Waves in air; fluids; solids

Transcription

1 Waves in air; fluids; solids Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Waves in air; fluids; solids Difficulty Level Bronze Level Booklet Question Paper 1 Time Allowed: 55 minutes Score: /54 Percentage: /100 Page 1

2 Q1.Small water waves are created in a ripple tank by a wooden bar. The wooden bar vibrates up and down hitting the surface of the water. The figure below shows a cross-section of the ripple tank and water. (a) Which letter shows the amplitude of a water wave? Tick one box. J K L (b) The speed of the wooden bar is changed so that the bar hits the water fewer times each second. What happens to the frequency of the waves produced? Tick one box. Increases Does not change Decreases (c) Describe how the wavelength of the water waves in a ripple tank can be measured accurately. Page 2

3 (d) The speed of a wave is calculated using the following equation. wave speed = frequency wavelength The water waves in a ripple tank have a wavelength of 1.2 cm and a frequency of 18.5 Hz. How does the speed of these water waves compare to the typical speed of a person walking? (4) (Total 8 marks) Page 3

4 Q2. (a) A student uses two pieces of equipment, A and B, to display a sound wave. (i) Use words from the box to complete the sentence. a loudspeaker a microphone an oscilloscope a screen A is... and B is.... (ii) Use words from the box to complete the sentence. the amplitude half the amplitude the frequency half the frequency The distance x marked on the diagram measures... of the sound wave. (iii) Complete the sentence. The distance x becomes smaller. This is because the sound has become.... Page 4

5 (b) There is no air in space. Astronauts in space cannot hear sounds from outside their spacesuits. Explain this. (Total 6 marks) Page 5

6 Q3. (a) Infra red radiation can be reflected, absorbed and transmitted by glass. (i) What percentage of infra red is absorbed by the glass?... (ii) Complete the following sentence by drawing a ring around the correct word or phrase. Theabsorbed infra red increases does not change decreases the temperature of the glass. (b) Two of the following statements are true. One of the statements is false. Tick ( ) the boxes next to the two true statements. All objectsabsorb infra red radiation. Blacksurfaces are poor emitters of infra red radiation. A hot objectemits more infra red than a cooler object. Page 6

7 (c) The following statement is false. Blacksurfaces are good reflectors of infra red radiation. Change one word in this statement to make it true. Write down your new statement. (Total 4 marks) Page 7

8 Q4.(a) The diagram shows four sound waves, J, K, L and M, represented on an oscilloscope screen. They are all drawn to the same scale. J K L M (i) Which two of the waves have the same amplitude? Wave... and wave... (ii) Which of the waves would sound the loudest? Wave... (iii) Only one of the waves is an ultrasound wave. Which one is the ultrasound wave? Wave... Give a reason for your answer. (b) The diagram shows ultrasound being used to examine the ligament inside the leg of a horse. Page 8

9 Use words from the box to complete the following sentences. computer detector transmitter The... sends pulses of ultrasound into the leg. When the ultrasound meets the ligament, some is reflected back to the... The reflected pulses are converted by a... into an image that can be seen on the screen. (Total 6 marks) Page 9

10 Q5. Ultrasound waves are very high frequency sound waves. They cannot be heard by humans. (a) Ultrasound waves can be used to clean jewellery. The jewellery is put into a container of cleaning fluid. Complete each sentence to explain how ultrasound can clean jewellery. The ultrasound generator makes the molecules of the cleaning fluid.... The molecules knock particles of... from the surface of the jewellery. (b) Give a medical use for ultrasound.... (c) Ultrasound waves can be represented on the screen of a cathode ray oscilloscope (CRO). The diagrams show three ultrasound waves. Each wave is represented on an identical CRO screen, A, B and C. Page 10

11 Screen A Screen B Screen C (i) How many complete waves are shown on screen B?... (ii) Which screen shows the waves with the highest frequency? Screen... (Total 5 marks) Page 11

12 Q6.(a) The table gives information about the frequencies in the hearing ranges of six different mammals. Name of mammal Bat Dog Dolphin Elephant Human Tiger Frequencies in hearing range 20 Hz 160 khz 20 Hz 30 khz 40 Hz 110 khz 5 Hz 10 khz 20 Hz 20 khz 30 Hz 50 khz (i) Which mammal in the table can hear the highest frequency? (ii) Give one example of a frequency which an elephant can hear but which a tiger cannot hear. Include the unit in your answer. Frequency... (b) A sound wave can be represented as a trace on the screen of an oscilloscope. The diagrams show five traces, A, B, C, D and E, on the oscilloscope. All the traces aredrawn to the same scale. (i) Which three diagrams show traces with the same amplitude? Diagrams...,... and.... Page 12

13 (ii) Which two diagrams show traces with the same frequency? Diagrams... and (c) There is no air in space. Astronauts in space cannot hear sounds from outside their spacesuits. Explain this (Total 6 marks) Page 13

14 Q7.(a) Diagram 1 shows two waves. Diagram 1 (i) Name one wave quantity that is the same for the two waves.... (ii) Name one wave quantity that is different for the two waves.... (iii) The waves in Diagram 1 are transverse. Which one of the following types of wave is not a transverse wave? Draw a ring around the correct answer. gamma rays sound visible light (b) Diagram 2 shows water waves in a ripple tank moving towards and passing through a gap in a barrier. Diagram 2 Page 14

15 Every second, 8 waves pass through the gap in the barrier. The waves have a wavelength of metres. Calculate the speed of the water waves and give the unit. Speed =... (3) (Total 6 marks) Page 15

16 Q8.Figure 1 shows a set of tuning forks. Figure 1 A tuning fork has a handle and two prongs. It is made from metal. When the prongs are struck on a hard object, the tuning fork makes a sound wave with a single frequency. The frequency depends on the length of the prongs. (a) Use the correct answer from the box to complete each sentence. direction loudness pitch speed The frequency of a sound wave determines its.... The amplitude of a sound wave determines its.... (b) Each tuning fork has its frequency engraved on it. A student measured the length of the prongs for each tuning fork. Some of her data is shown in the table. Frequency in hertz Length of prongs in cm (i) Describe the pattern shown in the table. Page 16

17 (ii) Figure 2 shows a full-size drawing of a tuning fork. Figure 2 Measure and record the length of the prongs. Length of prongs =... cm Use the data in the table above to estimate the frequency of the tuning fork in Figure 2. Explain your answer. Estimated frequency =... Hz (3) (c) Ultrasound waves are used in hospitals. (i) Use the correct answer from the box to complete the sentence. electronic hydraulic radioactive Ultrasound waves can be produced by... systems. Page 17

