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P1.1 Energy Level 3 Questions

Q1. Figure 1 shows a graph of current against potential difference for a solar cell when light of intensity 450 W/m2 is incident on it.

(a) Determine the power output of the solar cell when the potential difference is 0.5 VUse data from Figure 1. (3)

(b) Draw a sketch graph on Figure 2 to show how the power output of the solar cell varies with potential difference between 0.1 V and 0.5 V. No values need to be included on the vertical axis.

(2)(c) The maximum power output of this solar cell is 0.52 W

When the light intensity is 450 W/m2 the cell has an efficiency of 0.15 at the maximum power output. Calculate the area of the solar cell. (4)

(d) A householder has four solar cells.Each of the solar cells has a resistance of 0.78 ΩExplain how the solar cells should be connected so that the total resistance is as low as possible. (2)

(Total 11 marks)

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Q2. A student investigated how current varies with potential difference for two different lamps. Her results are shown in the graph.

(a) Complete the circuit diagram for the circuit that the student could have used to obtain the results shown in the figure above.

(3)

(b) Which lamp will be brighter at any potential difference? Explain your answer. Use the figure above to aid your explanation (2)

(c) Lamp B has the higher resistance at any potential difference. Explain how the figure above shows this. (2)

(d) Both lamps behave like ohmic conductors through a range of values of potential difference. Use the figure above to determine the range for these lamps. Explain your answer. (3)

(Total 10 marks)

Q3. The figure below shows a student before and after a bungee jump.

The bungee cord has an unstretched length of 20.0 m.

The mass of the student is 50.0 kg.

The gravitational field strength is 9.8 N / kg.

(a) Write down the equation which links gravitational field strength, gravitational potential energy, height and mass. (1)

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(b) Calculate the change in gravitational potential energy from the position where the student jumps to the point 20.0 m below. (2)

(c) 80% of this change in gravitational potential energy has been transferred to the student’s kinetic energy store. How much has the student’s kinetic energy store increased after falling 20.0 m? (1)

(d) Calculate the speed of the student after falling 20.0 m. Give your answer to two significant figures. (4)

(e) At the lowest point in the jump, the energy stored by the stretched bungee cord is 24.5 kJ.The bungee cord behaves like a spring. Calculate the spring constant of the bungee cord.Use the correct equation from the Physics Equation Sheet. (3)

(Total 11 marks)Q4. All European Union countries are expected to generate 20% of their electricity using renewable energy sources by 2020.

The estimated cost of generating electricity in the year 2020 using different energy sources is shown in Table 1.

Energy source Estimated cost (in the year 2020) in

pence per kWhNuclear 7.8

Solar 25.3Tidal 18.8Wind 10.0

France generated 542 billion kWh of electricity using nuclear power stations in 2011.France used 478 billion kWh of electricity and sold the rest of the electricity to other countries in 2011.

(a) France may continue generating large amounts of electricity using nuclear power stations instead of using renewable energy resources. Suggest two reasons why. (2)

(b) Give two disadvantages of generating electricity using nuclear power stations. (2)

(c) A panel of solar cells has an efficiency of 0.15. The total power input to the panel of solar cells is 3.2 kW. Calculate the useful power output of this panel of solar cells in kW. (2)

(d) Table 2 shows the manufacturing cost and efficiency of different types of panels of solar cells.

Type of Solar Panel Cost to manufacture a

1 m2 solar panel in £ Efficiency in %

A 40.00 20B 22.50 15C 5.00 10

Some scientists think that having a low manufacturing cost is more important than improving the efficiency of solar cells. Use information from Table 2 to suggest why. (2)

(Total 8 marks)

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Q5. Figure 1 shows an exercise device called a chest expander. The three springs are identical.

A person pulls outwards on the handles and does work to stretch the springs.

(a) Complete the following sentence.When the springs are stretched ___________ ___________ energy is stored in the springs.

(1)(b) Figure 2 shows how the extension of

a single spring from the chest expander depends on the force acting on the spring.

(i) How can you tell, from Figure 2, that the limit of proportionality of the spring has not been exceeded? (1)

(ii) Use data from Figure 2 to calculate the spring constant of the spring.Give the unit. (3)

(iii) Three identical resistors joined in parallel in an electrical circuit share the total current in the circuit. In a similar way, the three springs in the chest expander share the total force exerted. By considering this similarity, use Figure 2 to determine the total force exerted on the chest expander when each spring is stretched by 0.25 m.

(2)

(c) The student in Figure 3 is doing an exercise called a chin-up. Each time the student does one chin-up he lifts his body 0.40 m vertically upwards.

The mass of the student is 65 kg.

The student is able to do 12 chin-ups in 60 seconds.

Calculate the power developed by the student.Gravitational field strength = 10 N/kg (3)

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(Total 10 marks)Q6. The diagram below shows a person using a device called a jetpack. Water is forced downwards from the jetpack and produces an upward force on the person.

