Paper - The Polesworth School
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Q1. The pie charts show the relative proportions of electricity generated in Japan from different energy sources in 1975 and 2005. (a) Describe and suggest a reason for two differences in the energy sources used in 2005 compared with 1975. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (b) Mining for coal often releases large amounts of methane gas. Methane is both explosive and a greenhouse gas. At the Sihe coal mine in China the methane is diverted to a gas burning power station where it is used to generate electricity. (i) A newspaper reported a scientist as saying: If the concentration of greenhouse gases in the atmosphere doubles, the average temperature of the Earth will increase by up to 5 °C over the next 100 years. What has been stated in the newspaper? Draw a ring a round your answer. a fact prediction a guess a Give a reason for your answer. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. (2) (ii) Explain an environmental advantage of taking the methane gas from coal mines and using it to generate electricity. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. (2) (c) The average person in Britain uses 1930 kWh of electricity each year. Many people in the world’s poorest countries do not have access to electricity. Giving examples, explain why electricity is essential for both improving public health and for modern communications. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (3) (Total 9 marks) Q2. Water waves can be made by vibrating a wooden bar up and down in a tray of water. The bar moves up and down at a frequency of 5 hertz. (a) Calculate the speed, in cm/s, of the water waves. Write down the equation you use and then show clearly how you work out your answer. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ Wave speed = ................................... cm/s (3) (b) The graph shows how the speed of deep ocean waves depends on the wavelength of the waves. Use the graph to predict a speed for waves with a wavelength of 140 m. Show clearly how you have used the graph to work out your answer. Speed of waves = .................................. m/s (2) (Total 5 marks) Q3. The diagram shows a plane mirror used by a dentist to see the back of a patient’s tooth. (a) Use a ruler to draw a ray of light on the diagram to show how the dentist is able to see the tooth labelled Z. (3) (b) Describe the image formed by a plane mirror. ............................................................................................................ ............ ............................................................................................................ ............ (2) (Total 5 marks) Q4. The picture shows one type of solar water heater. Water from the tank is slowly pumped through copper pipes inside the solar panel where the water is heated by energy from the Sun. (a) Explain why the copper pipes inside the solar panel are painted black. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (b) Each day the average European family uses 100 kg of hot water. To kill bacteria, the water going into the tank at 20 °C must be heated to 60 °C. Calculate the energy needed to increase the temperature of 100 kg of water by 40 °C. Specific heat capacity of water = 4200 J/kg °C. Write down the equation you use, and then show clearly how you work out your answer. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ Energy transferred = .................................... J (2) (c) The bar chart shows how the amount of solar energy transferred to the water heater varies throughout the year. How many months each year will there not be enough solar energy to provide the hot water used by an average European family? .................................................. months (1) (d) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. The water in the tank could be heated by using an electric immersion heater. Outline the advantages and disadvantages of using solar energy to heat the water rather than using an electric immersion heater. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (6) (Total 11 marks) Q5. (a) Scientific research carried out in 13 countries has tried to find out if there are any links between using a mobile phone and developing different types of cancer. About 13 000 people, half with cancer and half in good health, were interviewed about their mobile phone use. (i) Suggest why people in good health were interviewed. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. (1) (ii) Interviewing 13 000 people gave the researchers a large sample size. Give one advantage, in any research project, of having a large sample size rather than a small sample size. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. (1) (b) The following information was included in a newspaper article about the research project. • It may be difficult to prove there is a link simply by asking people how much they use a mobile phone. People’s memories are not always accurate. • Scientists in Israel found that people who use a mobile phone a lot are 50% more likely to develop a cancer on the salivary gland just in front of the ears. • The cost of the research, £20 million, has been partly paid for by mobile phone companies. • No children were included in the research. (i) Draw a ring around the correct answer to complete the following sentence. environmental Using children in scientific research raises ethical issues. social (1) (ii) Suggest two reasons why some people are concerned that the research was partly paid for by mobile phone companies. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. (2) (iii) In Germany, mobile phones that emit very low levels of radiation are marked with a special symbol. Explain why low emission mobile phones should be marked in this way. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. .................................................................................................. ............. (2) (Total 7 marks) Q6. The bar charts show the rate of energy loss from the body of a runner at the start of a marathon race and half way through the race. (a) It is important that the energy loss by evaporation increases during the race. Explain why. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (b) At the end of the marathon the runner covers herself in a silvered space blanket. Explain how the space blanket helps keep the runner warm. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (Total 4 marks) Q7. The diagrams show the cross-section of three double glazed windows. The gap between the two sheets of glass can be filled with either air or a mixture of air and argon. The U-values for different types of double glazed windows, using different types of glass X and Y, are given in the table. Type of window (a) 12 mm gap 16 mm gap 20 mm gap 1 Glass type X with air 2.9 2.7 2.8 2 Glass type X with air and argon 2.7 2.6 2.6 3 Glass type Y with air 1.9 1.8 1.8 4 Glass type Y with air and argon 1.6 1.5 1.5 Which type of window, 1, 2, 3 or 4 is the least energy efficient? ............................................................................................................ ............ (1) (b) Which two windows should be compared to decide if adding argon to the gap improves the energy efficiency of the window? ............................................................................................................ ............ (1) (c) A householder is going to buy new windows. The sales assistant recommends that the householder buys windows with a 20 mm gap. These windows are much more expensive than those with a 16 mm gap. It is not worth the householder paying the extra cost to buy 20 mm windows rather than 16 mm windows. Explain this in terms of energy efficiency. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (d) Windows are given an energy rating, from A down to G. The diagram shows the energy label from one type of double glazed window. All new double glazed windows must have an energy rating of C or above. Windows having a C rating have a U-value of 1.9. Which windows given in the table would the householder be unable to buy? ............................................................................................................ ............ (1) (e) Glass transmits infrared radiation and visible light. The amount transmitted depends on the type and thickness of the glass. The data from tests on two different types of glass is displayed in the graph below. A homeowner has a glass conservatory built on the back of the house. The homeowner tells the builder that the inside of the conservatory should stay as cool as possible throughout the summer. Explain why the builder uses ‘Type B’ glass for the conservatory. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (Total 7 marks) Q8. The instruction booklet for a washing machine contains the following information. Wash cycle HOT COOL FAST (a) Average power during cycle 1.6 kW 1.1 kW 1.2 kW Time taken to run cycle 2 hours 1 ¼ hours ¾ hour Electricity costs 15 pence per kilowatt-hour. Calculate, in pence, the cost of using the washing machine for one HOT wash cycle. Write down the equation you use, and then show clearly how you work out your answer. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ Cost = ................................... pence (2) (b) Why does it cost more to use the washing machine on the HOT cycle than on the COOL or the FAST cycle? ............................................................................................................ ............ ............................................................................................................ ............ (1) (Total 3 marks) Q9. (a) The diagram shows a longitudinal wave being produced in a stretched spring. (i) Use the bold words from the diagram to complete the following sentence. Put only one word in each space. A longitudinal wave is one in which the ..................................... causing the wave is parallel to the ..................................... of energy transfer. (2) (ii) Name the type of energy that is transferred by longitudinal waves. .................................................................................................. ............. (1) (b) The diagram shows water waves made by a wave machine in a swimming pool. Every second, two waves go past a person standing in the swimming pool. The waves have a wavelength of 0.8 metres. Calculate the speed of the water waves. Write down the equation you use, and then show clearly how you work out your answer. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ Wave speed = ......................................... m/s (2) (c) The graph shows how the speed of deep ocean waves depends on the wavelength of the waves. What can you conclude from the graph? ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (Total 7 marks) Q10. Scientists have observed that the wavelengths of the light given out from galaxies that are moving away from the Earth are longer than expected. (a) (i) What name is given to this observation? .................................................................................................. ............. (1) (ii) Draw a ring around the correct answer to complete the following sentence. shrinking. This observation gives evidence for the idea that the Universe is not changing. expanding. (1) (b) The graph shows that there is a link between the speed at which a galaxy moves away from the Earth and the distance of the galaxy from the Earth. The positions of three galaxies, A, B and C, are marked on the graph. From which galaxy, A, B or C, would the wavelength of the light reaching the Earth seem to have changed the most? Galaxy ............................................. Give a reason for your answer. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (Total 4 marks) Q11. (a) The diagram shows a ray of light being reflected by a plane mirror. Which of the angles, a, b, c or d, is: the angle of incidence; the angle of reflection? (2) (b) The diagram shows a road junction seen from above. A mirror placed at the side of the road allows the driver of car X to see car Y. Using the same mirror symbol given in part (a), draw a plane mirror to show how it should be placed so that the driver of car X can see car Y. (2) (Total 4 marks) Q12. Marbles inside a box can be used as a model for the particles in a solid, a liquid or a gas. Use words from the box to complete the following sentences. Each word can be used once, more than once or not at all. gas (a) liquid solid The particles in a ............................................ vibrate about fixed positions. (1) (b) The particles in a .......................................... move at high speed in any direction. (1) (c) The particles in a ............................................ are arranged in a pattern. (1) (Total 3 marks) Q13. (a) The block diagram shows the important parts of a coal burning power station. Use words from the box to complete the block diagram boiler condenser furnace generator (2) (b) The diagram shows the energy transformations in a coal burning power station. Calculate the efficiency of the power station. Write down the equation you use, and then show clearly how you work out your answer. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ Efficiency = ............................................ (2) (c) Draw a ring around the correct answer to complete the following sentence. If fewer coal burning power stations are used to generate electricity the amount of decrease. carbon dioxide emitted into the atmosphere will not change. increase. (1) (d) Some types of power station generate electricity by burning a biofuel. Give one example of a biofuel. ............................................................................................................ ............ (1) (e) Nuclear power stations generate electricity without burning a fuel. Name the process by which a nuclear fuel provides the energy needed to generate electricity. ............................................................................................................ ............ (1) (Total 7 marks) Q14. The diagrams in List A show three electrical appliances. Each appliance is designed to transfer electrical energy. Draw one straight line from each appliance in List A to the useful energy output produced by that appliance in List B. Draw only three lines. (Total 3 marks) Q15. The diagram shows the National Grid system. Transformers X and Y are an essential part of the National Grid system. Explain why. ..................................................................................................................... ............ ..................................................................................................................... ............ ..................................................................................................................... ............ ..................................................................................................................... ............ ..................................................................................................................... ............ ..................................................................................................................... ............ ..................................................................................................................... ............ ..................................................................................................................... ............ ..................................................................................................................... ............ (Total 4 marks) Q16. The picture shows a food processor, which is used to grate, shred, liquidise and mix food. The table gives some information about the food processor. (a) Energy input Electrical Useful energy output Kinetic Power rating 1200 watts Efficiency 0.8 The food processor is used for a total of 30 minutes a day. Calculate the cost of the energy wasted by the food processor each day. Electricity costs 15 p per kilowatt-hour. Write down the equations you use, and then show clearly how you work out your answer. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ Cost of waste energy = ...................................... p (4) (b) Explain what happens to the waste energy. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (Total 6 marks) Q17. The visible part of the electromagnetic spectrum from a star includes a dark line. This line is at a specific wavelength. The diagram shows the position of the dark line in the spectrum from the Sun and in the spectrum from a distant galaxy. (a) Explain how the spectrum ‘shift’ of the dark line supports the theory that the Universe began from a very small initial point. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (3) (b) Name one other piece of evidence that supports the theory that the Universe began from a very small initial point. ............................................................................................................ ............ (1) (Total 4 marks) Q18. (a) The diagram shows a tray of marbles being shaken from side to side. As this happens some of the marbles jump out of the tray. Explain how the tray of marbles is acting as a model for the evaporation of a liquid. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (b) Before giving an injection, a nurse dabs some alcohol onto the patient’s arm. This makes the patient’s skin feel cold. Explain what happens to make the patient’s skin feel cold. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (2) (c) The graph shows that the molecules in a liquid do not all have the same speed. Use the information in the graph to explain why a liquid cools down when it evaporates. ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ ............................................................................................................ ............ (5) (Total 9 marks) Q19. The table shows the electromagnetic spectrum. Three types of wave have been missed out. (i) Use words from the box to complete the table. infra red rays radio waves X-rays (2) (ii) Which one of the following gives a use of gamma rays? Put a tick ( ) in the box next to your choice. to communicate with satellites to see objects to kill cancer cells (1) (iii) Complete the following sentence by drawing a ring around the correct word in the box. energy All electromagnetic waves move gases from one place to another. particles (1) (Total 4 marks) Q20. (a) The picture shows a speed gun being used to measure how fast a tennis player hits the ball. Some of the microwaves from the speed gun are absorbed by the ball and some are reflected by the ball. (i) Complete the following sentence by choosing one of the phrases from the box. longer than the same as shorter than The wavelength of the microwaves reflected from the ball are ................................................................... the wavelength of the microwaves from the speed gun. (1) (ii) Complete the following sentence by drawing a ring around the correct line in the box. decrease slightly When the ball absorbs microwaves, its temperature will not change increase slightly (1) (b) The microwaves reflected from the ball have a higher frequency than the microwaves from the speed gun. The graph shows how the difference between the two frequencies depends on the speed of the ball. (i) Describe the pattern that links the difference between the two frequencies and the speed of the ball. .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) The speed gun measures the difference between the two frequencies as 3200 Hz. Use the graph to find the speed of the tennis ball. Show clearly on the graph how you obtain your answer. Speed of the tennis ball = .............................. m/s (2) (iii) Which one of the following gives the reason why the data has been shown as a line graph and not as a bar chart? Put a tick ( ) in the box next to your choice. Frequency and speed are both categoric variables. Frequency and speed are both continuous variables. Speed is a continuous variable and frequency is a categoric variable. (1) (Total 6 marks) Q21. The picture shows a solar-powered aircraft. The aircraft has no pilot. Photo by NASA. (a) Use words from the box to complete the following sentence. electrical heat light sound Solar cells are designed to transform .............................................................. energy into .............................................................. energy. (2) (b) On a summer day, 175 000 joules of energy are supplied to the aircraft’s solar cells every second. The useful energy transferred by the solar cells is 35 000 joules every second. (i) Use the equation in the box to calculate the efficiency of the solar cells. Show clearly how you work out your answer. .................................................................................................. ......................... .................................................................................................. ......................... Efficiency = .............................................................. (2) (ii) What happens to the energy that is not usefully transferred by the solar cells? .................................................................................................. ......................... (1) (c) The aircraft propellers are driven by electric motors. As well as the solar cells, there are fuel cells that provide additional power to the electric motors. (i) Suggest one advantage of the aircraft having fuel cells as well as the solar cells. .................................................................................................. ......................... (1) (ii) Give one environmental advantage of using electric motors to drive the aircraft propellers rather than motors that burn a fuel. .................................................................................................. ......................... .................................................................................................. ......................... (1) (iii) Eventually, the designers want to produce an unmanned aircraft that can fly at twice the height of a passenger jet for up to six months. Suggest one possible use for an aircraft such as this. .................................................................................................. ......................... .................................................................................................. ......................... (1) (Total 8 marks) Q22. The bar chart shows the different energy sources used to generate the UK’s electricity in 2007. (a) (i) The wind is a renewable energy source. Name one more renewable energy source used to generate electricity. .................................................................................................. ......................... (1) (ii) Complete the following sentence by drawing a ring around the correct line in the box. decrease Using less fossil fuels to generate electricity will not change increase amount of carbon dioxide emitted into the atmosphere. (1) (b) The graph shows how the demand for electricity in the UK varied over one day in the winter. (i) Describe how the demand for electricity varied between 4.00 am and 10.00 am. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) the (ii) Which type of power station has the fastest start-up time? Draw a ring around your answer. coal natural gas nuclear oil (1) (Total 5 marks) Q23. A vacuum flask is designed to reduce the rate of heat transfer. (a) (i) Complete the table to show which methods of heat transfer are reduced by each of the features labelled in the diagram. The first row has been done for you. Feature Conduction Convection Radiation vacuum silvered surfaces plastic cap (2) (ii) Explain why the vacuum between the glass walls of the flask reduces heat transfer by conduction and convection. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (b) The diagram shows a gas flame patio heater. (i) Explain why the top surface of the reflecting hood should be a light, shiny surface rather than a dark, matt surface. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (ii) Most of the chemical energy in the gas is transformed into heat. A small amount of chemical energy is transformed into light. Draw and label a Sankey diagram for the patio heater. (2) (iii) State why the total energy supplied to the patio heater must always equal the total energy transferred by the patio heater. .................................................................................................. ......................... .................................................................................................. ......................... (1) (Total 9 marks) Q24. The pictures show three different types of electric heater. (a) The ceramic heater is run on full power for 5 hours. Use the following equation to calculate, in kilowatt-hours, the amount of energy transferred from the mains to the heater. energy transferred = power × time Show clearly how you work out your answer. ............................................................................................................ ......................... ............................................................................................................ ......................... Energy transferred = .............................. kilowatt-hours (2) (b) Which heater will be the most expensive to run on its highest heat setting? ............................................................................................................ ......................... (1) (c) A heater is needed for a small office. Comparing each type of heater with the other two, give one advantage of using each type of heater in the office. oil-filled panel heater ................................................................................................. ............................................................................................................ ......................... fan heater .................................................................................................. .................. ............................................................................................................ ......................... ceramic heater .................................................................................................. ........... ............................................................................................................ ......................... (3) (Total 6 marks) The bar chart shows how the UK’s electricity demands in 2007 were Q25. met. (a) What proportion of electricity was generated using renewable energy sources? Show clearly how you work out your answer. ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (b) By 2020, most of the UK’s nuclear reactors and one-third of coalfired power stations are due to close, yet the demand for electricity is expected to increase. Four students, A, B, C and D, were asked how a demand of 380 billion kilowatt-hours could be met. They made the suggestions given in the table. Student Fossil fuels Nuclear Renewable Bought from other countries (i) A 200 100 40 40 B 80 240 40 20 C 160 80 100 40 D 280 0 100 0 Which student has made the suggestion most likely to result in the lowest carbon dioxide emissions? .................................................................................................. ......................... Give a reason for your answer. .................................................................................................. ......................... .................................................................................................. ......................... (2) (ii) Suggest one realistic way in which a householder could help to reduce the annual electricity demand. .................................................................................................. ......................... .................................................................................................. ......................... (1) (c) To increase the amount of electricity generated using renewable energy resources would probably involve erecting many new wind turbines. The graph shows the power curve of a wind turbine. (i) Describe, in detail, how the power output of the turbine varies with the wind speed. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (3) (ii) Give one disadvantage of using wind turbines to generate a high proportion of the electricity required in the UK. .................................................................................................. ......................... .................................................................................................. ......................... (1) (Total 9 marks) Q26. (a) Microwaves are one type of electromagnetic wave. (i) Which type of electromagnetic wave has a lower frequency than microwaves? .................................................................................................. ......................... (1) (ii) What do all types of electromagnetic wave transfer from one place to another? .................................................................................................. ......................... (1) (b) The picture shows a tennis coach using a speed gun to measure how fast the player serves the ball. (i) The microwaves transmitted by the speed gun have a frequency of 24 000 000 000 Hz and travel through the air at 300 000 000 m/s. Use the equation in the box to calculate the wavelength of the microwaves emitted from the speed gun. wave speed = frequency × wavelength Show clearly how you work out your answer. .................................................................................................. ......................... .................................................................................................. ......................... Wavelength = .............................. m (2) (ii) Some of the microwaves transmitted by the speed gun are absorbed by the ball. What effect will the absorbed microwaves have on the ball? .................................................................................................. ......................... .................................................................................................. ......................... (1) (iii) Some of the microwaves transmitted by the speed gun are reflected from the moving ball back towards the speed gun. Describe how the wavelength and frequency of the microwaves change as they are reflected from the moving ball. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (Total 7 marks) Q27. Electricity is generated in power stations. It is then sent to all parts of the country through a network of cables. (a) Complete the following sentence by using one of the words in the box. Grid Power Supply The network is called the National ............................................................................ . (1) (b) In the diagram, A, B, C and D are transformers. (i) Which transformer, A, B, C or D, is a step-up transformer? Transformer .............................. (1) (ii) Which transformer, A, B, C or D, will supply homes, offices and shops? Transformer .............................. (1) (c) Complete the following sentence by drawing a ring around the correct line in the box. In a step-down transformer, the potential difference (p.d.) across the less than primary coil is the same as the p.d. across the secondary coil. more than (1) (Total 4 marks) Q28. A microphone and a cathode ray oscilloscope (CRO) can be used to show the pattern of a sound wave. Four sound wave patterns, A, B, C and D, are shown. They are all drawn to the same scale. (a) Which one of the patterns has the smallest amplitude? ..................................................... (b) Which one of the patterns has the lowest frequency? ........................................................ (Total 2 marks) Q29. A puppy can see an image of himself in a plane mirror. The diagram shows how the puppy can see his disc. (a) On the diagram, use a ruler to draw a ray to show how the puppy can see the top of his ear, which is marked as T. (3) (b) What is a plane mirror? ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (Total 4 marks) Q30. The diagram shows the energy transformations produced by a TV. (a) Use words from the diagram to complete the following sentence. The TV is designed to transform ............................................................ energy into light and ................................................................... energy. (2) (b) Which one of the following statements is false? Put a tick ( ) in the box next to the false statement. The energy transformed by the TV makes the surroundings warmer. The energy transformed by the TV becomes spread out. The energy transformed by the TV will be destroyed. (1) (c) Two different makes of television, A and B, transform energy at the same rate. Television A wastes less energy than television B. Complete the following sentence by drawing a ring around the correct line in the box. Television A has a higher efficiency than the same efficiency as a lower efficiency than television B. (1) (Total 4 marks) Q31. Wind and tides are renewable energy sources that are used to generate electricity. (a) Complete each sentence by putting a tick ( ) in the box next to the correct answer. (i) The wind is: a predictable energy source. a constant energy source. an unreliable energy source. (1) (ii) The tides are: a predictable energy source. a constant energy source. an unreliable energy source. (1) (b) If wood is to be used as a renewable energy source, what must be done each time a tree is chopped down? ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (c) In the UK, electricity is generated using renewable and nonrenewable energy sources. The graph shows the percentage of electricity generated using renewable energy sources between 1990 and 2005. Complete the following sentence by drawing a ring around the correct line in the box. In 2015, the percentage of electricity generated using renewable energy sources is most likely to be greater than 4% . equal to 4% less than 4% (1) (Total 4 marks) Q32. (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. ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (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. ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (c) Polar bears and reindeer are adapted to live in cold environments. Use the words in the box to complete the following sentences. conduction (i) convection radiation The white colour of a polar bear’s fur helps to keep the polar bear warm by reducing the heat lost by .................................................. . (1) (ii) The hairs of a reindeer are hollow. The air trapped inside the hairs reduces the heat lost by .................................................. . (1) (Total 5 marks) Q33. Electrical appliances that are left on standby still use energy. The bar chart compares the average amount of ‘standby energy’ wasted each year in every home in five countries. (i) In which country are the homes that waste, on average, the smallest amount of ‘standby energy’? Draw a ring around your answer. Australia USA France Japan UK (1) (ii) Suggest a reason why an average value is used for the ‘standby energy’ wasted in the homes. .................................................................................................. ......................... .................................................................................................. ......................... (1) (b) (i) Australia has one of the lowest electricity prices in the world. How does this low price seem to affect the amount of ‘standby energy’ wasted? .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) In Australia, most electricity is generated in coal-burning power stations. The Australian government wants less electricity to be wasted. Wasting less electricity would be good for the Australian environment. Explain why. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (c) Energy is not usually measured in kilowatt-hours. Which one of the following units is usually used to measure energy? Draw a ring around your answer. hertz joule watt (1) (d) (i) Electricity in Japan costs the equivalent of 17 pence per kilowatt-hour. Use the information in the bar chart and the equation in the box to calculate how much the ‘standby energy’ used in an average Japanese home costs each year. total cost = number of kilowatt-hours × cost per kilowatt-hour Show clearly how you work out your answer. Give your answer in pence. .................................................................................................. ......................... .................................................................................................. ......................... Cost = ........................................ pence (3) (ii) In Japan, the largest proportion of electricity is generated using nuclear fuels. Which one of the following statements gives a good reason for using nuclear fuels to generate electricity? Put a tick ( ) in the box next to your answer. A nuclear power station is very expensive to build. A small amount of nuclear fuel generates a large amount of electricity. It is easy to store nuclear waste safely. (1) (Total 10 marks) Q34. (a) Some scientists think that there is a link between using a mobile phone and some types of illness. Other scientists disagree. They say that the evidence is limited and unreliable. (i) Suggest what scientists could do to show a link between using a mobile phone and illness. .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) How could scientists improve the reliability of the evidence? .................................................................................................. ......................... .................................................................................................. ......................... (1) (iii) Complete the following passage by drawing a ring around the word in the box that is correct. There has been little or no experimental research into the health of children who use mobile phones. economic This is partly because of the environmental issues involved in using ethical children in scientific research. (1) (b) Before being sold, new mobile phones must be tested and given a SAR value. The SAR value is a measure of the energy absorbed by the head while a mobile phone is being used. The table gives the SAR value for three mobile phones made by different companies. To be sold in the UK, a mobile phone must have a SAR value lower than 2.0 W/kg. (i) Mobile phone SAR value in W/kg J 0.18 K 0.86 L 1.40 All companies use the same test to measure a SAR value. Why is using the same test important? .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) Would the companies that make the mobile phones, J, K and L, be correct to claim that these three phones are totally safe to use? Answer yes or no. .............................. Give a reason for your answer. .................................................................................................. ......................... .................................................................................................. ......................... (1) (c) Devices designed to protect a mobile phone user from microwave radiation are now available. Why is it important that these devices are tested by scientists who are not working for the company that makes the devices? ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (Total 6 marks) Q35. (a) The diagram shows the energy transformations produced by a TV. (i) Use the information in the diagram and the equation in the box to calculate the efficiency of the TV. efficiency = Show clearly how you work out your answer. .................................................................................................. ......................... .................................................................................................. ......................... Efficiency = .............................. (2) (ii) What eventually happens to the useful energy transferred by the TV? .................................................................................................. ......................... .................................................................................................. ......................... (1) (b) Electrical appliances left on standby use energy. The bar chart shows the power for the appliances that one family leaves on standby when they go on holiday. The family is on holiday for a total of 175 hours. (i) Use the information in the bar chart and the equation in the box to calculate the energy wasted by leaving the compact stereo on standby while the family is on holiday. energy transferred (kilowatt-hour, kWh) = power (kilowatt, kW) × time (hour, h) Show clearly how you work out your answer. .................................................................................................. ......................... .................................................................................................. ......................... Energy wasted = .............................. kilowatt-hours (2) (ii) Electricity costs 12 p per kilowatt-hour. Use the equation in the box to calculate the cost of leaving the compact stereo on standby while the family is on holiday. total cost = number of kilowatt-hours × cost per kilowatt-hour Show clearly how you work out your answer. .................................................................................................. ......................... Cost = .............................. p (1) (c) A headline from a recent newspaper article is shown below. Explain why leaving appliances on standby damages the environment. ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (Total 8 marks) Q36. The pie charts show the relative proportions of electricity generated in Japan from different energy sources in 1975 and 2005. (a) Describe the main differences in the energy sources used in 2005 compared with 1975. ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (b) In the UK, nuclear fuels are used to generate about 21% of the total electricity supply. (i) What is the name of the process by which a nuclear fuel produces heat? .................................................................................................. ......................... (1) (ii) Explain how the heat released from a nuclear fuel is used to generate electricity in power stations. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (iii) Some people have suggested that more nuclear power stations should be built in the UK. Give two reasons to support this suggestion. 1 ......................................................................................... ............................... .................................................................................................. ......................... 2 ......................................................................................... ............................... .................................................................................................. ......................... (2) (iv) Nuclear power stations create dangerous waste. Why is the waste from a nuclear power station dangerous? .................................................................................................. ......................... .................................................................................................. ......................... (1) (c) A headline from a newspaper article is shown below. Explain the possible link between climate change and coal-burning power stations. ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (Total 9 marks) Q37. The diagram shows a fridge-freezer. (a) By which method is heat transferred through the walls of the fridgefreezer? ............................................................................................................ ......................... (1) (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. ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (c) The outside surface of the fridge-freezer is white and shiny. Give two reasons why this type of surface is suitable for a fridgefreezer. 1 .................................................................................................. ................................ ............................................................................................................ ......................... 2 .................................................................................................. ................................ ............................................................................................................ ......................... (2) (Total 4 marks) Q38. (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 ....................................................... . (2) (ii) Use words from the box to complete the sentence. the amplitude frequency half the amplitude the frequency half the The distance x marked on the diagram measures ......................................... of the sound wave. (1) (iii) Complete the sentence. The distance x becomes smaller. This is because the sound has become ......................................................................................... ................... . (1) (b) There is no air in space. Astronauts in space cannot hear sounds from outside their spacesuits. Explain this. ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (Total 6 marks) Q39. In the diagram below, a frog sits on a rock in a pond. (a) Complete the following sentences by drawing a ring around the correct line in the box. (i) The frog can see its image in the pond because the surface of the pond acts concave like a convex mirror. plane (1) (ii) Draw a ring around each of two words from the box below to describe the image in the pond. bigger virtual inverted real smaller upright (2) (b) There is an insect underneath the rock. Use a ruler to draw rays of light on the diagram to show how the frog uses reflection to see the insect. Mark the direction of the rays. (3) (Total 6 marks) Q40. A student uses a ray box and a semicircular glass block to investigate refraction. (a) What is the vertical dashed line called? ............................................................................................................ ......................... (1) (b) Which angle, v, w, x, y or z, is the angle of refraction? ............................................................................................................ ......................... (1) (c) Why has refraction taken place? ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (d) In an investigation, a student always aims the light from the ray box at point P. She moves the ray box to give different values of angle v. She records angle y for each of these values. The table shows her results. Angle v measured in degrees Angle y measured in degrees 30 19 40 25 50 31 60 35 70 39 80 41 The student studies the data and comes to the following conclusion. Angle y is directly proportional to angle v. Her friend says that this conclusion is not correct. (i) Use data from the table to explain why the conclusion is not correct. .................................................................................................. ......................... .................................................................................................. ......................... (2) (ii) Write a correct conclusion for the experiment. .................................................................................................. ......................... .................................................................................................. ......................... (1) (iii) Why is your conclusion only valid when angle v is between 30° and 80°? .................................................................................................. ......................... .................................................................................................. ......................... (1) (Total 7 marks) Q41. (a) Each letter A, B, C, D and E represents an energy transformation. A electrical to gravitational potential B electrical to heat C electrical to kinetic D electrical to light E electrical to sound Match each of the following devices to the useful energy transformation that it is designed to make. Write the correct letter, A, B, C, D or E, in the box below the device. Use each letter once or not at all. (3) (b) The bar chart shows the power of three electric kettles. (i) What is the power of kettle Y? .................................................................................................. ......................... (1) (ii) In one week each kettle is used for a total of 30 minutes. Which kettle costs the most to use? .................................................................................................. ......................... (1) (iii) A new ‘express boil’ kettle boils water faster than any other kettle. Draw a fourth bar on the chart to show the possible power of an ‘express boil’ kettle. (1) (c) Some friends are going on holiday. They want to be able to boil water to make their own hot drinks. They cannot decide which to take, a travel kettle or a small portable immersion heater that can be placed in a mug. Travel Kettle Immersion heater • 1 k W element • • Holds 1 litre • Works on 110 V or 230 V • Heates up to 0.5 litres of water • Washable water filter (i) 0.4 k W element • Works on 230 V only • Small compact size Give one advantage of taking the travel kettle. .