18 (ii) The frequency of an ultrasound wave used in a hospital is Hz. It is not possible to produce ultrasound waves of this frequency using a tuning fork. Explain why. (d) Figure 3 shows a tuning fork and a microphone. The microphone is connected to an oscilloscope. Figure 3 Sciencephotos/Alamy When the tuning fork is struck and then placed in front of the microphone, a trace appears on the oscilloscope screen. Figure 4 shows part of the trace on the screen. Figure 4 Page 18

19 Each horizontal division in Figure 4 represents a time of s. What is the frequency of the tuning fork? Frequency =... Hz (3) (Total 13 marks) Page 19

20 Waves in air; fluids; solids Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Waves in air; fluids; solids Difficulty Level Silver Level Booklet Question Paper 1 Time Allowed: 53 minutes Score: /53 Percentage: /100 Page 1

21 Q1.(a) Explain what ultrasound is (b) Ultrasound is used for pre-natal scanning. This is much safer than using X-rays. However, doctors were only sure ultrasound was safe after experiments on mice. Do you think the ultrasound experiments on mice were justified? Explain your answer (c) Explain what scientists should do if they find evidence that ultrasound may be harmful to human health (Total 6 marks) Q2.A note was played on an electric keyboard. The frequency of the note was 440 Hz. Page 2

22 (a) (i) What does a frequency of 440 Hz mean? (ii) The sound waves produced by the keyboard travel at a speed of 340 m / s. Calculate the wavelength of the note. Give your answer to three significant figures. Wavelength =... metres (3) (b) Figure 1 shows a microphone connected to a cathode ray oscilloscope (CRO) being used to detect the note produced by the keyboard. Figure 1 Figure 2 shows the trace produced by the sound wave on the CRO. Figure 2 Page 3

23 A second note, of different wavelength, was played on the keyboard. Figure 3 shows the trace produced by the sound wave of the second note on the CRO. Figure 3 The settings on the CRO were unchanged. What two conclusions should be made about the second sound wave produced by the keyboard compared with the first sound wave? Give a reason for each conclusion. Conclusion Reason Conclusion Reason (4) (Total 8 marks) Q3.Ultrasound and X-rays are waves used in hospitals to create images of the inside of the Page 4

24 human body. To produce the images below, the waves must enter the human body. Ultrasound scan of an unborn child bone X-ray of a broken Isabelle Limbach/Thinkstock itsmejust/istock (a) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. Describe the features of ultrasound and X-rays, and what happens to each type of wave after it has entered the human body (6) Page 5

25 (b) It would not be safe to use X-rays to produce an image of an unborn child. Explain why (c) Ultrasound can be used for medical treatments as well as for imaging. Give one use of ultrasound for medical treatment (Total 9 marks) Page 6

26 Q4.(a) Light waves transfer energy. (i) Complete the following sentence. The oscillations producing a light wave are... to the direction of the energy transfer by the light wave. (ii) The apparatus in the diagram shows that light waves transfer energy. Describe how switching the desk lamp on and off shows that light waves transfer energy. You do not need to describe the energy transfers. (b) A student holds a wrist watch in front of a plane mirror. The student can see an image of the wrist watch in the mirror. The diagram shows the position of the wrist watch and the mirror. Page 7

27 Draw a ray diagram showing how the image of the wrist watch is formed. Mark the position of the image. (4) (c) The image of the wrist watch seen by the student is virtual. What is a virtual image? (Total 8 marks) Page 8

28 Q5.Waves may be longitudinal or transverse. (a) Describe the differences between longitudinal waves and transverse waves (3) (b) Radio waves are electromagnetic waves. Describe how radio waves are different from sound waves (4) (Total 7 marks) Page 9

29 Q6.(a) Human ears can detect a range of sound frequencies. (i) Use the correct answers from the box to complete the sentence The range of human hearing is from about... Hz to... Hz. (ii) What is ultrasound?.. (iii) Ultrasound can be used to find the speed of blood flow in an artery. State one other medical use of ultrasound.. (b) The speed of an ultrasound wave in soft tissue in the human body is m / s and the frequency of the wave is Hz. Calculate the wavelength of the ultrasound wave Wavelength =... m (c) When ultrasound is used to find the speed of blood flow in an artery: an ultrasound transducer is placed on a person s arm Page 10

30 ultrasound is emitted by the transducer the ultrasound is reflected from blood cells moving away from the transducer the reflected ultrasound is detected at the transducer. Describe the differences between the ultrasound waves emitted by the transducer and the reflected waves detected at the transducer (Total 8 marks) Page 11

31 Q7.(a) What is ultrasound? (b) Figure 1 shows how ultrasound is used to measure the depth of water below a ship. Figure 1 A pulse of ultrasound is sent out from an electronic system on-board the ship. It takes 0.80 seconds for the emitted ultrasound to be received back at the ship. Calculate the depth of the water. Speed of ultrasound in water = 1600 m / s Depth of water =... metres (3) Page 12

32 (c) Ultrasound can be used in medicine for scanning. State one medical use of ultrasound scanning.... (d) Images of the inside of the human body can be made using a Computerised Tomography (CT) scanner. The CT scanner in Figure 2 uses X-rays to produce these images. Figure 2 monkeybusinessimages/istock/thinkstock State one advantage and one disadvantage of using a CT scanner, compared with ultrasound scanning, for forming images of the inside of the human body. Advantage of CT scanning Disadvantage of CT scanning (Total 7 marks) Page 13

33 Waves in air; fluids; solids Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Waves in air; fluids; solids Difficulty Level Gold Level Booklet Question Paper 1 Time Allowed: 31 minutes Score: /31 Percentage: /100 Page 1

34 Q1. (a) The diagram shows a microphone being used to detect the output from a loudspeaker. The oscilloscope trace shows the wave pattern produced by the loudspeaker. (i) How many waves are produced by the loudspeaker in seconds?... (ii) How many waves are produced by the loudspeaker every second? Assume the input to the loudspeaker does not change. (iii) A person with normal hearing cannot hear the sound produced by the loudspeaker. Explain why. Page 2

35 (b) The diagram shows how a very high frequency sound wave can be used to check for internal cracks in a large steel bolt. The oscilloscope trace shows that the bolt does have an internal crack. (i) Explain what happens to produce pulse A and pulse B. (ii) Use the information in the diagram and the equation in the box to calculate the distance from the head of the bolt to the internal crack. distance = speed time Speed of sound through steel = 6000 m/s Show clearly how you work out your answer. Page 3