(a) State the condition necessary for the person to be able to remain stationary in mid-air. (1)

(b) The person weighs 700 N and the jetpack weighs 140 N.(i) Calculate the combined mass of the person and the jetpack. Gravitational field

strength = 10 N/kg (2)

(ii) Increasing the upward force to 1850 N causes the person to accelerate upwards.Calculate the acceleration of the person and the jetpack. Give the unit. (3)

(Total 6 marks)

Q7. Under the same conditions, different materials heat up and cool down at different rates.

(a) What is meant by specific heat capacity? (2)

(b) ‘Quenching’ is a process used to change the properties of steel by cooling it rapidly.The steel is heated to a very high temperature and then placed in a container of cold water.(i) A metalworker quenches a steel rod by heating it to a temperature of 900 °C before

placing it in cold water. The mass of the steel rod is 20 kg.The final temperature of the rod and water is 50 °C.Calculate the energy transferred from the steel rod to the water.Specific heat capacity of steel = 420 J/kg °C.

(3)

(ii) The temperature of the steel rod eventually returns to room temperature.Compare the movement and energies of the particles in the steel rod and in the air at room temperature. (3)

(iii) When the steel rod is being quenched, the temperature of the water rises to 50 °C. After a few hours the water cools down to room temperature.Some of the cooling of the water is due to evaporation.Explain in terms of particles how evaporation causes the cooling of water. (4)

(Total 12 marks)

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Q8. Figure 1 shows the design of a playground ride.

A large wooden block rests on ropes. The ropes are attached to a metal frame.

Children sit on the wooden block.When the wooden block is moved to the left and released it moves to and fro.

When the wooden block returns to the point of release it has completed one cycle.

(a) Identify two possible hazards of the ride in Figure 1. (2)

(b) The designer of the ride wants to know if the ride has the same time period as a pendulum of the same length. The designer used a model of the ride and a pendulum as shown in Figure 2.

The designer measured the time taken to complete 10 cycles for different lengths of both the model ride and the pendulum.

The results for the model ride are shown in Table 1.

Lengthin metres

Time for 10 cycles in seconds Mean timeperiod

in secondsFirst time Second time Third time Mean

0.100 6.36 6.37 6.29 6.34 0.630.150 7.76 7.74 7.800.200 8.97 8.99 8.95 8.97 0.90

The results for the pendulum are shown in Table 2.

Lengthin metres

Time for 10 cycles in seconds Mean timeperiod

in secondsFirst time Second time Third time Mean

0.250 10.00 10.04 10.02 10.02 1.000.300 10.99 11.01 10.94 10.98 1.100.350 11.88 11.83 11.87 11.86 1.19

(i) Complete Table 1, giving values to an appropriate number of significant figures. (3)

(ii) The investigation already includes repeated readings. Suggest one improvement that could be made to this investigation. (1)

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(iii) The designer reads in an Advanced Physics textbook that:‘The square of the time period, T, for a simple pendulum is proportional to its length, l.’

T 2 ∝ l

Would the model ride have the same time period as a simple pendulum of the same length? Use one row of data from Table 1 and one row of data from Table 2 to work out your answer. State your conclusion. (3)

(c) The ride was redesigned and built to make it safer. The wood was moving at maximum speed. The maximum kinetic energy of the wood was 180 J. A parent applied a force to the wood and stopped it in a distance of 0.25 m. Calculate the force required. (3)

(Total 12 marks)

Q9. The image below shows a solar thermal power station that has been built in a hot desert.

The power station uses energy from the Sun to heat water to generate electricity.Energy from the Sun is reflected towards a solar receiver using many mirrors.

(a) (i) Which part of the electromagnetic spectrum provides most of the energy to heat the water in a solar thermal power station? (1)

(ii) Describe how heated water is used to generate electricity by thissolar thermal power station. The process is the same as in a fossil fuel power station. (3)

(b) A new type of solar power station, called a solar storage power station, is able to store energy from the Sun by heating molten chemical salts. The stored energy can be used to generate electricity at night.

(i) It is important that the molten chemical salts have a high specific heat capacity.Suggest one reason why. (1)

(ii) The solar storage power station can store a maximum of 2 200 000 kWh of energy.The solar storage power station can supply a town with a maximum electrical power of 140 000 kW.

Calculate for how many hours the energy stored by the solar storage power station can supply the town with electrical power. Give your answer to 2 significant figures.

(3)

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(iii) Table 1 gives information about the place where the solar storage power station has been built.

Season Mean number ofdaylight hours

Mean power received fromthe Sun per square metre in kW

Spring 11.5 0.90Summer 13.5 1.10Autumn 12.0 0.95Winter 10.5 0.71

The solar storage power station does not operate at the maximum possible electrical output every day of the year. Suggest why. (2)

(d) Power stations do not work at maximum possible electrical output all the time. The ‘capacity factor’ of a power station is calculated using the equation:

Table 2 shows capacity factors for different types of power station.

Type of power station Renewable energysource Capacity factor

Coal No 0.41Natural gas No 0.48Nuclear No 0.66Solar thermal Yes 0.33Tidal Yes 0.26Wind turbine Yes 0.30

(i) Compare the capacity factors of the renewable power stations with those of the non-renewable power stations in Table 2. Explain the reason for the difference between the capacity factors. (3)

(ii) The capacity factor of a solar storage power station is higher than for all other renewable power stations. Suggest one reason why. (1)

(Total 14 marks)

Q10. A ‘can-chiller’ is used to make a can of drink colder. The image shows a can-chiller.