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) Give one advantage of taking the immersion heater. .................................................................................................. ......................... .................................................................................................. ......................... (1) (Total 8 marks) Q42. (a) Infra red radiation can be reflected, absorbed and transmitted by glass. (i) What percentage of infra red is absorbed by the glass? .................................................................................................. ......................... (1) (ii) Complete the following sentence by drawing a ring around the correct word or phrase. increases The absorbed infra red does not change the temperature of the glass. decreases (1) (b) Two of the following statements are true. One of the statements is false. Tick ( ) the boxes next to the two true statements. All objects absorb infra red radiation. Black surfaces are poor emitters of infra red radiation. A hot object emits more infra red than a cooler object. (1) (c) The following statement is false. Black surfaces are good reflectors of infra red radiation. Change one word in this statement to make it true. Write down your new statement. ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (Total 4 marks) Q43. (a) Water waves are a renewable energy source. The government wants more electricity to be generated from renewable energy sources. Some people do not think this is a good idea. What reasons could a government scientist give to show people that using more renewable energy sources is a good idea? ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (b) The diagram shows a wave-powered generator. The generator transforms kinetic energy from the waves to electrical energy. AQA GCSE SCIENCE CORE FOUNDATION STUDENT’S BOOK by Graham Hill, Nigel Heslop, Christine Woodward,Steve Witney and Toby Houghton. Published by Hodder and Stoughton 2006 © Reproduced by permission of John Murray (Publishers) Ltd The following sentences describe how the wave generator works. The sentences are in the wrong order. R S T U V Waves push air up and down a chamber inside the building. The turbine turns the generator. The generator transforms kinetic energy to electrical energy. The air rushes through a turbine making it spin. Strong waves move towards the wave-powered generator. Arrange these sentences in the correct order. Start with letter V. V (3) (Total 5 marks) Q44. (a) Electricity is distributed from power stations to consumers along the National Grid. (i) Transformers are part of the National Grid. Transformers are efficient devices. What is meant by a device being efficient? .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) When electricity flows through a cable, some energy is transformed into heat. Explain how the National Grid system reduces the amount of energy lost as heat. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (b) Read this information taken from a recent newspaper article. • Researchers have found that children living close to overhead power cables are more likely to develop leukaemia. • The researchers studied two groups of children. One group had developed leukaemia, the other group was healthy. • Although the researchers found a link, they are unable to explain why it happened. They say that the results may have happened by chance. • Other factors that have not been investigated, such as the environment, the geographical area or the children’s genes, could be important. • A cancer research charity said that childhood leukaemia was most likely to be caused by factors that parents were unable to control. (i) Why did the researchers study a group of healthy children? .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) The information does not say how many children were studied. Why should this data have been included in the article? .................................................................................................. ......................... .................................................................................................. ......................... (1) (iii) The researchers could not be certain that the overhead power cables were responsible for the increased chance of children developing leukaemia. Explain why. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (iv) The results of the research carried out by scientists may worry some people. What do you think scientists should do? Put a tick ( ) in the box next to your choice. Scientists should publish their research findings straight away. Scientists should not publish their research findings until they have found out as many facts as possible. Give a reason for your choice. .................................................................................................. ......................... .................................................................................................. ......................... (1) (Total 8 marks) Q45. The diagram shows the label from a new freezer. (a) An old freezer has an energy consumption per year of 350 kWh. Use the equation in the box to calculate the extra cost of using the old freezer for one year compared with using a new ‘A’ rated freezer. total cost = number of kilowatt-hours × cost per kilowatt-hour Assume 1 kilowatt-hour (kWh) of energy costs 12 p. Show clearly how you work out your answer. ............................................................................................................ ......................... ............................................................................................................ ......................... Extra cost per year = £ .............................. (2) (b) The price of the new freezer was reduced in a sale. Reducing the price reduces the payback time for replacing the old freezer from 12 years to 9 years. Calculate, in pounds, how much the new freezer was reduced in the sale. Show clearly how you work out your answer. ............................................................................................................ ......................... ............................................................................................................ ......................... Price reduced by = £ ........................................ (2) (c) An advertisement in a shop claims that: ‘Replacing an old freezer with a new ‘A’ rated freezer will benefit the environment.’ Do you agree that replacing the freezer will benefit the environment? Answer yes or no. .............................. Explain the reasons for your answer. ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (Total 6 marks Q46. (a) In winter, energy is transferred from the warm air inside a house to the air outside. (i) What effect will the energy transferred from the house have on the air outside? .................................................................................................. ......................... (1) (ii) What would happen to the energy transfer if the temperature inside the house were reduced? Assume the temperature outside the house does not change. .................................................................................................. ......................... (1) (b) To increase energy efficiency, a householder installs a heat exchanger to an outside wall of the house. The heat exchanger uses heat from the air outside to warm the inside of the house. The diagram shows the idea of the heat exchanger. Physics Through Applications edited by J Jardine et el (OUP, 1989), copyright © Oxford University Press, reprinted by permission of Oxford University Press. (i) Why does the heat exchanger cost money to run? .................................................................................................. ......................... (1) (ii) The heat exchanger is cost effective in reducing energy consumption. Explain why. .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (Total 5 marks) ## (a) The wavelengths of four different types of electromagnetic wave, including visible light waves, are given in the table. Type of wave Wavelength Visible light 0.0005 mm A 1.1 km B 100 mm C 0.18 mm Which of the waves, A, B or C, is an infra red wave? .................................... (1) (b) A TV station broadcasts at 500 000 kHz. The waves travel through the air at 300 000 000 m/s. Use the equation in the box to calculate the wavelength of the waves broadcast by this station. wave speed = frequency × wavelength Show clearly how you work out your answer. ............................................................................................................ ......................... ............................................................................................................ ......................... Wavelength = .............................. m (2) (c) What happens when a metal aerial absorbs radio waves? ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (d) Stars emit all types of electromagnetic waves. Telescopes that monitor X-rays are 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? ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (Total 6 marks) Q48. The ‘steady state’ theory was once a popular alternative to the ‘big bang’ theory. The ‘steady state’ theory suggested that the universe, although expanding, had no origin and it has always existed. As the universe expands, a small amount of matter is created to keep the universe looking exactly the same all of the time. (a) When considering the origin of the universe, what is the difference between the ‘big bang’ theory and the ‘steady state’ theory? ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (b) The light from distant galaxies shows a red-shift. (i) What is red-shift? .................................................................................................. ......................... .................................................................................................. ......................... (1) (ii) Why does red-shift provide evidence to support both the ‘bigbang’ theory and the ‘steady state’ theory? .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... .................................................................................................. ......................... (2) (c) The ‘steady state’ theory was important in encouraging new research into the universe. Suggest a reason why scientists were keen to carry out new research. ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (d) Scientists can answer many questions about the universe, but not the question: ‘Why was the universe created?’ Suggest a reason why this question cannot be answered by scientists. ............................................................................................................ ......................... ............................................................................................................ ......................... (1) (Total 7 marks) Q49. When sound waves reach a material, some of the energy of the sound is reflected and some is transmitted through the material. (a) Complete the sentence. Sound waves are caused by ........................................................................................ (1) (b) The graphs J, K, L and M represent the sound energy reflected from a surface. The graphs are all drawn to the same scale. Which graph shows the greatest total sound energy output from the surface? Graph .................................................... (1) (c) The proportion of the sound energy which is reflected or transmitted depends on the material which receives the sound. A student investigates different materials. The diagram shows how a student sets up her equipment. (i) Using a pencil and ruler to draw on the diagram, show how microphone X receives reflected sound. (2) (ii) The student tests four materials. Each sheet of material is 1 mm thick. This has been glued onto a block of expanded polystyrene. Why does the student use the same size of expanded polystyrene block and the same sound level for each test? .................................................................................................. ......................... .................................................................................................. ......................... (1) (iii) The table shows the readings for the sound level transmitted to microphone Y. Sound level from loudspeaker in arbitrary units [A] Surface material Sound level transmitted to microphone Y in arbitrary units 60 paper 39 60 plaster 18 60 cloth 31 60 wood 15 Which surface material transmits the smallest proportion of the sound? ......................................................................................... ....................... (1) [B] What proportion is this? ......................................................................................... ....................... (1) (d) People living in a flat have very noisy neighbours who are always playing loud music. Suggest one practical idea to reduce the amount of noise transmitted into the flat through the walls and explain how your idea will work. ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... ............................................................................................................ ......................... (2) (Total 9 marks) Q50. The pictures show six different household appliances. (a) Four of the appliances, including the fan heater, are designed to transform electrical energy into heat. Name the other three appliances designed to transform electrical energy into heat. 1 .................................................................................................. ............................... 2 .................................................................................................. ............................... 3 .................................................................................................. ............................... (3) (b) Complete the following sentence using one of the words from the box. chemical heat kinetic sound Energy that is not usefully transformed by the fan heater is wasted as ................................................. energy. (1) (c) The table gives information about two different fan heaters. Useful energy transferred each second in joules Wasted energy transferred each second in joules Fan heater L 1200 10 Fan heater M 1200 20 Complete the following sentence by drawing a ring around the line in the box that is correct. is more efficient than Fan heater L has the same efficiency as fan heater M. is less efficient than (1) (Total 5 marks) Q51. (a) Different energy sources are used to generate electricity. Which two of the energy sources in the box are likely to be used up first? Draw a ring around each of your answers. gas oil Sun tides waves wind (2) (b) The diagram shows a geothermal power station. Hot rocks in the Earth’s crust heat water to produce steam. The steam is used to drive turbines that turn electrical generators. How is the way in which a geothermal power station generates electricity the same as the way in which a coal burning power station generates electricity? ............................................................................................................ ....................... ............................................................................................................ ....................... (1) (c) The graph shows how the temperature of the rocks in the Earth’s crust depends on how far the rocks are below the Earth’s surface. Estimate the temperature of the rocks 5 kilometres below the Earth’s surface. Show clearly how you have used the graph to get your answer. ............................................................................................................ ....................... ............................................................................................................ ....................... Temperature = ................................................. °C (2) (d) Scientists have estimated that one quarter of the world’s electricity could be generated using geothermal energy. Give one reason that scientists might use to persuade a government to spend large amounts of money building geothermal power stations. ............................................................................................................ ....................... ............................................................................................................ ....................... (1) (Total 6 marks) Q52. A householder was out shopping when her electricity meter reading should have been taken. The electricity company estimated the reading and sent the following bill. Unfortunately, the bill was damaged in the post. (a) Use the equation in the box to calculate the cost of the electricity used between 12 June and 13 September. total cost = number of kilowatt-hours × cost per kilowatt-hour Show clearly how you work out your answer. ............................................................................................................ ........................ ............................................................................................................ ........................ Total cost = ................................................. (2) (b) The estimated reading shown on the bill was not very accurate. The correct reading was 62920. How many kilowatt-hours of electricity had the householder actually used between 12 June and 13 September? ............................................................................................................ ........................ ............................................................................................................ ........................ (2) (Total 4 marks) M1. (a) decrease in (proportion of) oil as reserves are decreasing 1 increase in (proportion of) coal / nuclear / gas / as new reserves / more nuclear power stations built 1 no marks are awarded for simply describing the differences (b) (i) a prediction 1 forecast based on scientific evidence 1 (ii) less methane goes into the atmosphere accept air for atmosphere 1 therefore making global warming less rapid 1 (c) idea that many devices transform electricity into other useful forms of energy 1 example related to public health eg refrigeration / production of vaccines / X-ray machines 1 example related to modern communications eg internet / telephones 1 [9] M2. (a) 40 (cm/s) correct answer an answer 0.4 m/s gains full credit if answer is incorrect allow 1 mark for correct wavelength λ = 8 cm or allow 2 marks for correct substitution into the correct equation, ie. V = 5 x 8 or allow 2 marks for clearly stated wrong wavelength correctly substituted into correct equation and correctly calculated, ie λ = 16 cm/s V = 5 x 16 = 80 3 (b) line extended following pattern 1 14 m/s accept their numerical value, if not 14, provided the first mark has been awarded 1 [5] M3. (a) ray drawn from tooth to mirror to eye 1 angle I = angle R judged by eye 1 at least one arrow in correct direction do not credit conflicting arrows 1 if no ruler used maximum mark is 2 (b) virtual 1 upright 1 [5] M4. (a) because black is a good absorber of radiation 1 there will be a faster transfer of energy allow the temperature of the water rises faster 1 (b) 16 800 000 allow 1 mark for substitution into correct equation ie 100 × 4200 × 40 2 (c) 7 allow ecf from part (b) 1 (d) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. No relevant content. 0 marks There is a brief description of the advantages and disadvantages of using solar energy to heat the water rather than using an electric immersion heater, including either advantages or disadvantages from the examples below. Level 1 (1-2 marks) There is a description of some of the advantages and disadvantages of using solar energy to heat the water rather than using an electric immersion heater, with at least one advantage and one disadvantage from the examples below. Level 2 (3-4 marks) There is a clear, balanced and detailed description of the advantages and disadvantages of using solar energy to heat the water rather than using an electric immersion heater, with a minimum of two advantages and two disadvantages from the examples below. Level 3 (5-6 marks) examples of the points made in the response advantages accept specific examples of polluting gases • a renewable energy source • energy is free • does not pollute the atmosphere • no fuel is burnt • energy can be stored (in the water) disadvantages accept unreliable energy source • only available in daylight hours • availability fluctuates • insufficient hours of sunlight in some countries • average low intensity in some countries [11] M5. (a) (i) to compare mobile phone usage between the two groups 1 (ii) enough data to indicate relationships or reduce effect of anomalous data 1 (b) (i) ethical 1 (ii) research may be biased (in favour of companies) 1 negative effects on health may not get published accept negative effects on health may be played down 1 (iii) it allows people to easily identify lower risk phones 1 and this allows people to make a more informed choice accept and this allows a comparison to be made 1 [7] M6. (a) energy needed to produce evaporation comes from the body 1 therefore this stops the body temperature rising 1 (b) the silver space blanket reflects energy back to the runner accept heat for energy 1 and this reduces the energy transferred from the body by radiation 1 [4] M7. (a) 1 1 (b) 3 and 4 or 1 and 2 1 (c) U-values for the 20 mm windows are the same or higher than those for the 16 mm windows 1 therefore the 20 mm windows are no more energy efficient than 16 mm windows accept so the 16 mm windows are as energy efficient as 20 mm windows 1 (d) 1 and 2 must have both and no other 1 (e) Type B glass transmits less infrared than Type A glass accept radiation / heat for infrared accept Type B glass absorbs more infrared than Type A glass 1 and as infrared has a heating effect the conservatory will remain cooler 1 [7] M8. (a) 48 allow 1 mark for calculating energy as 3.2 kWh 2 (b) largest power and longest time to run 1 [3] M9. (a) (i) oscillation 1 direction 1 correct order only (ii) sound 1 (b) 1.6 allow 1 mark for correct substitution into correct equation ie 2 x 0.8 2 (c) as the wavelength increases so does the wave speed 1 extra information eg wave speed increases faster between 0-40 m than between 100-140 m or not in proportion 1 [7] M10. (a) (i) red-shift 1 (ii) expanding 1 (b) C 1 it is furthest from the Earth or it is furthest away or it has the largest red-shift or it is moving (away) the fastest only score if C is chosen 1 [4] M11. (a) b 1 c 1 correct order only (b) mirror opposite road junction 1 mirror facing correct way, angle correct judged by eye 1 [4] M12. (a) solid 1 (b) gas 1 (c) solid 1 [3] M13. (a) boiler 1 generator 1 (b) 0.3 or 30% allow 1 mark for substitution of 2 correct values taken from the Sankey diagram into correct equation 2 (c) decrease 1 (d) any named biofuel eg wood, ethanol, straw 1 (e) (nuclear) fission 1 [7] M14. 