36 (3) (Total 9 marks) Page 4

37 Q2. (a) The student is using a microphone connected to a cathode ray oscilloscope (CRO). The CRO displays the sound waves as waves on its screen. What does the microphone do? (b) The amplitude, the frequency and the wavelength of a sound wave can each be either increased or decreased. (i) What change, or changes, would make the sound quieter?... (ii) What change, or changes, would make the sound higher in pitch?... (Total 4 marks) Page 5

38 Q3. The picture shows a pre-natal scan obtained using ultrasonic waves. (i) Explain how ultrasonic waves are used to produce the image of an unborn baby. (ii) Give another use for ultrasonic waves. (Total 3 marks) Page 6

39 Q4. Pigs have a layer of fat in their skin. Underneath the fat is a layer of muscle. Ultrasonic waves are used to measure the thickness of the layer of fat. An ultrasound transmitter and detector are attached to the skin of the pig. (a) Explain why ultrasound can be used to measure the thickness of the layer of fat. (b) The oscilloscope does not measure distance directly. (i) What does the oscilloscope measure in this case? (ii) What other information is needed to calculate the thickness of the layer of fat in a pig? (Total 4 marks) Page 7

40 Q5. Ultrasound can be used in industry for detecting internal cracks in metals. (a) State two features of ultrasound (b) The diagram shows an ultrasound transmitter and detector fixed to the front of a metal block. The block has an internal crack. The diagram below shows the screen of the oscilloscope connected to the detector. (i) Explain why pulse A and pulse B occur Page 8

41 (ii) The metal block is 120 mm from front to back. What is the distance, in mm, from the front of the block to the internal crack? Distance =... mm (Total 5 marks) Page 9

42 Q6. (a) The diagrams show oscilloscope traces for the same musical note played on two different instruments. The oscilloscope settings are not changed. (i) How can you tell, from the diagrams, that it is the same musical note? (ii) How can you tell, from the diagrams, that the musical note has been played on different instruments? (b) This passage is from an electronics magazine. Electronic systems can be used to produce ultrasound waves. These waves have a higher frequency than the upper limit for hearing in humans. Ultrasound waves are partially reflected when they meet a boundary between two different media. (i) Approximately what is the highest frequency that humans can hear? Page 10

43 State the number and the unit.... (ii) What does the word media mean when it is used in this passage? (iii) What happens to the ultrasound which reaches the boundary between two different media and is not reflected? (Total 6 marks) Page 11

44 Electromagnetic waves Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Electromagnetic waves Difficulty Level Bronze Level Booklet Question Paper 1 Time Allowed: 58 minutes Score: /58 Percentage: /100 Page 1

45 Q1.The figure below shows an incomplete electromagnetic spectrum. A microwaves B C ultraviolet D gamma (a) What name is given to the group of waves at the position labelled A in the figure above? Tick one box. infrared radio visible light X-ray (b) Electromagnetic waves have many practical uses. Draw one line from each type of electromagnetic wave to its use. Electromagnetic wave Use For fibre optic communications Gamma rays For communicating with a satellite Microwaves Page 2

46 To see security markings Ultraviolet To sterilise surgical instruments (3) (c) Complete the sentence. Use an answer from the box. black body ionising nuclear X-rays can be dangerous to people because X-rays are... radiation. (Total 5 marks) Page 3

47 Q2.(a) The diagram shows the electromagnetic spectrum. The pictures show four devices that use electromagnetic waves. Each device uses a different type of electromagnetic wave. Draw a line from each device to the type of electromagnetic wave that it uses. One has been done for you. (3) (b) A headline from a recent newspaper article is shown below. (i) What serious health problem may be caused by using a sunbed too much? (ii) The pie chart compares the number of deaths in Britain each year which may have been caused by using sunbeds too much, with those which may have been caused by too much exposure to the Sun. Page 4

48 It is difficult for a doctor to be certain that a person has died because of using a sunbed too much. Suggest why. (iii) A spokesperson for a leading cancer charity said: We want people, especially young people, to know the possible dangers of using a sunbed. Why is it important that you know the possible dangers of using a sunbed? (Total 6 marks) Page 5

49 Q3.A lorry has an air horn. The air horn produces sound waves in the air. (a) Use one word to complete the following sentence. Sound waves cause air particles to.... (b) The air horn produces sound waves at a constant frequency of 420 Hz. The wavelength of the sound waves is 0.80 m. Calculate the speed of the sound waves. Speed =... m/s (Total 3 marks) Page 6

50 Q4.Diagram 1 shows four of the seven types of wave in the electromagnetic spectrum. Diagram 1 J K L Visible light Infrared Microwav es Radio waves (a) The four types of electromagnetic wave named in Diagram 1 above are used for communication. (i) Which type of electromagnetic wave is used when a traffic signal communicates with a car driver? (ii) Which type of electromagnetic wave is used to communicate with a satellite in space? (b) Gamma rays are part of the electromagnetic spectrum. Which letter, J, K or L, shows the position of gamma rays in the electromagnetic spectrum? Draw a ring around the correct answer. J K L Page 7

51 (c) Diagram 2 shows an infrared wave. Diagram 2 (i) Which one of the arrows, labelled A, B or C, shows the wavelength of the wave? Write the correct answer, A, B or C, in the box. (ii) Draw a ring around the correct answer to complete the sentence. The wavelength of infrared waves is shorter than the same as longer than the wavelength of radio waves. (d) Mobile phone networks send signals using microwaves. Some people think the energy a person s head absorbs when using a mobile phone may be harmful to health. (i) Scientists have compared the health of people who use mobile phones with the health of people who do not use mobile phones. Page 8

52 Which one of the following statements gives a reason why scientists have done this? Tick ( ) one box. To find out if using a mobile phone is harmful to health. To find out if mobile phones give out radiation. To find out why some people are healthy. (ii) The table gives the specific absorption rate (SAR) value for two different mobile phones. The SAR value is a measure of the maximum energy a person s head absorbs when a mobile phone is used. Mobile Phone SAR value in W/kg X 0.28 Y 1.35 A parent buys mobile phone X for her daughter. Using the information in the table, suggest why buying mobile phone X was the best choice. (Total 8 marks) Page 9

53 Q5.A person can see an image of himself in a tall plane mirror. The diagram shows how the person can see his hat. (a) Which point, A, B or C, shows the position of the image of his hat? Write the correct answer, A, B or C, in the box. (b) On the diagram, use a ruler to draw a light ray to show how the person can see his shoe. (3) (c) Which one of the words in the box is used to describe the image formed by a plane mirror? Draw a ring around the correct answer. imaginary real virtual (Total 5 marks) Page 10