(a) The initial temperature of the liquid in the can was 25.0

°C. The can-chiller decreased the temperature of the liquid to 20.0 °C.

The amount of energy transferred from the liquid was 6930 J. The mass of liquid in the can was 0.330 kg.Calculate the specific heat capacity of the liquid. Give the unit. (4)

(b) Energy is transferred through the metal walls of the can of drink by conduction.Explain how. (4)

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(c) The energy from the can of drink is transferred to the air around the can-chiller.A convection current is set up around the can-chiller. Explain how. (3)

(d) The can-chiller has metal cooling fins that are designed to transfer energy quickly to the surroundings. Give two features that would help the metal cooling fins to transfer energy quickly to the surroundings. (2)

(Total 13 marks)

Q11. (a) Figure 1 shows the forces acting on a model air-powered rocket just after it has been launched vertically upwards.

(i) How does the velocity of the rocket change as the rocket moves upwards? Give a reason for your answer. (2)

(ii) The velocity of the rocket is not the same as the speed of the rocket. What is the difference between the velocity of an object and the speed of an object? (1)

(b) The speed of the rocket just after being launched is 12 m / s. The mass of the rocket is 0.05 kg.

(i) Calculate the kinetic energy of the rocket just after being launched. (2)

(ii) As the rocket moves upwards, it gains gravitational potential energy. State the maximum gravitational potential energy gained by the rocket. Ignore the effect of air resistance. (1)

(iii) Calculate the maximum height the rocket will reach. Ignore the effect of air resistance. Gravitational field strength = 10 N/kg. (2)

(iv) Figure 2 shows four velocity−time graphs.

Taking air resistance into account, which graph, A, B, C or D, shows how the velocity of the rocket changes as it falls from the maximum height it reached until it just hits the ground? (1)

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(c) The rocket can be launched at different angles to the horizontal. The horizontal distance the rocket travels is called the range. Figure 3 shows the paths taken by the rocket when launched at different angles. Air resistance has been ignored.

What pattern links the angle at which the rocket is launched and the range of the rocket? (2)

(Total 11 marks)

Q12. Table 1 shows information about different light bulbs. The bulbs all have the same brightness.

Type of bulb Input power in watts EfficiencyHalogen 40 0.15Compact fluorescent (CFL) 14 0.42LED 7 0.85

(a) (i) Calculate the useful power output of the CFL bulb. (2)

(ii) Use your answer to part (i) to calculate the waste energy produced each second by a CFL bulb. (1)

(b) (i) A growth cabinet is used to investigate the effect of light on the rate of growth of plants.

In the cabinet the factors that affect growth can be controlled. A cooler unit is used to keep the temperature in the cabinet constant. The cooler unit is programmed to operate when the temperature rises above 20 °C. The growth cabinet is lit using 50 halogen bulbs. Changing from using halogen bulbs to LED bulbs would reduce the cost of running the growth cabinet.Explain why. (4)

(ii) A scientist measured the rate of growth of plants for different intensities of light.What type of graph should be drawn to present the results? Give a reason for your answer. (1)

(c) Table 2 gives further information about both a halogen bulb and a LED bulb.

Type of bulb

Cost to buy

Lifetime in hours

Operating cost over the lifetime of one bulb

Halogen £1.50 2 000 £16.00LED £30.00 48 000 £67.20

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A householder needs to replace a broken halogen light bulb. Compare the cost efficiency of buying and using halogen bulbs rather than a LED bulb over a time span of 48 000 hours of use. Your comparison must include calculations. (4)

(Total 12 marks)

Q13. Solar panels are often seen on the roofs of houses.(a) Describe the action and purpose of a solar panel. (2)

(b) Photovoltaic cells transfer light energy to electrical energy. In the UK, some householders have fitted modules containing photovoltaic cells on the roofs of their houses. Four modules are shown in the diagram.

The electricity company pays the householder for the energy transferred. The maximum power available from the photovoltaic cells shown in the diagram is 1.4 × 103 W. How long, in minutes, does it take to transfer 168 kJ of energy? (3)

(c) When the modules are fitted on a roof, the householder gets an extra electricity meter to measure the amount of energy transferred by the photovoltaic cells.

(i) The diagram shows two readings of this electricity meter taken three months apart.The readings are in kilowatt-hours (kWh).

21 November 0 0 0 4 4

21 February 0 0 1 9 4

Calculate the energy transferred by the photovoltaic cells during this time period. (1)

(ii) The electricity company pays 40p for each kWh of energy transferred. Calculate the money the electricity company would pay the householder. (2)

(iii) The cost of the four modules is £6000. Calculate the payback time in years for the modules. (3)

(iv) State an assumption you have made in your calculation in part (iii). (1)

(d) In the northern hemisphere, the modules should always face south for the maximum transfer of energy. State one other factor that would affect the amount of energy transferred during daylight hours. (1)

(Total 13 marks)

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Q14. An electric immersion heater is used to heat the water in a domestic hot water tank.