3 lines correct allow 1 mark for each correct line more than 1 line drawn from any appliance and all those lines are incorrect [3] M15. transformer X reduces the current through the transmission cables accept increases p.d. across the cables 1 this reduces the energy loss from the cables 1 which increases the efficiency of the distribution system 1 transformer Y is essential as it reduces the p.d. to a safe working value for consumers 1 [4] M16. (a) 1.8 (p) these 4 marks can be broken down as follows: 1 mark for correct transformation and substitution into efficiency equation ie 0.8 × 1200 – useful power PLUS 1 mark for useful power = 960 W / 0.96 kW PLUS 1 mark for waste energy transferred = 0.24 × 0.5 or waste energy transferred = 0.12 (kWh) PLUS 1 mark for cost = 0.12 × 15 where a mathematical error has been made full credit should be given for subsequent correct method 4 (b) the waste energy is transferred as heat and sound 1 to the surroundings where it spreads out / is shared by surrounding particles accept air for surroundings 1 [6] M17. (a) the observed wavelength of the dark line from the distant galaxy has increased 1 therefore the distant galaxy must be moving away from the Earth 1 suggesting the Universe is expanding outwards from a small initial point 1 (b) existence of cosmic microwave background radiation accept existence of CMBR 1 [4] M18. (a) the marbles model / act as molecules accept atoms / particles for molecules 1 molecules leaving a liquid = evaporation or marbles leaving tray = evaporation 1 (b) to evaporate the alcohol requires energy 1 this energy is taken from the skin and the skin feels cold accept heat for energy 1 (c) there are attractive forces between molecules 1 only the fastest molecules have enough energy to break away from other molecules 1 these molecules escape from the surface of the liquid 1 therefore the average speed / energy of the remaining molecules goes down 1 the lower the average speed / energy of molecules the lower the temperature of the liquid 1 [9] ## (i) X-rays infra red (rays) radio (waves) all three in correct order allow 1 mark for 1 correct 2 (ii) to kill cancer cells 1 (iii) energy 1 [4] M20. (a) (i) shorter than 1 (ii) increase slightly 1 (b) (i) go up in the same ratio or (directly) proportional or as speed (of the tennis ball) increases so does the (difference in) frequency accept as one goes up, so does the other accept positive correlation 1 (ii) 20 (m/s) allow 1 mark for showing correct method on graph (ie horizontal or vertical line anywhere on graph) if indicated by a cross, must be ± half square of correct value) 2 (iii) frequency and speed are both continuous variables 1 [6] M21. (a) light 1 electrical correct order only 1 (b) (i) 0.2 or 1/5 accept 20% for both marks allow 1 mark for correct substitution answer of 0.2% or 20 gains 1 mark ignore units 2 (ii) wasted accept transformed to heat / other forms accept transferred to the air / surroundings sound = neutral 1 (c) (i) any one from: • can fly at night accept can fly when it is cloudy accept as a back-up • can stay in the air for longer • can fly in the winter • can fly faster increases power is neutral 1 (ii) any one from: • produces no (pollutant) gases or no greenhouse gases accept named gas accept no air pollution do not accept no pollution accept less global warming accept harmful for pollutant accept produces no carbon do not accept environmentally friendly • produces no / less noise • less demand for fuels accept any other sensible environmental advantage 1 (iii) accept any sensible suggestion eg, map the Earth’s surface / weather forecasting / spying / monitoring changes to the Earth’s atmosphere, etc do not accept ideas in terms of transporting accept use as a satellite 1 [8] M22. (a) (i) any one from: • waves do not accept water • tides • falling water accept hydroelectric • biofuel / biomass • solar accept sun / sunlight do not accept light accept solar cells / panels • geothermal do not accept heat 1 (ii) decrease 1 (b) (i) increases from 4am (to 8am) remains constant from 8am (to 10am) accept increases from 30 000 accept stays constant from 40 000 allow 1 mark for goes up then stays the same for full credit must be some indication of time or power 2 (ii) natural gas 1 [5] M23. (a) (i) silvered surfaces more than the correct number of ticks in a row negates the mark radiation 2 plastic cap conduction, convection (both required) conduction convection radiation vacuum silvered surfaces (1) plastic cap (1) (ii) any mention of air or any other substance in a vacuum scores zero because there are no particles in a vacuum accept atoms / molecules for particles accept vacuum is empty space accept there is nothing in a vacuum accept there is no air / gas in the vacuum conduction and convection need particles / medium need reference to both conduction and convection accept correct descriptions 2 (b) (i) less heat lost (to air above the heater) do not accept no heat lost light shiny surfaces are poor emitters (of radiation) accept radiators for emitters references to reflection are neutral or dull, matt surfaces are good emitters (of radiation) do not credit answers which infer reflection from the underside of the hood ignore correct reference to absorption 2 (ii) correct diagram drawn with one output arrow narrower than the other ignore input arrows correctly labelled with energy form eg flow charts score zero 2 (iii) energy cannot be destroyed accept (principle of) conservation of energy do not accept because energy cannot be lost without clarification 1 [9] M24. (a) 9 allow 1 mark for correct substitution (1.8 × 5) an answer of 9000 gains 1 mark an answer of 2 or 15 gains 1 mark 2 (b) (3kW) fan heater accept 3kW accept the middle one 1 (c) features common to more than one heater, treat as neutral oil-filled low level heat cannot be knocked over / space saving / no trailing wires do not accept just wall-mounted or more control over heat output do not accept just 3 heat settings 1 fan warms (office) rapidly or can be used to cool air (in summer) accept can be used as a fan accept cool air fan (setting) accept ‘it has a cool air setting in case it gets too hot’ do not accept a specific reference to cooling the heater 1 ceramic can be switched on for set periods of time do not accept just has a timer or can be switched on before office is used / switched off automatically at night 1 [6] M25. (a) 1/25 or 1:25 or 0.04 accept 4 % or marks or 1 in 25 for both allow 1 mark for total of 375 allow 1 mark for a clearly correct method using a clearly incorrect total do not accept 1:26 2 (b) (i) B do not credit reason if B is not chosen 1 (only) burning fossil fuels produces carbon dioxide / carbon (emissions) or nuclear fuels don’t produce carbon dioxide insufficient – smallest amount of fossil fuels accept less carbon dioxide 1 (ii) accept anything reasonable eg increased level of insulation use energy efficient light bulbs do not leave appliances on standby switch thermostats down (1°C) generate own electricity install solar panels accept insulate accept specific examples eg loft 1 (c) (i) any three from: • no power output until wind speed exceeds 4m/s • output rises rapidly after 4m/s • output begins to level out / rises less rapidly at / after 13m/s • output peaks at 21 / 22m/s • output constant between 21 / 22 and 25 / 26 m/s • output falls (rapidly) after 25 / 26m/s accept for 1 mark goes up then comes down 3 (ii) any one from: • unreliable energy source • dilute energy source • take up too much land accept wind does not always blow accept need thousands / lots of turbines ignore reference to visual / noise pollution ignore reference to kill birds 1 [9] M26. (a) (i) radio(waves) 1 (ii) energy correct answer only 1 (b) (i) 0.0125 (m) allow 1 mark for correct transformation and substitution 2 (ii) make it hot(ter) do not accept cook it accept (air) particles inside ball will move faster accept water in the ball gets hotter 1 (iii) wavelength decreases ignore reference to speed 1 frequency increases 1 [7] M27. (a) grid accept any unambiguous indication 1 (b) (i) A (only) 1 (ii) D (only) 1 (c) more than accept any unambiguous indication 1 [4] M28. (a) C (only) 1 (b) A (only) 1 [2] (a) reflection at the mirror of ray from tip of real puppy’s ear to real puppy’s eye (1) may be drawn freehand M29. accurate (1) ruler must have been used and the reflected ray is an extension of the straight line from point virtual ear however the virtual part of the line need not be shown arrow to show correct direction (1) only one arrow needs to be shown but there must be no contradiction example of (3) mark response 3 (b) flat accept ‘it’s not curved/bent’ accept ‘it’s straight’ 1 [4] M30. (a) electrical 1 sound correct order only 1 (b) the energy transformed by the TV will be destroyed 1 (c) a higher efficiency than 1 [4] M31. (a) (i) an unreliable energy source 1 (ii) a predictable energy source 1 (b) plant / grow (at least) one new tree 1 (c) greater than 4 % 1 [4] M32. (a) the bigger the surface area, the faster the water cools down / temperature falls answers must imply rate accept heat for temperature provided rate is implied do not accept cools down more unless qualified 1 (b) any two from: the ears: • have large surface / area not just has large ears • radiate heat accept loses heat, but does not score if the reason given for heat loss is wrong • keep blood cooler 2 (c) (i) radiation 1 (ii) conduction 1 [5] M33. (a) (i) France 1 (ii) any one from: • different homes have different appliances(*) • different homes have different numbers of appliances(*) (*) accept all homes are different • standby power not the same for all appliances • some people will switch appliances off accept named appliances accept people waste different amounts of energy • homes have different numbers of residents • can’t measure every (individual) home accept any sensible suggestions do not accept answers in terms of accurate / precise etc 1 (b) (i) increases amount of energy wasted accept (encourages) people to leave appliances on (standby) accept increases it 1 (ii) any two from: • less electricity needed / generated • fewer power stations needed • less coal is burned do not accept coal is non-renewable / running out answers in terms of fuel stocks neutral • less pollutant gases produced accept named gases accept harmful for pollutant accept greenhouse gases accept reduce / slow / stop global warming accept reduces acid rain 2 (c) joule 1 (d) (i) 6800 accept £68 for 3 marks an answer of 68 gains 2 marks allow 2 marks for correct substitution ie 400 × 17 allow 1 mark for obtaining 400 answers of 7480, 4760, 12920, 4080 gain 2 marks 3 (ii) a small . . . . . . electricity 1 [10] M34. (a) (i) compare (the health of) mobile phone users with nonmobile phone users must be an implied comparison between users and non-users any idea of doing an experiment negates the mark 1 (ii) increase the sample size accept use more people accept have a large sample size repeat the research / test is neutral 1 (iii) ethical 1 (b) (i) so the phones can be compared (fairly) a fair test is insufficient accept different tests (may) give different results do not accept to make the results reliable, unless qualified eg all variables are controlled do not accept bias unless qualified 1 (ii) yes all are below the legal limit / 2 (W/kg) or no and any one from: • even absorbing a small amount of energy may be harmful accept microwaves for energy accept emits energy absorbed by head / other parts of body • no proof that small amounts of energy are not harmful accept because the SAR value is not 0 (W/kg) 1 (c) any one from: • to get an independent opinion • company scientists may be biased accept company scientists may manipulate results 1 [6] M35. (a) (i) 0.6 accept 60 % allow 1 mark for useful energy = 480 answer 0.6 with any unit or 60 gains 1 mark only 2 (ii) transferred to surroundings accept goes into the air accept heats the surroundings up accept gets spread out accept transferred into heat (only) do not accept wasted / lost unless qualified destroyed negates mark transferred into light / sound negates mark 1 (b) (i) 1.75 allow 1 mark for converting to kW answers of 0.7, 0.525, 0.35, 0.875, 1.05, 5.25 gains 1 mark answers of 1750 or 17.5 gains 1 mark 2 (ii) 21p or £0.21 or their (b)(i) × 12 1 (c) any two from: • (more) electricity needs to be generated (more) electricity is being used • (more) power stations needed • (more) fossil fuels burnt accept named fossil fuel • (more) pollutant gases emitted accept named gas accept harmful for pollutant accept greenhouse gases accept atmospheric pollution accept answer in terms of any form of electricity generation and an associated environmental problem 2 [8] M36. (a) decrease in oil PLUS any one from: • increase in (proportion of) coal • increase in (proportion of) nuclear • increase in (proportion of) gas must have decrease in (proportion of) oil and increase in (proportion of) coal / nuclear / gas 1 (b) (i) (nuclear) fission accept fision do not accept any answer that looks like fusion 1 (ii) water heated to produce (high pressure) steam 1 steam turns turbine which drives generator 1 (iii) any two from: • produces no pollutant gases accept named gas or greenhouse gases accept no atmospheric pollution accept harmful for pollutant accept does not contribute to global warming do not accept no pollution on its own do not accept better for the environment unless qualified • it is reliable or can generate all of the time • concentrated energy source or produces a lot of energy from a small mass • produces only small volume of (solid) waste • fossil fuels will last longer accept a named fossil fuel accept fossil fuels are running out do not accept fossil fuels are nonrenewable unless qualified • will need to buy less fuel from other countries accept no new fossil fuel power stations needed do not accept it is cheap do not accept import less electricity 2 (iv) it is / can be radioactive do not