54 Q6.(a) Some humans are short-sighted. Complete the following sentence. Short sight can be caused by the eyeball being too.... (b) Spectacles can be worn to correct short sight. The table below gives information about three different lenses that can be used in spectacles. Lens feature Material Mass in grams Type Lens A Plastic 5.0 Concave (diverging) Lens B Glass 6.0 Convex (converging) Lens C Glass 5.5 Convex (converging) Which lens from Table 2 would be used to correct short sight? Draw a ring around the correct answer. Lens A Lens B Lens C Give the reason for your answer (c) Every lens has a focal length. Which factor affects the focal length of a lens? Tick ( ) one box. The colour of the lens The refractive index of the lens material Page 11

55 The size of the object being viewed (d) A lens has a focal length of 0.25 metres. Calculate the power of the lens Power of lens =... dioptres (e) Laser eye surgery can correct some types of eye defect. Which of the following is another medical use for a laser? Tick ( ) one box. Cauterising open blood vessels Detecting broken bones Imaging the lungs (f) The figure shows a convex lens being used as a magnifying glass. Page 12

56 An object of height 14 mm is viewed through a magnifying glass. The image height is 70 mm. Calculate the magnification produced by the lens in the magnifying glass Magnification =... (Total 9 marks) Page 13

57 Q7.The figure below shows an X-ray image of a human skull. Stockdevil/iStock/Thinkstock (a) Use the correct answers from the box to complete the sentence. absorbs ionises reflects transmits When X-rays enter the human body, soft tissue... X-rays and bone... X-rays. (b) Complete the following sentence. The X-rays affect photographic film in the same way that... does. (c) The table below shows the total dose of X-rays received by the human body when different parts are X-rayed. Part of body X-rayed Dose of X-rays received by human body in arbitrary units Head 3 Page 14

58 Chest 4 Pelvis 60 Calculate the number of head X-rays that are equal in dose to one pelvis X-ray Number of head X-rays =... (d) Which one of the following is another use of X-rays? Tick ( ) one box. Cleaning stained teeth Killing cancer cells Scanning of unborn babies (Total 6 marks) Page 15

59 Q8.Light changes direction as it passes from one medium to another. (a) Use the correct answer from the box to complete the sentence. diffraction reflection refraction The change of direction when light passes from one medium to another is called.... (b) Draw a ring around the correct answer to complete the sentence. When light passes from air into a glass block, it changes away from the normal. direction towards the normal. to always travel along the normal. (c) Diagram 1 shows light rays entering and passing through a lens. Diagram 1 (i) Which type of lens is shown in Diagram 1? Draw a ring around the correct answer. concave convex diverging Page 16

60 (ii) In Diagram 1, what is the point X called?. (d) A lens acts like a number of prisms. Diagram 2 shows two parallel rays of light entering and passing through prism A and prism C. Diagram 2 Draw a third parallel ray entering and passing through prism B. (4) (e) What two factors determine the focal length of a lens? (Total 10 marks) Page 17

61 Q9.(a) The visible light spectrum has a range of frequencies. Figure 1 shows that the frequency increases from red light to violet light. Figure 1 Increasing frequency Red Green Violet Use the correct answers from the box to complete the sentence. decreases stays the same increases As the frequency of the light waves increases, the wavelength of the light waves... and the energy of the light waves.... (b) Bottled beer will spoil if the intensity of the light passing through the glass bottle into the beer is too high. Figure 3 shows the intensity of the light that is transmitted through three different pieces of glass. Figure 3 Page 18

62 Wavelength 10 9 in metres (i) The pieces of glass all had the same thickness. Suggest why. (ii) Bottles made of brown glass are suitable for storing beer. Suggest why. (Total 4 marks) Page 19

63 Electromagnetic waves Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Electromagnetic waves Difficulty Level Silver Level Booklet Question Paper 1 Time Allowed: 54 minutes Score: /53 Percentage: /100 Page 1

64 Q1.Lenses can be used to correct visual defects. Figure 1 shows a child wearing glasses. Wearing glasses allows a lens to correct a visual defect. Figure 1 monkeybusinessimages/istock/thinkstock (a) Figure 2 shows rays of light entering a child s eye and being focused at a point. This point is not on the retina so the child sees a blurred image. Figure 2 (i) What is the visual defect of this eye? (ii) Use the correct answer from the box to complete the sentence. Page 2

65 converging convex diverging The type of lens used to correct this visual defect is a... lens. (b) Visual defects may be corrected with eye surgery. A laser may be used in eye surgery. Use the correct answer from the box to complete the sentence. light sound X-rays A laser is a concentrated source of.... (c) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. Lasers can be used to correct a visual defect by changing the shape of the cornea. A knife is used to cut a flap in the cornea. The laser vaporises a portion of the cornea and permanently changes its shape. The flap is then replaced. Most patients are back at work within a week. Driving may be unsafe for one to two weeks. Tinted glasses with ultraviolet protection are needed when out in the sun for the first three months. Many people in their mid-40s need reading glasses. This is because the eye lens becomes less flexible with age. Laser surgery cannot cure this. Laser surgery for both eyes costs A pair of glasses costs 250. Describe the advantages and disadvantages of: having laser surgery to correct visual defects wearing glasses to correct visual defects.... Page 3

66 Extra space (6) (d) Figure 3 shows parallel rays of light, from a point on a distant object, entering a camera. Figure 3 Describe the adjustment that has to be made to focus the image on the film.... Page 4

67 (Total 11 marks) Q2.(a) What is ultrasound? Page 5

68 (b) Figure 1 shows how ultrasound is used to measure the depth of water below a ship. Figure 1 A pulse of ultrasound is sent out from an electronic system on-board the ship. It takes 0.80 seconds for the emitted ultrasound to be received back at the ship. Calculate the depth of the water. Speed of ultrasound in water = 1600 m / s Depth of water =... metres (3) (c) Ultrasound can be used in medicine for scanning. Page 6

69 State one medical use of ultrasound scanning.... (d) Images of the inside of the human body can be made using a Computerised Tomography (CT) scanner. The CT scanner in Figure 2 uses X-rays to produce these images. Figure 2 monkeybusinessimages/istock/thinkstock State one advantage and one disadvantage of using a CT scanner, compared with ultrasound scanning, for forming images of the inside of the human body. Advantage of CT scanning Disadvantage of CT scanning (Total 7 marks) Q3.A teacher demonstrates the production of circular waves in a ripple tank. Page 7