When the immersion heater is switched on the water at the bottom of the tank gets hot.

(a) Complete the following sentence. The main way the energy is transferred through the copper wall of the water tank is by the process of …..

(1)(b) The immersion heater has a thermostat to control the water temperature.

When the temperature of the water inside the tank reaches 58°C the thermostat switches the heater off. The thermostat switches the heater back on when the temperature of the water falls to 50°C.

Graph A shows how the temperature of the water inside a hot water tank changes with time. The tank is not insulated.

Time in hours

(i) The temperature of the water falls at the fastest rate just after the heater switches off. Explain why. (2)

(ii) To heat the water in the tank from 50°C to 58°C the immersion heater transfers 4032 kJ of energy to the water. Calculate the mass of water in the tank. Specific heat capacity of water = 4200 J/kg°C (3)

(iii) An insulating jacket is fitted to the hot water tank. Graph B shows how the temperature of the water inside the insulated hot water tank changes with time.

Time in hours

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An insulating jacket only costs £12. By comparing Graph A with Graph B, explain why fitting an insulating jacket to a hot water tank saves money. (3)

(Total 9 marks)Q15. (a) In the UK, over 70% of the electricity is generated in power stations that burn fossil fuels.

(i) Explain one effect that burning fossil fuels has on the environment. (2)

(ii) Give one way the effect on the environment described in part (a)(i) could be reduced. Assume the amount of fossil fuels burnt stays the same. (1)

(b) Electricity can also be generated in a pumped storage hydroelectric power station.An advantage of pumped storage hydroelectric power stations is the short start-up time they have.

(i) What is the importance of the short start-up time? (1)

(ii) Give one other advantage of a pumped storage hydroelectric power station. (1)

(c) Read the extract below from a newspaper article.

(i) In the UK, the proportion of electricity generated using wind turbines is due to

increase a lot. Some opponents of wind turbines think this increase will cause big fluctuations in the electricity supply. Suggest one reason why this may be true. (1)

(ii) Between 2002 and 2008 the amount of electricity used for lighting in homes in the UK decreased. Suggest one reason why. (1)

(Total 7 marks)

Q16. About half of the UK’s electricity is generated in coal-burning power stations and nuclear power stations.

(a) Coal-burning power stations and nuclear power stations provide a reliable way of generating electricity. What is meant by a reliable way of generating electricity? (1)

(b) Over the next few years, most of the older nuclear power stations in the UK will be closed down, and the process of decommissioning will start. What does it mean to decommission a nuclear power station? (1)

(c) Climate change has been strongly linked to the emission of carbon dioxide. Many governments around the world are committed to reducing carbon dioxide emissions.Generating electricity can increase carbon dioxide emissions. The companies generating electricity could reduce carbon dioxide emissions. Give two ways the companies could do this. (2)

(d) Electricity is distributed from power stations to consumers along the National Grid.The voltage across the overhead cables of the National Grid needs to be much higher than the output voltage from the power station generators. Explain why. (3)

(Total 7 marks)

Q17. (a) Solar energy is a renewable energy source used to generate electricity.(i) What is meant by an energy source being renewable? (1)

(ii) Name two other renewable energy sources used to generate electricity. (1)

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(b) A householder uses panels of solar cells to generate electricity for his home.The solar cells are tilted to receive the maximum energy input from the Sun.

The data in the table gives the average energy input each second (in J/s), to a 1 m2 area of solar cells for different angles of tilt and different months of the year.

Month Angle of tilt20° 30° 40° 50°

February 460 500 480 440April 600 620 610 600June 710 720 680 640

August 640 660 640 580October 480 520 500 460

December 400 440 420 410

(i) Use the data in the table to describe how the average energy input to the solar cells depends on the angle of tilt. (2)

(ii) The total area of the solar cell panels used by the householder is 5 m2.The efficiency of the solar cells is 0.18. Calculate the average maximum electrical energy available from the solar cell panels each second in June. Show clearly how you work out your answer. (3)

(c) The diagram shows part of the National Grid.

(i) Even though the householder uses solar cells to generate electricity for his home, the home stays connected to the National Grid. Give one reason why the householder should stay connected to the National Grid. (1)

(ii) The step-up transformer increases the efficiency of the National Grid. Explain how. (2)

(Total 10 marks)

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Q18.The table gives data about two types of low energy bulb.

Type of bulb Power inputin watts

Efficiency Lifetimein hours

Cost ofone bulb

Compact FluorescentLamp (CFL) 8 20% 10 000 £3.10

Light Emitting Diode(LED) 5 50 000 £29.85

(a) Both types of bulb produce the same useful power output.

(i) Calculate the useful power output of the CFL. Show clearly how you work out your answer. (2)

(ii) Calculate the efficiency of the LED bulb. Show clearly how you work out your answer. (1)

(b) LED bulbs are expensive. This is because of the large number of individual electronic LED chips needed to produce sufficient light from each bulb.