accept answers in terms of kills cells / cancer or emits radiation (from the nuclei) accept emits gamma (rays) 1 (c) coal (burning) power stations / burning coal produces carbon dioxide they refers to coal-burning power stations accept sulfur dioxide / nitrogen oxides for CO2 1 (increased) CO2 increases / contributes to / causes global warming / greenhouse effect mention of ozone layer negates this mark do not accept CO2 warms atmosphere 1 [9] M37. (a) conduction do not accept conductor 1 (b) the freezer both parts needed greater temperature difference (between freezer and room) do not accept because it is the coldest 1 (c) any two from: • poor absorber of heat / radiation accept does not absorb heat poor emitter of heat / radiation is neutral • reflects heat / radiation (from room away from fridge-freezer) • reduces heat transfer into the fridge-freezer • reduces power consumption of fridge-freezer do not accept it is a bad conductor / good insulator 2 [4] M38. (a) (i) correct order essential (A =) a microphone 1 (B =) an oscilloscope or cathode ray oscilloscope or CRO 1 (ii) the amplitude accept any unambiguous indication 1 (iii) quieter / softer do not accept less (which could refer to the amplitude, frequency or wavelength) 1 (b) sound cannot travel through a vacuum / (empty) space / free space accept there is no medium for the sound to travel through 1 (because) there is / are nothing / no particles to vibrate accept (because) there is / are nothing / no particles between them and the source (of the sound) 1 [6] M39. (a) (i) plane accept any unambiguous indication 1 (ii) inverted 1 virtual accept any unambiguous indication 1 (b) reflection takes place at the surface of the pond and angle of incidence = angle of reflection as judged by eye 1 reflected ray is a straight line to frog’s eye through the air 1 correct direction arrow either from insect or to frog’s eye only one arrow essential but do not accept if either arrow contradicted example of a fully correct response 1 [6] M40. (a) the normal 1 (b) v 1 (c) any one from: • light has moved from glass to air / from air to glass accept light has changed medium • speed of light has changed beware of contradictions for this marking point eg light has moved from glass to air and slowed down gets zero • angle of incidence is less than the critical angle or (angle) i < (angle) c or (angle) y is less than the critical angle • change in density (of medium) eg glass is more (optically) dense than air 1 (d) (i) ratio of v to y does not give the same answer (in every case) or value of v doubles value of y does not double 1 or increments for v are the same but increments for y are not the same allow for 1 mark a calculation but no conclusion eg 30 → 60 19 → 35 (38) 1 (ii) as (angle) v increases, angle y increases accept as the angle of incidence increases, the angle of refraction increases or there is a (strong) positive(non-linear) relationship between the variables or ratio of sines is constant do not accept angle y is not directly proportional to angle v 1 (iii) no evidence outside this range OWTTE or when angle y is greater than the critical angle total internal reflection occurs 1 [7] M41. (a) electric drill C 1 MP3 player E 1 toaster B 1 (b) (i) 2100 no unit required / ignore units accept 2.1 kW must have units for this 1 (ii) Y 1 (iii) bar drawn with any height greater than Y ignore width of bar 1 (c) (i) any one from: answers must be a comparison • holds more water do not accept 1 litre of water on its own • works in other countries accept a named country accept works at 2 voltages • boils faster • has a more powerful element do not accept 1 kW element on its own • can filter water 1 ignore can wash filter (ii) any one from: • it weighs less • smaller to pack • cheaper to use answers must be a comparison or state why the chosen feature is an advantage accept boils enough for one drink 1 [8] M42. (a) (i) 25 (%) do not accept ¼ 1 (ii) increases 1 (b) tick ( ) in top and bottom box both required 1 (c) SHINY surfaces are good reflectors of infra-red radiation accept white for shiny or black surfaces are POOR reflectors of infra-red radiation accept bad for poor accept insertion of ‘not’ before ‘good’ in statement or black surfaces are good EMITTERS of infra-red radiation or black surfaces are good ABSORBERS of infra red radiation 1 [4] - M43. (a) any two from: • (burning) fossil fuels produces greenhouse gases / pollutant gases / acid rain / leads to global warming accept a named fossil fuel accept a named pollutant gas • nuclear fuels produce dangerous waste accept radioactive for dangerous accept reference to dangers of nuclear fuels • fossil fuels are non-renewable accept running out of fuels • renewable energy resources produce no pollutant gases • large amounts of energy are available accept renewable won’t run out • running costs are low accept any reasonable benefit of renewables accept any reasonable drawback of nonrenewables do not accept better for the environment on its own 2 (b) RUST all in correct order allow 2 marks for 2 correct allow 1 mark for one correct 3 [5] M44. (a) (i) small proportion of energy / power is wasted accept little / less energy / power / heat is wasted do not accept it wastes no energy / power or transfers most / more / a lot of energy power usefully 1 (ii) it decreases the current / uses low current or it increases the voltage / potential difference accept pd for potential difference 1 or uses high voltage / potential difference smaller the current the smaller the energy loss accept power / heat for energy 1 (b) (i) as a control accept to make a comparison do not accept fair test on its own 1 (ii) so people know how much data the link was based on accept idea that larger numbers are better or people can judge the significance / reliability of the link do not accept significance / reliability on its own ignore reference to accuracy 1 (iii) other possible factors may be responsible 1 or have not been investigated named factor eg environment / genetic 1 (iv) first box ticked plus reason acceptable reason such as so people know there may be a risk as soon as possible / so that other scientists can use findings or second box plus reason acceptable reason such as no point to worry / confuse / panic people (until the research has been confirmed) accept idea that it may lead to wrong advice do not accept in case they are wrong 1 [8] M45. (a) £15 allow 1 mark for use of 125 (kWh) allow 1 mark for an answer 1500 allow both marks for 1500 pence / p allow 1 mark for correct calculation of annual cost for either freezer (£27 and £42) 2 (b) £45 or their (a) × 3 allow 1 mark for correct use of 3 allow 1 mark for 12 – 9 = 3 2 (c) any two from: the marks are for the explanation yes plus explanation • less electricity / energy needed / used accept less energy wasted • less (fossil) fuels burned accept a named fossil fuel do not accept conserving (fossil) fuels • less polluting gases emitted accept a named polluting gas / greenhouse gases / carbon emissions / reduce global warming accept an answer in terms of nuclear fuel eg less nuclear fuel required (1) less nuclear waste (1) 2 or no plus explanation • old freezer must be disposed of • hazardous chemicals inside freezer accept CFC gases • (lot of) energy used in producing new freezer [6] M46. (a) (i) makes it warmer / raises the temperature accept produces convection (current) accept makes it less dense 1 (ii) reduced or slows down 1 (b) (i) electrical energy (to run the pump) must be paid for accept electricity for electrical energy accept electricity is needed for the pump accept it uses electricity accept because of the pump 1 (ii) more useful (heat) energy is transferred into the house than the energy used to operate the pump or reduced cost of heating the house is greater than the cost of running the (electrical) pump or costs little to run compared to the savings made accept for 1 mark reduces energy bills or reduced fuel costs / heating costs owtte do not accept it’s cheap 2 [5] M47. (a) C or 0.18 mm 1 (b) 0.6 m allow 1 mark for correct transformation and substitution allow 1 mark for changing frequency to Hz answer 600 gains 1 mark 2 (c) creates an alternating current accept ‘ac’ for alternating current accept alternating voltage 1 with the same frequency as the radio wave accept signal for radio wave or it gets hotter 1 (d) X-rays cannot penetrate the atmosphere accept atmosphere stops X-rays do not accept atmosphere in the way or X-rays are absorbed (by the atmosphere) before reaching Earth ignore explanations 1 [6] M48. (a) big bang theory – universe started at one point (then expanded) 1 steady state theory – universe has no origin / has always existed accept an answer in terms of mass eg steady state theory mass is created 1 (b) (i) wavelength (of light) increases accept answers in terms of frequency decrease accept wavelength stretched but not wave stretched or wavelength / light moves to red end of spectrum do not accept galaxy moves to the red end of the spectrum do not accept light becomes red / redder 1 (ii) red-shift is evidence / supports idea of expanding universe accept prove for support 1 both theories use the idea / accept / explain why the universe is expanding 1 (c) to find evidence to support one or both theories accept prove for support accept to gain more knowledge about the universe or to find evidence to disprove one or both theories 1 (d) answer involves (religious) belief accept it cannot be tested or no / insufficient evidence 1 [7] M49. (a) (mechanical) vibration(s) not just ‘particles knocking into each other’ not reference to ‘sound particles’ 1 (b) K 1 (c) (i) reflected by the material from loudspeaker to microphone X 1 shown by straight lines with angle of incidence = angle of reflection (by eye) and at least one arrow in the correct direction do not credit if the direction is contradicted by any incorrect arrow / may be shown by waves / wavefronts in the direction of straight lines ignore any sound to Y or which ‘misses’ the material example 1 (ii) any one from: • so (the student) can compare results • so only one (independent) variable • to get reliable / accurate results • because (the expanded) polystyrene absorbs some of the sound do not credit just ‘so it’s a fair test’ 1 (iii) [A] wood 1 [B] either 0.25 or 1/4 or 25 % or 15/60 or 1: 3 do not credit 1 : 4 1 (d) practical suggestion 1 appropriate reason / explanation example line / panel the walls with wood / plasterboard / increase the thickness of the plaster (on the walls) (1) (this) will absorb / reflect (back) (most / some of) the sound (1) credit legal suggestions for attempting to limit the noise made by the neighbours example ask the neighbours to make less noise (1) by limiting the time(s) music played (1) do not credit reference to ‘sound particles’ for second mark 1 [9] M50. (a) iron 1 hairdryer 1 kettle answers can be in any order 1 (b) sound 1 (c) is more efficient than 1 [5] M51. (a) gas 1 oil 1 (b) (both) use steam to drive a turbine accept (both) use turbines to drive generators do not accept both have a turbine /generator / use steam must describe a step in the process accept heat / thermal energy transformed to kinetic / electrical energy 1 (c) 140 (°C) correct answer only allow 1 mark for method clearly shown on graph accept a cross or other indication at correct position on the line accept correct description accept even if numerical answer is incorrect 2 (d) any one from: do not accept answers purely in terms of disadvantages of other methods except for fossil fuels are running out • very large energy source / reserves • no polluting / harmful gases produced accept named gas CO2 SO2 NOx accept reduces harmful carbon emissions • reduces carbon emissions accept does not contribute to global warming • no fuel needed • energy is free • can generate energy for a long time accept energy available for a long time • renewable (energy source) • fossil fuels are running out accept it saves fossil fuels / non-renewable accept reduces the amount of fossil fuels being burnt accept a named fossil fuel Better for the environment / environmentally friendly insufficient it is cheaper is insufficient 1 [6] M52. (a) £19.20 allow 1 mark for correct substitution ie 160 × 12 allow 1 mark for an answer (£)1920 an answer of 1920p gains both marks an answer of £40.80 gains both marks allow 1 mark for 340 × 12 2 (b) 340 allow 1 mark for correctly using the reading 62580 ie 62920 − 62580 accept £40.80 for both marks 2 [4]