70 Diagram 1 shows the waves at an instant in time. Diagram 1 (a) Show on Diagram 1 the wavelength of the waves. (b) The teacher moves the source of the waves across the ripple tank. Diagram 2 shows the waves at an instant in time. Diagram 2 (Actual size) Page 8

71 (i) Use the correct answer from the box to complete each sentence. decreased increased stayed the same In Diagram 2, the observed wavelength of the waves at X has.... In Diagram 2, the frequency of the waves at X has.... (ii) Take measurements from Diagram 2 to determine the wavelength of the waves received at X. Give the unit... Wavelength =... (3) (c) The teacher uses the waves in the ripple tank to model the changes in the wavelengths of light observed from distant galaxies. When observed from the Earth, there is an increase in the wavelength of light from distant galaxies. (i) State the name of this effect.. (ii) What does this increase in wavelength tell us about the movement of most galaxies? Page 9

72 .. (iii) Explain how this observation supports the Big Bang theory of the formation of the Universe (4) (iv) State one other piece of evidence that supports the Big Bang theory of the formation of the Universe... (Total 13 marks) Q4.The data given in the table below was obtained from an investigation into the refraction of Page 10

73 light at an air to glass boundary. Angle of incidence Angle of refraction Describe an investigation a student could complete in order to obtain similar data to that given in the table above. Your answer should consider any cause of inaccuracy in the data. A labelled diagram may be drawn as part of your answer. (Total 6 marks) Page 11

74 Q5.The data given in the table below was obtained from an investigation into the refraction of light at an air to glass boundary. Angle of incidence Angle of refraction (a) Describe an investigation a student could complete in order to obtain similar data to that given in the table above. Your answer should consider any cause of inaccuracy in the data. A labelled diagram may be drawn as part of your answer. (6) (b) State the reason why light is refracted as it crosses from air into glass. (Total 7 marks) Page 12

75 Q6.A student investigated how the magnification produced by a convex lens varies with the distance (d) between the object and the lens. The student used the apparatus shown in Figure 1. Figure 1 (a) The student measured the magnification produced by the lens by measuring the image height in centimetres. Explain why the image height in centimetres was the same as the magnification. (b) The data recorded by the student is given in Table 1. Table 1 Distance between the object and the lens in cm Magnification It would be difficult to obtain accurate magnification values for distances greater than 60 cm. Page 13

76 Suggest one change that could be made so that accurate magnification values could be obtained for distances greater than 60 cm. (c) The graph in Figure 2 is incomplete. Figure 2 Complete the graph in Figure 2 by plotting the missing data and then drawing a line of best fit. (d) How many times bigger is the image when the object is 35 cm from the lens compared to when the object is 55 cm from the lens? Page 14

77 (e) During the investigation the student also measured the distance between the lens and the image. Table 2 gives both of the distances measured and the magnification. Distance between the lens and the image in cm Table 2 Distance between the lens and the object in cm Magnification Consider the data in Table 2. Give a second way that the student could have determined the magnification of the object. Justify your answer with a calculation. (Total 9 marks) Page 15

78 Electromagnetic waves Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Electromagnetic waves Difficulty Level Gold Level Booklet Question Paper 1 Time Allowed: 59 minutes Score: /59 Percentage: /100 Page 1

79 Q1. Radio waves and microwaves are two types of electromagnetic wave. Both waves: can be used for communications travel at the same speed through air. (a) Give two more properties that are the same for both radio waves and microwaves (b) Some satellites are used to transmit television programmes. Signals are sent to, and transmitted from, the satellites using microwaves. What is the property of microwaves that allows them to be used for satellite communications? (c) Electromagnetic waves travel at a speed of m/s. A radio station transmits waves with a wavelength of m. Calculate the frequency of the radio waves. Show clearly how you work out your answer and give the unit Frequency =... (3) (Total 6 marks) Page 2

80 Q2.Galaxies emit all types of electromagnetic wave. (a) (i) Which type of electromagnetic wave has the shortest wavelength? (ii) State one difference between an ultraviolet wave and a visible light wave. (b) Electromagnetic waves travel through space at a speed of 3.0 x 10 8 m/s. The radio waves emitted from a distant galaxy have a wavelength of 25 metres. Calculate the frequency of the radio waves emitted from the galaxy and give the unit Frequency =... (3) (c) Scientists use a radio telescope to measure the wavelength of the radio waves emitted from the galaxy in part (b) as the waves reach the Earth. The scientists measure the wavelength as 25.2 metres. The effect causing this observed increase in wavelength is called red-shift. (i) The waves emitted from most galaxies show red-shift. What does red-shift tell scientists about the direction most galaxies are moving? Page 3

81 (ii) The size of the red-shift is not the same for all galaxies. What information can scientists find out about a galaxy when they measure the size of the red-shift the galaxy produces? (iii) What does the observation of red-shift suggest is happening to the Universe? (Total 9 marks) Page 4

82 Q3. (a) The diagram shows a converging lens being used as a magnifying glass. (i) On the diagram, use a ruler to draw two rays from the top of the object which show how and where the image is formed. Represent the image by an arrow drawn at the correct position. (3) (ii) Use the equation in the box to calculate the magnification produced by the lens. Show clearly how you work out your answer. Magnification =... Page 5

83 (b) A camera also uses a converging lens to form an image. Describe how the image formed by the lens in a camera is different from the image formed by a lens used as a magnifying glass (Total 7 marks) Page 6

84 Q4.The diagram shows the apparatus that a student used to investigate the heating effect of different wavelengths of light. (a) (i) The student put thermometer D outside of the light spectrum. Suggest why (ii) The table gives the position and reading of each thermometer 10 minutes after the investigation started. Thermometer Position of thermometer Temperature in C A in violet light 21 B in green light 22 C in red light 24 D outside the spectrum 20 What should the student conclude from the data in the table? Page 7

85 (b) A similar investigation completed in 1800 by the scientist Sir William Herschel led to the discovery of infrared radiation. Suggest how the student could show that the spectrum produced by the glass prism has an infrared region (c) A person emits infrared radiation at a frequency of 3.2 x Hz. Calculate the wavelength of the infrared radiation that a person emits. Take the speed of infrared radiation to be 3.0 x 10 8 m/s. Show clearly how you work out your answer Wavelength =... m (d) A thermal imaging camera detects infrared radiation. Electronic circuits inside the camera produce a visible image of the object emitting the infrared radiation. At night, police officers use thermal imaging cameras to track criminals running away from crime scenes. Thermal imaging cameras work better at night than during the day. Page 8