(i) Use the data in the table to evaluate the cost-effectiveness of an LED bulb compared to a CFL. (2)

(ii) Scientists are developing brighter and more efficient LED chips than those currently used in LED bulbs. Suggest one benefit of developing brighter and more efficient LED chips. (1)

(Total 6 marks)Q19. (a) Nuclear fuels and the wind are two of the energy sources used to generate electricity in the

UK.

Explain the advantages of using energy from nuclear fuels to generate electricity rather than using energy from the wind. Include in your answer a brief description of the process used to generate electricity from nuclear fuels. (4)

(b) In the UK, most electricity is generated in power stations that emit carbon dioxide into the atmosphere. The impact of these power stations on the environment could be reduced by the increased use of 'carbon capture' technology. Describe how 'carbon capture' would prevent the build-up of carbon dioxide in the atmosphere. (2)

(Total 6 marks)

Q20. The world’s biggest offshore wind farm, built off the Kent coast, started generating electricity in September 2010.

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(a) The graph shows how wind speed affects the power output from one of the wind turbines. In one 4-hour period, the wind turbine transfers 5600 kilowatt-hours of electrical energy.

Use the data in the graph to calculate the average wind speed during this 4-hour period.Show clearly how you work out your answer. (3)

(b) The wind turbines are linked to the National Grid by underwater cables.(i) What is the National Grid? (1)

(ii) How is the National Grid designed to reduce energy losses during transmission? (1)

(c) Read this extract from a newspaper.

Explain one way in which the islanders could try to ensure that a similar power crisis does not happen in the future. (2)

(Total 7 marks)

Q21. The miners working in a salt mine use smooth wooden slides to move quickly from one level to another.

(a) A miner of mass 90 kg travels down the slide. Calculate the change in gravitational potential energy of the miner when he moves 15 m vertically downwards. Gravitational field strength = 10 N/kg Show clearly how you work out your answer. (2)

(b) Calculate the maximum possible speed that the miner could reach at the bottom of the slide. Show clearly how you work out your answer. Give your answer to an appropriate number of significant figures. (3)

(c) The speed of the miner at the bottom of the slide is much less than the calculated maximum possible speed. Explain why. (3)

(Total 8 marks)

Q22. A homeowner had a new gas boiler installed.(a) The following information is an extract from the information booklet supplied with the

boiler.

Fuel Natural Gas

Water temperature 60 °CEnergy supplied to gas boiler 8.0 kJ/s (8.0 kW)

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Efficiency 0.95(i) Calculate the energy transferred each second by the gas boiler to the water inside

the boiler. Show clearly how you work out your answer. (2)

(ii) The energy value of the gas used in a home is measured in kilowatt-hours (kWh).The homeowner has a pre-payment meter and pays £30 into his account. With a pre-payment meter, gas costs 15p per kilowatt-hour. Calculate the total number of hours that the gas boiler would operate for £30. (2)

(b) Although the gas boiler is very efficient, some energy is wasted. Explain what happens to the waste energy. (2)

(Total 6 marks)

Q23. The diagram shows a small-scale, micro-hydroelectricity generator which uses the energy of falling river water to generate electricity. The water causes a device, called an Archimedean screw, to rotate.The Archimedean screw is linked to the generator by a gearbox.

(a) Each second, the micro-hydroelectricity generator transforms 80 000 joules of gravitational potential energy into 60 000 joules of electrical energy.

(i) Fill in the missing word to complete the energy transformation diagram.

Gravitational potentialenergy of the falling water

________________ energy

of the Archimedean screw

Electrical energygenerated

(1)(ii) Calculate the efficiency of the micro-hydroelectricity generator. (2)

(b) The power output from a conventional large-scale hydroelectric power station is 100 000 times more than the power output from a micro-hydroelectric system. Give one disadvantage of a conventional large-scale hydroelectric power station compared to the micro-hydroelectric system. (1)

(c) The electricity generated by a micro-hydroelectric system is transferred via a transformer directly to local homes. The electricity generated by a conventional large-scale hydroelectric power station is transferred to the National Grid, which distributes the electricity to homes anywhere in the country.

(i) What is the National Grid? (1)

(ii) Explain why transferring the electricity directly to local homes is more efficient than using the National Grid to distribute the electricity. (2)

(Total 7 marks)

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Q24. The diagram shows a wind turbine.

(a) The blades of the turbine are 20 metres long. On average, 15 000 kg of air, moving at a speed of 12 m/s, hit the blades every second. Calculate the kinetic energy of the air hitting the blades every second. (2)

(b) Part of the kinetic energy of the wind is transformed into electrical energy.The diagram shows that, for the same wind speed, the power output of a turbine, in kilowatts, depends on the length of the turbine blades.

Give a reason why doubling the diameter of the blades more than doubles the power output of a turbine. (1)

(Total 3 marks)

Q25. (a) The diagram shows a solar powered device being used to recharge a mobile phone.

On average, the solar cells produce 0.6 joules of electrical energy each second.The solar cells have an efficiency of 0.15.

