlight branch = 11.0 – 1.0 =) 10.0 (A) ; 1 9(b)(ii) (current in one headlight = ½  10.0) = 5.0 (A) ; 3 evidence of, R = V ÷ I / 12 ÷ 5.0 ; 2.4 () ; alternative method: evidence of, R = V ÷ I or 12 ÷ 10.0 or 1.2() ; (resistance of parallel arrangement) 1.2  2 OR double the calculated resistance ; 2.4 (Ω) ; 9(c) resistance of wire proportional to length / 3 longer gives 3 resistance / 3  3 or 9 ; 3 resistance of wire inversely proportional to cross-sectional area / half cross-sectional area gives 2 resistance / 2  3 or 6 ; (resistance of rear lamp is 6 resistance of headlamp =) 18 () ;

This question in 0653/43 Oct/Nov 2024

9 Fig. 9.1 shows a circuit that contains an electric motor and a light‑emitting diode (LED) connected to a direct current (d.c.) power supply. A M Fig. 9.1 (a) When the motor is switched on, the LED lights up. (i) On Fig. 9.1, show the polarity of the terminals of the power supply using + and – signs. Give a reason why the + and – signs must be the way you have shown. … … [1] (ii) The power supply is 9.0 V. The reading on the ammeter is 6.6 A. The current in the LED is 0.30 A. Calculate the resistance of the motor. resistance = … Ω [3] (b) (i) State the name of the component with the electrical symbol shown. G ….…… … ………………………………………….………. [1] (ii) Complete the sentence to define electromotive force (e.m.f.). Electromotive force is the electrical …………………… done by a source in moving a unit ………………… around a complete circuit. [2] (c) The circuit in Fig. 9.1 is used in a satellite. (i) The satellite orbits the Earth at a distance of 15 000 km from the centre of the Earth. The orbital speed of the satellite is 17 km / s. Calculate the orbital period T of the satellite. T = … s [2] (ii) The satellite is used to study the Universe. State the approximate age of the Universe. … [1] [Total: 10]

10 marks

Mark scheme: 9(a)(i) 1 AND current only flows in one direction in LED / current only able to flow in this direction through LED ; 9(a)(ii) current in motor = 6.6 – 0.30 = 6.3 A ; 3 R = V÷I / 9.0 ÷ 6.3 ; 1.4 () ; 9(b)(i) generator ; 1 9(b)(ii) work ; 2 charge ; 9(c)(i) v = 2r ÷ T (in any form) / 2    15 000 ÷ 17 ; 2 5500 or 5.5  103 (s) ; 9(c)(ii) 13.8 billion years ; 1

This question in 0653/41 May/June 2025

9 (a) Complete the definition of potential difference (p.d.). Potential difference (p.d.) is the work done by a unit … moving between two points in a circuit. [1] (b) State the names of the electrical components with the symbols shown. … … [2] (c) A student assembles the circuit shown in Fig. 9.1. A Fig. 9.1 The student makes an error in the assembly of the circuit. The light-emitting diode (LED) does not emit light and the ammeter shows there is no current in the circuit. Identify the error in the assembly of the circuit. … … [1] (d) Two wires, A and B, are made of the same metal. Wire A has length 2.5 m, diameter 0.75 mm and resistance 0.16 Ω. Wire B has length 7.5 m and diameter 1.5 mm. Calculate the resistance of wire B. resistance = … Ω [3] (e) A satellite orbits the Earth with an orbital speed of 7800 m / s and an orbital period of 5400 s. The radius of the Earth is 6.38 × 106 m. Calculate the distance of the satellite above the Earth’s surface. distance = … m [3] [Total: 10]

10 marks

Mark scheme: 9(a) charge ; 1 9(b) variable resistor ; 2 heater ; 9(c) LED connected the wrong way round / AW ; 1 9(d) length 3 idea that R  L or B is 3 resistance of A seen or 0.48 / 0.16  3 ; seen area idea that R  A-1 / R  d -2 or B is ¼ / ½ 2  resistance of A or 0.04 / 0.16  0.25 ; seen 0.12 () ; 9(e) M1 v = 2r ÷ T or r = 7800  5400 ÷ 2 ; 3 M2 (radius of orbit of satellite =) 6.7  106 m ; M3 (distance above Earth = 6.7  106 – 6.380  106 =) 3.2  105 (m) ;

This question in 0653/41 Oct/Nov 2025

9 (a) State the names of the electrical components with the symbols shown. G … … [2] (b) A student assembles the circuit shown in Fig. 9.1. 15 Ω 12 Ω 24 Ω Fig. 9.1 The battery has an electromotive force (e.m.f.) of 9.0 V. (i) Define e.m.f. … … … [2] (ii) Calculate the combined resistance of the three resistors in the circuit. resistance = … Ω [3] (c) A student stands in front of a vertical plane mirror of length 40 cm, as shown in Fig. 9.2. plane mirror 40 cm NOT TO 130 cm SCALE x cm P Fig. 9.2 The vertical position of the mirror can be adjusted. • P is a point on the ground that is vertically below the student’s eyes. • The vertical distance between the student’s eyes and point P is 130 cm. • The vertical distance between the bottom of the mirror and the ground is x cm. Determine the smallest value of x at which it is possible for the student to see point P in the mirror. x = … cm [3] [Total: 10]

10 marks

Mark scheme: 9(a) generator ; 2 fuse; 9(b)(i) (electrical) work done (by a source) moving charge around a (complete) circuit ; 2 per unit charge / per coulomb ; 9(b)(ii) 1 1 1 1 1 R1 xR 2 12 x 24 288 3 = + / + OR OR OR ; R R1 R2 12 24 R1 + R 2 12 + 24 36 (Rparallel =) 8.0 () ; (combined resistance = 8.0 + 15 =) 23 () ; 9(c) evidence that reflection must occur at halfway point between eyes and 3 point P / 130 ÷ 2 / 65 ; adjustment for length of mirror / subtraction of 40 ; (x =) 25 (cm) ;

This question in 0653/42 Oct/Nov 2025

7 A student assembles the circuit in Fig. 7.1. 12 V 12.0 Ω A 6.0 Ω Fig. 7.1 The reading on the ammeter is 0.80 A. The potential difference (p.d.) across the 12.0 Ω resistor is 9.6 V. (a) Determine the p.d. across the lamp. p.d. = … V [1] (b) Determine the current in the 6.0 Ω resistor. current = … A [2] (c) Calculate the charge flowing through the lamp in 2.0 minutes. State the unit of charge. charge = … unit … [5] [Total: 8]

8 marks

Mark scheme: 7(a) (12.0 - 9.6 =) 2.4 (V) ; 1 7(b) (I) = V ÷ R or 9.6 ÷ 6.0 ; 2 1.6 (A) ; 7(c) M1 (unit conversion, 2 minutes) = 120 or 2  60 (s) ; 5 M2 (total current = 0.80 + 1.6) = 2.4 ; M3 (Q) = Ix t / 2.4  120 ; M4 290; M5 independent mark: C / coulomb(s) ;

This question in 0653/43 Oct/Nov 2025