86 Explain why (Total 9 marks) Page 9

87 Q5.Different parts of the electromagnetic spectrum have different uses. (a) The diagram shows the electromagnetic spectrum. Radio waves Microwaves Infrared Visible light Ultraviolet X-rays Gamma rays (i) Use the correct answers from the box to complete the sentence. amplitude frequency speed wavelength The arrow in the diagram is in the direction of increasing... and decreasing.... (ii) Draw a ring around the correct answer to complete the sentence. The range of wavelengths for waves in the electromagnetic to 10 4 spectrum is approximately 10-4 to to metres. (b) The wavelength of a radio wave is 1500 m. The speed of radio waves is m / s. Calculate the frequency of the radio wave. Give the unit Page 10

88 Frequency =... (3) (c) (i) State one hazard of exposure to infrared radiation.. (ii) State one hazard of exposure to ultraviolet radiation.. (d) X-rays are used in hospitals for computed tomography (CT) scans. (i) State one other medical use for X-rays... (ii) State a property of X-rays that makes them suitable for your answer in part (d)(i)... (iii) The scientific unit of measurement used to measure the dose received from radiations, such as X-rays or background radiation, is the millisievert (msv). The table shows the X-ray dose resulting from CT scans of various parts of the body. The table also shows the time it would take to get the same dose from background radiation. Page 11

89 Part of the body X-ray dose in msv Time it would take to get the same dose from background radiation Abdomen years Sinuses months Spine months A student suggests that the X-ray dose and the time it would take to get the same dose from background radiation are directly proportional. Use calculations to test this suggestion and state your conclusion (3) (Total 13 marks) Page 12

90 Q6.(a) The wavelengths of four different types of electromagnetic wave, including visible light waves, are given in the table. Type of wave Visible light A B C Wavelength mm 1.1 km 100 mm 0.18 mm Which of the waves, A, B, or C, is an infra red wave?... (b) A TV station broadcasts at khz. The waves travel through the air at m/s. Calculate the wavelength of the waves broadcast by this station. Show clearly how you work out your answer Wavelength =... m (c) What happens when a metal aerial absorbs radio waves? (d) Stars emit all types of electromagnetic waves. Telescopes that monitor X-rays are Page 13

91 mounted on satellites in space. Why would an X-ray telescope based on Earth not be able to detect X-rays emitted from distant stars? (Total 6 marks) Page 14

92 Q7.Different wavelengths of light can be used to transmit information along optical fibres. The graph below shows how the percentage of incident light transmitted through a fibre varies with the wavelength of light and the length of the fibre. Wavelength 10 7 metres Compare the percentages of incident light transmitted through the two different fibres over the range of wavelengths shown (Total 3 marks) Page 15

93 Q8.(a) Electromagnetic waves form a continuous spectrum with a range of wavelengths. What is the approximate range of wavelengths of electromagnetic waves? Tick ( ) one box metres to 10 4 metres 10 4 metres to metres 10 6 metres to 10 6 metres (b) Infrared waves and microwaves are used for communications. (i) Give one example of infrared waves being used for communication. (ii) A mobile phone network uses microwaves to transmit signals through the air. The microwaves have a frequency of Hz and travel at a speed of m/s. Calculate the wavelength of the microwaves. Give your answer to two significant figures. Wavelength =... m (3) Page 16

94 (c) Some scientists suggest there is a possible link between using a mobile phone and male fertility. The results of their study are given in the table. Mobile phone use in hours per day Sperm count in millions of sperm cells per cm 3 of semen 0 86 less than more than 4 50 The results show a negative correlation: the more hours a mobile phone is used each day, the lower the sperm count. However, the results do not necessarily mean using a mobile phone causes the reduced sperm count. Suggest one reason why (Total 6 marks) Page 17

95 Black Body Radiation Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Black Body Radiation Difficulty Level Bronze Level Booklet Question Paper 1 Time Allowed: 34 minutes Score: /34 Percentage: /100 Page 1

96 Q1. (a) Infra red radiation can be reflected, absorbed and transmitted by glass. (i) What percentage of infra red is absorbed by the glass?... (ii) Complete the following sentence by drawing a ring around the correct word or phrase. Theabsorbed infra red increases does not change decreases the temperature of the glass. (b) Two of the following statements are true. One of the statements is false. Tick ( ) the boxes next to the two true statements. All objectsabsorb infra red radiation. Blacksurfaces are poor emitters of infra red radiation. A hot objectemits more infra red than a cooler object. Page 2

97 (c) The following statement is false. Blacksurfaces are good reflectors of infra red radiation. Change one word in this statement to make it true. Write down your new statement. (Total 4 marks) Page 3

98 Q2.The diagram shows the design of a solar cooker. The cooker heats water using infrared radiation from the Sun. (a) Why is the inside of the large curved dish covered with shiny metal foil? (b) Which would be the best colour to paint the outside of the metal cooking pot? Draw a ring around the correct answer. black silver white Give a reason for your answer Page 4

99 (c) Why does the cooking pot have a lid? (d) Calculate how much energy is needed to increase the temperature of 2 kg of water by 80 C. The specific heat capacity of water = 4200 J/kg C Energy =... J (Total 6 marks) Page 5

100 Q3. A student did two experiments on radiation. The apparatus he used is shown in the diagram. Experiment 1 The student put the same volume of cold water into the two cans. He then switched on the heater. Ten minutes later the water in the can with the dull black surface was much hotter than the water in the other can. Experiment 2 The student filled both cans with boiling water. This time he left the heater off. Ten minutes later the water in the can with the dull black surface was much cooler than the water in the other can. Use words from the box to complete the sentences. absorber conductor emitter reflector Page 6

101 Experiment 1 shows that the dull black surface is a good... of radiation and that the shiny silver surface is a good... of radiation. Experiment 2 shows that the dull black surface is a good... of radiation. (Total 3 marks) Page 7

102 Q4. The diagram shows the equipment a student used to investigate how the colour of a surface affects how fast it emits (gives out) heat. An equal volume of boiling water was poured into each metal can. The student then recorded the temperature of the water in each can every minute for ten minutes. (a) (i) Which of the following was a control variable in this investigation? Put a tick ( ) in the box next to your answer. The volume of boiling water. The decrease in temperature of the water. The outside colour of the metal can. (ii) Give one advantage of using a temperature sensor and datalogger rather than a thermometer to measure the temperature of the water. Page 8