(i) Calculate the average energy input each second to the device. Show clearly how you work out your answer. (2)

(ii) Draw a labelled Sankey diagram for the solar cells. The diagram does not need to be drawn to scale. (1)

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(b) Scientists have developed a new type of solar cell with an efficiency of over 40 %. The efficiency of the solar cell was confirmed independently by other scientists. Suggest why it was important to confirm the efficiency independently. (1)

(c) The electricity used in homes in the UK is normally generated in a fossil fuel power station. Outline some of the advantages of using solar cells to generate this electricity. (2)

(Total 6 marks)

Q26. Over the next 15 years, some of the older nuclear power stations will be closed down, and the process of decommissioning will start. In the same period, several countries plan to build a number of new nuclear power stations.

(a) (i) What does it mean to decommission a nuclear power station? (1)

(ii) How does decommissioning affect the overall cost of electricity generated using nuclear fuels? (1)

(b) Uranium is a fuel used in nuclear power stations to generate electricity.Graph 1 compares how the electricity generated from one kilogram of nuclear fuel changed between 1980 and 2005 in three different types of nuclear power station.

(i) Compare the efficiency of the three types of power station, K, L and M, between 1980 and 2005. (2)

Graph 2 shows two different predictions for the global growth in uranium demand over the next few years.

(ii) Suggest reasons why it is not possible to predict accurately how much uranium will

be needed in 2025. (2)(Total 6 marks)

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Q27. The farmers in a village in India use solar powered water pumps to irrigate the fields.

On average, a one square metre panel of solar cells receives 5 kWh of energy from the Sun each day.The solar cells have an efficiency of 0.15

(a) (i) Calculate the electrical energy available from a one square metre panel of solar cells. Show clearly how you work out your answer. (2)

(ii) On average, each solar water pump uses 1.5 kWh of energy each day. Calculate the area of solar cells required by one solar water pump. (1)

(b) Give one reason why the area of solar cells needed will probably be greater than the answer to part (a)(ii). (1)

(Total 4 marks)

Q28. The map shows the positions of two towns on either side of a very large coastal bay in England. The map also shows where a bridge may be built to link the towns. The road journey from one town to the other is about 60 kilometres at present.

(a) It is estimated that building turbines and generators inside the legs of the bridge would produce enough electricity for both towns. In addition, enough electricity would be generated to run electric buses over the bridge between the two towns.

(i) If the bridge is built, what form of renewable energy will be used to generate the electricity? (1)

(ii) Most people living in the area are in favour of the proposed bridge. Suggest three reasons why people would be in favour of building the bridge and the associated electricity generating scheme. (3)

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(b) Even with the proposed bridge, the two towns will need to stay connected to the National Grid. The diagram shows part of the National Grid.

(i) Give one reason why the towns need to stay connected to the National Grid. (1)

(ii) Explain how the step-up transformer increases the efficiency of the National Grid. (2)(Total 7 marks)

Q29. 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. (2)

(iv) Nuclear power stations create dangerous waste. Why is the waste from a nuclear power station dangerous? (1)

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(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)

Q30. (a) Solar energy is a renewable energy source that can be used to generate electricity.

(i) What is meant by an energy source being renewable? (1)

(ii) Name two further renewable energy sources used to generate electricity. (1)

(b) A householder uses a bank of solar cells to generate electricity for his home.

The solar cells are tilted to receive the maximum energy input from the Sun.

The data in the table gives the average energy input each second (in J/s), to a 1 m2 area of solar cells for different angles of tilt and different months of the year.

Month Angle of tilt20° 30° 40° 50°

February 460 500 480 440April 600 620 610 600June 710 720 680 640August 640 660 640 580October 480 520 500 460December 400 440 420 410

(i) Use the data in the table to describe how the average energy input to the solar cells depends on the angle of tilt. (2)

(ii) The bank of solar cells used by the householder has an area of 8 m2. The efficiency of the solar cells is 0.15 Calculate the average maximum electrical energy available from the bank of solar cells each second in June. Show clearly how you work out your answer. (3)

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(c) The graph shows how the householder’s electrical energy needs change over one year.

Why would it be advisable for the householder to remain connected to the National Grid?

(1)(Total 8 marks)

Q31. (a) The diagram shows how much heat is lost each second from different parts of an uninsulated house.

(i) Each year, the house costs £760 to heat. How much money is being wasted because of heat lost through the roof? (2)

(ii) Insulating the loft would cut the heat lost through the roof by 50 . The loft

insulation has a payback time of years. How much did the loft insulation cost to buy? (1)

(b) What happens to the wasted energy? (1)(Total 4 marks)

Q32. There is an increasing demand for electricity and the reserve of fossil fuels is decreasing. A way to meet increasing demand for electricity is to build new nuclear power stations. Some people feel that no new nuclear power stations should be built because of the risks associated with nuclear fuels.

(a) Outline the arguments that a scientist working in the nuclear power industry could use to justify the building of more nuclear power stations in the future. (3)

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(b) Nuclear waste is a problem that must be dealt with. One possible solution would be to bury the waste deep underground. Suggest one reason why some people are against burying nuclear waste. (1)

(c) Electricity can also be generated using renewable energy sources.Look at this information from a newspaper report.