103 (b) The student s results for both cans are plotted on the graph. Which line, A or B, shows how the temperature of the water inside the black-coloured metal can changed? Draw a ring around your answer. A B Explain the reason for your answer (c) Some gardeners make soil darker by digging black soot into the soil. Other gardeners use straw to protect plants from the cold. (i) Complete the following sentence by drawing a ring around the correct line in the box. On a warm day, the temperature of darker coloured soil will increase slower than as fast as the temperature of lighter coloured soil. faster than Page 9

104 (ii) Give a reason for your answer to part (c)(i). (iii) The statement in the box is false. Straw keeps plants warm by trapping air. This is because air is a good conductor. Change one word in the statement to make the statement true. Write down your new statement. The answer has been started for you. This is because air is a... (Total 7 marks) Page 10

105 Q5. (a) The graph compares how quickly hot water cooled down in two glass beakers with different surface areas. The volume of water in each beaker was the same. Describe how the surface area of the water affected how fast the water cooled down. (b) Some foxes live in a hot desert environment. This type of fox has very large ears. Explain how the size of the fox s ears help it to keep cool in a hot desert. Page 11

106 (c) Polar bears and reindeer are adapted to live in cold environments. Use the words in the box to complete the following sentences. conduction convection radiation (i) The white colour of a polar bear s fur helps to keep the polar bear warm by reducing the heat lost by.... (ii) The hairs of a reindeer are hollow. The air trapped inside the hairs reduces the heat lost by.... (Total 5 marks) Page 12

107 Q6. (a) Use the words from the box to complete the following sentences. conduction convection radiation (i) The transfer of thermal energy (heat) by the movement of hot liquids is called.... (ii) The transfer of thermal energy (heat) from one particle to another is called.... (b) A student set up the following equipment. The 3 metal plates are the same distance from the heater. The surfaces of each of the 3 metal plates are different colours. The student switched the heater on for 10 minutes. The thermometers were read before the heater was switched on. The thermometers were read again just after the heaters were switched off. The readings are shown in the table. Temperature before switching on in C Temperature after switching on in C Page 13

108 (i) Which set of readings, 1, 2 or 3, is most likely to have been taken from the thermometer labelled L?... Give a reason for your answer. (ii) Which one of the following was not a control variable in this experiment? Put a tick ( ) in the box next to your answer. the distance between the heater and the metal plates the power of the heater the temperature before the heater was switched on the colour of the metal plates (iii) Suggest one advantage of using a temperature sensor, data logger and computer, rather than a thermometer to carry out this experiment. Page 14

109 (c) The picture shows a fire fighter putting out a forest fire. The fire fighter s clothing has thick thermal padding inside and a light coloured, fire proof, shiny layer outside. (i) What is the main way that heat is transferred through the air from the fire to the fire fighter? (ii) Why is the outside layer of the clothing shiny? (d) The graph shows the result of a laboratory test on two types of thermal padding. Each type of padding was put onto a very hot metal surface and the temperature inside the padding was taken every minute. Page 15

110 Which type of padding, M or N, would it be best to use inside the fire fighter s clothing? Give a reason for your answer (Total 9 marks) Page 16

111 Black body radiation Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Black body radiation Difficulty Level Silver Level Booklet Question Paper 1 Time Allowed: 48 minutes Score: /48 Percentage: /100 Page 1

112 Q1. A wood burning stove is used to heat a room. Photograph supplied by istockphoto/thinkstock The fire in the stove uses wood as a fuel. The fire heats the matt black metal case of the stove. (a) The air next to the stove is warmed by infrared radiation. How does the design of the stove help to improve the rate of energy transfer by infrared radiation? (b) Burning 1 kg of wood transfers 15 MJ of energy to the stove. The stove then transfers 13.5 MJ of energy to the room. Page 2

113 Calculate the efficiency of the stove. Show clearly how you work out your answer Efficiency =... (c) Some of the energy from the burning wood is wasted as the hot gases leave the chimney and warm the air outside the house. Name one other way energy is wasted by the stove.... (d) Some people heat their homes using electric heaters. Other people heat their homes using a wood burning stove. Give two environmental advantages of using a wood burning stove to heat a home rather than heaters that use electricity generated from fossil fuels (e) The metal case of the stove gets hot when the fire is lit. Here is some information about the stove. Mass of metal case 100 kg Starting temperature of metal case 20 C Final temperature of metal case 70 C Page 3

114 Specific heat capacity of metal case 510 J/kg C Calculate the energy required to raise the temperature of the metal case to 70 C. Show clearly how you work out your answer and give the unit Energy required =... (3) (Total 10 marks) Page 4

115 Q2.The diagram shows a simple type of portable shower. The water container is a strong plastic bag that is black on one side and white on the other. To warm the water, the bag is placed on the ground in direct sunlight, with the black side facing the Sun. (a) (i) Name the process by which heat is transferred from the Sun to the outside of the bag. (ii) Explain why the black side of the bag and not the white side should face the Sun. (b) The graph shows how the temperature of the water inside a full bag increases after the bag is placed outside on a sunny day. Page 5

116 (i) How long does it take for the water to reach 37 C?... (ii) Describe how the temperature of the water changes during the three hours. (c) A different manufacturer makes the same type of portable shower but uses a bag with a larger surface area. The bag is made from the same coloured plastics and holds the same amount of water. (i) To compare the efficiency of the two bags at heating water, several variables need to be controlled. Name two variables that need to be controlled Page 6

117 (ii) The second bag has a larger surface area. Draw a line on the graph to show how the temperature of the water inside the second bag would change over the first hour. Assume that the two bags are tested in exactly the same way. (Total 8 marks) Page 7

118 Q3.All objects emit and absorb infrared radiation. (a) Use the correct answer from the box to complete each sentence. dark matt dark shiny light matt light shiny The best emitters of infrared radiation have... surfaces. The worst emitters of infrared radiation have... surfaces. (b) Diagram 1 shows a sphere which is at a much higher temperature than its surroundings. Diagram 1 Energy is transferred from the sphere to the surroundings. The table shows readings for the sphere in three different conditions, A, B and C. Condition Temperature of sphere in C Temperature of surroundings in C A 70 5 B 80 0 C Page 8

119 In each of the conditions, A, B and C, the sphere transfers energy to the surroundings at a different rate. Put conditions A, B and C in the correct order. Give a reason for your answer (c) Diagram 2 shows a can containing water. A student investigates how quickly a can of water heats up when it is cooler than room temperature. Diagram 2 The student has four cans, each made of the same material, with the following outer surfaces. Page 9