• The energy from burning bio-fuels, such as woodchip and straw, can be used to generate electricity.• Plants for bio-fuels use up carbon dioxide as they grow.• Farmers get grants to grow plants for bio-fuels.• Electricity generated from bio-fuels can be sold at a higher price than electricity generated from burning fossil fuels.• Growing plants for bio-fuels offers new opportunities for rural communities.

Suggest why, apart from the declining reserves of fossil fuels, power companies should use more bio-fuels and less fossil fuels to generate electricity. (3)

(Total 7 marks)

Q33. The diagram shows how electricity is distributed from power stations to consumers.

(a) (i) What name is given to the network of cables and transformers that links power stations to consumers? (1)

(ii) What does a step-up transformer do? (1)

(iii) Explain why step-up transformers are used in the electricity distribution system. (2)

(b) Most of the world’s electricity is generated in power stations that burn fossil fuels. State one environmental problem that burning fossil fuels produces. (1)

(c) Electricity can be generated using energy from the wind. A company wants to build a new wind farm. Not everyone thinks that this is a good idea.

(i) What arguments could the company give to persuade people that a wind farm is a good idea? (2)

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(ii) What reasons may be given by the people who think that wind farms are not a good idea? (2)

(Total 9 marks)

Q34. (a) The table gives information about some ways of reducing the energy consumption in a house.

Method of reducing energy consumption

Installation cost in £

Annual saving on energy bills in £

Fit a new hot water boiler 1800 200Fit a solar water heater 2400 100Fit under floor heating 600 50Fit thermostatic radiator valves 75 20

Which way of reducing energy consumption is most cost effective over a 10-year period?To obtain full marks you must support your answer with calculations. (3)

(b) Explain why using an energy-efficient light bulb instead of an ordinary light bulb reduces the amount of carbon dioxide emitted into the atmosphere. (2)

(Total 5 marks)

Q35. (a) Explain how energy is produced in the Sun. (3)

(b) Read the following article that appeared in a magazine.

“Conservation of energy is important in today’s society. Energy sources, such as oil and coal, which have been used for the development of an industrial society, cannot be relied upon as heavily in the future. Renewable energy sources cannot provide such large quantities of energy for society without causing problems.”

(i) Give two reasons why oil should not be relied on as a major source of energy for the future. (2)

(ii) Energy from the wind is a renewable energy resource. State three problems which may arise if the wind were to be used to meet the energy requirements of a large industrial city in Britain. (3)

(Total 8 marks)

Q36. (a) Most electricity in Britain is generated by coal fired power stations.

Complete the sequence of useful energy transfers which take place in the power station. (1)

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(b) The diagram shows a wind turbine which is used to produce electricity using energy from the wind.

(i) What is the source of energy which creates winds? (1)

(ii) Explain the advantage of using a wind turbine to produce electricity. (2)(Total 4 marks)

Q37. The map shows an industrial region (shaded).

The prevailing wind is from the west. There is a nearby mountainous area, from which a river flows through the region. The major road and rail links are shown.

A power station is to be built to supply electrical energy to the region. The energy will be for a range of domestic and industrial uses.

The choice is between a coal fired power station, wind turbines and a hydroelectric scheme.

Three local groups each support a different option. Choose which option you would support and justify your choice by making reference to the financial, social and environmental implications of your choice compared with those of the alternative systems.

(Total 8 marks)

Q38. The outline diagram below shows a tidal power generating system.

Gates in the barrage are open when the tide is coming in and the basin is filling to the high tide level. The gates are then closed as the tide begins to fall.Once the tide outside the barrage has dropped the water can flow through large turbines in the barrage which drive generators to produce electrical energy.

In one second 1.2 × 109 kg of water flows through the turbines at a speed of 20 m/s.

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(a) When used with a water speed of 20 m/s the system has an efficiency of 90% in converting the kinetic energy of the water into electrical energy. Calculate the power output of the generators. (2)

(b) The power output of a coal fired power station is 1000 MW (1 x 109 W).

(i) Suggest two advantages of coal fired power stations over tidal power generating systems. (2)

(ii) Suggest two advantages of tidal power generating systems over coal fired power stations. (2)

(iii) Suggest and explain one disadvantage of a tidal power generating system. (2)(Total 8 marks)

Q39. Describe, in as much detail as you can, how the energy stored in coal is transferred into electrical energy in a power station.

(Total 5 marks)

Q40.

Transformer A produces a very high voltage to transmit the electrical energy through the National Grid. Explain why electrical energy is transmitted at a very high voltage.

(Total 3 marks)

Q41. The diagram below shows four stages in the production of electricity by a coal-fired power station.

(a) (i) Write down two environmental problems which are caused by burning coal to generate electricity. (2)

(ii) How may these environmental problems be reduced? (2)

(b) Some data for Didcot coal-fired power station is given below.

Number of generators 4Maximum continuous power rating of a generator 500 MW at 23 500 VEnergy content of coal used 2.66 × 1010 J per tonneTotal quantity of coal used each day 18 289 tonnes

Use the given data to calculate:

(i) the total electrical energy output each day. (ii) the total input of coal energy each day. (iii) the efficiency of the power station.

(8)

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(c) Energy is conserved.