120 dark matt dark shiny light matt light shiny The student times how long it takes the water in each can to reach room temperature. Each can contains the same mass of water at the same starting temperature. (i) Which can of water will reach room temperature the quickest? Give a reason for your answer..... (ii) Apart from material of the can, mass of water and starting temperature, suggest three control variables for the student s investigation (3) (d) The photographs show two different foxes. Fox A Fox B Page 10

121 By Algkalv (Own work) [CC-BY-3.0], via Wikimedia Commons EcoPic/iStock Which fox is better adapted to survive cold conditions? Give reasons for your answer (3) (Total 12 marks) Page 11

122 Q4.(a) A company is developing a system which can heat up and melt ice on roads in the winter. This system is called energy storage. During the summer, the black surface of the road will heat up in the sunshine. This energy will be stored in a large amount of soil deep under the road surface. Pipes will run through the soil. In winter, cold water entering the pipes will be warmed and brought to the surface to melt ice. The system could work well because the road surface is black. Suggest why (b) (i) What is meant by specific latent heat of fusion? (ii) Calculate the amount of energy required to melt 15 kg of ice at 0 C. Specific latent heat of fusion of ice = J/kg. Energy =... J (c) Another way to keep roads clear of ice is to spread salt on them. When salt is added to ice, the melting point of the ice changes. A student investigated how the melting point of ice varies with the mass of salt added. The figure below shows the equipment that she used. Page 12

123 The student added salt to crushed ice and measured the temperature at which the ice melted. (i) State one variable that the student should have controlled. (ii) During the investigation the student stirred the crushed ice. Suggest two reasons why. Tick ( ) two boxes. Tick ( ) To raise the melting point of the ice To lower the melting point of the ice To distribute the salt throughout the ice To keep all the ice at the same temperature To reduce energy transfer from the surroundings to the ice Page 13

124 (iii) The table below shows the data that the student obtained. Mass of salt added in grams Melting point of ice in C Describe the pattern shown in the table. (d) Undersoil electrical heating systems are used in greenhouses. This system could also be used under a road. A cable just below the ground carries an electric current. One greenhouse system has a power output of 0.50 kw. Calculate the energy transferred in 2 minutes Energy transferred =... J (3) (e) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. A local council wants to keep a particular section of a road clear of ice in the winter. Describe the advantages and disadvantages of keeping the road clear of ice using: energy storage salt undersoil electrical heating Page 14

125 Extra space (6) (Total 18 marks) Page 15

126 Q5.Figure 1 shows one way that biscuit manufacturers cook large quantities of biscuits. The uncooked biscuits are placed on a moving metal grid. The biscuits pass between two hot electrical heating elements inside an oven. The biscuits turn brown as they cook. Figure 1 The oven has two control knobs, as shown in Figure 2. Figure 2 Power Speed of moving metal grid watts Slow Fast (a) Which type of electromagnetic radiation makes the biscuits turn brown?... (b) Suggest two ways of cooking the biscuits in this oven, to make them turn browner Page 16

127 (c) The inside and outside surfaces of the oven are light-coloured and shiny. Explain why (3) (Total 6 marks) Page 17

128 Black body Radiation Question Paper 1 Level GCSE (9-1) Subject Physics Exam Board AQA Topic 4.6 Waves Sub-Topic Black body Radiation Difficulty Level Gold Level Booklet Question Paper 1 Time Allowed: 29 minutes Score: /29 Percentage: /100 Page 1

129 Q1.The diagram shows the apparatus that a student used to investigate the heating effect of different wavelengths of light. (a) (i) The student put thermometer D outside of the light spectrum. Suggest why (ii) The table gives the position and reading of each thermometer 10 minutes after the investigation started. Thermometer Position of thermometer Temperature in C A in violet light 21 B in green light 22 C in red light 24 D outside the spectrum 20 What should the student conclude from the data in the table? Page 2

130 (b) A similar investigation completed in 1800 by the scientist Sir William Herschel led to the discovery of infrared radiation. Suggest how the student could show that the spectrum produced by the glass prism has an infrared region (c) A person emits infrared radiation at a frequency of 3.2 x Hz. Calculate the wavelength of the infrared radiation that a person emits. Take the speed of infrared radiation to be 3.0 x 10 8 m/s. Show clearly how you work out your answer Wavelength =... m (d) A thermal imaging camera detects infrared radiation. Electronic circuits inside the camera produce a visible image of the object emitting the infrared radiation. At night, police officers use thermal imaging cameras to track criminals running away from crime scenes. Thermal imaging cameras work better at night than during the day. Page 3

131 Explain why (Total 9 marks) Page 4

132 Q2. The diagram comes from a leaflet about a coal effect gas fire. It shows how air circulates through the fire. (a) Explain in detail why the air travels from C to A. (4) (b) The black fuel effect lumps become very hot. (i) Name the process by which the lumps transfer thermal energy to the room as shown at B.... (ii) Suggest one feature of the black fuel effect lumps which make them efficient at transferring energy. Page 5

133 (Total 6 marks) Page 6

134 Q3. The drawing shows water being heated in a metal saucepan. (a) Explain, in terms of the particles in the metal, how heat energy is transferred through the base of the saucepan. (b) Energy is transferred through the water by convection currents. Explain what happens to cause a convection current in the water. The answer has been started for you. As heat energy is transferred through the saucepan, the water particles at the bottom Page 7

135 (3) (c) Some energy is transferred from the hotplate to the air by thermal radiation. What is meant by thermal radiation? (Total 6 marks) Page 8

136 Q4. The diagram shows a fridge-freezer. (a) By which method is heat transferred through the walls of the fridge-freezer? (b) The inside of the fridge is at 4 C. The inside of the freezer is at 18 C. Into which part of the fridge-freezer will the rate of heat transfer be greater? Draw a ring around your answer. the fridge the freezer Give a reason for your answer. (c) The outside surface of the fridge-freezer is white and shiny. Give two reasons why this type of surface is suitable for a fridge-freezer. Page 9

137 1. 2. (Total 4 marks) Page 10

138 Q5. A student investigated the effect of shape and colour on heat transfer. The student used metal containers with the same volume but with different shapes and outside colour. The containers were each filled with water at 100 C. After 20 minutes the temperature of the water inside each container was measured. B A C D The results from the investigation are given in the table. Container Colour Temperature after 20 minutes in C Temperature fall in C A White B Black C White D Black (i) The student uses the results in the table to see if shape has affected heat transfer. Which containers should the student compare to do this? Give a reason for your answer. Page 11