(i) Choose one of the stages in the diagram at the start of the question. State what happens to the wasted energy during this stage.

(ii) Explain what happens to all wasted energy during energy transfers. (3)

(Total 15 marks)

Q42. (a) When an object is moving it is said to have momentum. Define momentum. (1)

(b) The diagram below shows one way of measuring the velocity of a bullet.

A bullet is fired into a block of wood suspended by a long thread.The bullet stops in the wooden block.The impact of the bullet makes the block swing.

The velocity of the wooden block can be calculated from the distance it swings.

In one such experiment the block of wood and bullet had a velocity of 2 m/s immediately after impact.

The mass of the bullet was 20 g and the mass of the wooden block 3.980 kg.

(i) Calculate the combined mass of the block of wood and bullet. (1)

(ii) Calculate the momentum of the block of wood and bullet immediately after impact. (3)

(iii) State the momentum of the bullet immediately before impact. (1)

(iv) Calculate the velocity of the bullet before impact. (3)

(v) Calculate the kinetic energy of the block of wood and bullet immediately after impact. (3)

(vi) The kinetic energy of the bullet before the impact was 1600 joules. This is much greater than the kinetic energy of the bullet and block just after the impact. What has happened to the rest of the energy? (1)

(Total 13 marks)

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Q43. The map below shows the position of two towns, A and B, on the banks of a large river estuary.

A is an important fishing and ferry port.The wind usually blows from the west. The major roads and railways are shown.

A power station is to be built in area X to generate electricity for the region.The choice is between a nuclear power station and a coal fired power station.

(a) State the advantages and disadvantages of the two methods of generating electrical energy. (6)

(b) Which method would you choose for this site? Explain the reason for your choice. (3)(Total 9 marks)

Q44. Use of renewable sources of energy is expected to increase. The table shows the comparative costs of producing 1 kWh of electricity from different energy sources.

Types of energy sources used

in the UKCost of producing 1 kWh of

electrical energyFossil fuels(non-renewable) Coal 1.0 p

Gas 1.4 pOil 1.5 p

Nuclear fuels (non-renewable) Nuclear 0.9 pRenewable Hydroelectric 0.2 p

Wind 0.9 pInstallation and decommissioning costs are not included

At present about 2% of electricity generated in the UK uses renewable energy sources. Consider the three types of energy sources in the table and give one advantage and one disadvantage for each (other than installation and decommissioning costs).

- Using Fossil Fuels- Using Nuclear Fuels- Using Renewable Sources

(Total 6 marks)

Q45. Different energy sources are shown in the box.

An ‘Eco-home’ is one which is friendly to the environment.Imagine you are designing an ‘Eco-home’ which can use any of the energy sources above to generate electricity

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(a) Choose one non-renewable energy source from the box above that could provide the electricity supply to your ‘Eco-home’, but which would be unsuitable. Write the energy source and explain, as fully as you can, why it is unsuitable for an ‘Eco-home’. (2)

(b) Choose two suitable renewable energy sources from the box opposite that could provide an electricity supply to your ‘Eco-home’. Write the two energy sources and describe, in as much detail as you can, the undesirable environmental effects of using these. (4)

(Total 6 marks)

Q46. The bar chart shows the relative costs of some different energy sources that are used to generate electricity.

(a) Apart from cost, give two advantages that a hydroelectric power station has compared with a wind farm. (2)

(b) Apart from cost, give one advantage and one disadvantage that a nuclear power station has compared with a coal-fired power station. (2)

(c) State and explain one situation where it is better to use solar energy, rather than any of the other energy sources, to generate electricity. (2)

(Total 6 marks)

Q47. When a gun is fired, a very large force acts on the bullet for a very short time. The change in momentum of the bullet is given by the following relationship:

force (N) × time(s) = change in momentum (kg m/s)

(a) An average force of 4000 newton acts for 0.01 seconds on a bullet of mass 50g. Calculate the speed of the bullet. (Show your working.) (4)

(b) The bullet is fired horizontally. In the short time it takes for the bullet to reach its target, its horizontal speed has fallen to 80% of its initial speed.

(i) Explain why the speed of the bullet decreases so quickly. (2)

(ii) Calculate the percentage of its original kinetic energy the bullet still has when it reaches its target. (Show your working.) (4)

(Total 10 marks)

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Q48. Antarctica is a huge land mass surrounding the Earth’s south pole. It is covered in a very thick layer of ice and is the only remaining large area of the Earth’s surface that has not been affected very much by humans.

There are, however, teams of scientists from various countries studying Antarctica. These scientists need electricity for lighting, for their computers and other scientific instruments and to communicate, via satellite, with the rest of the world. The temperature in Antarctica is always sub-zero, so the scientists need some way of keeping their buildings warm. They also need fuel to be able to get around on their snowmobiles.

Scientists cannot avoid affecting the environment. However, they want to affect it as little as possible.

Atmospheric pollution produced in one country eventually affects the whole of the Earth’s atmosphere. The hole that appears each year in the ozone layer above Antarctica, for example, is mainly caused by pollutants such as CFCs from countries in the northern half of the Earth.Discuss the advantages and disadvantages of using the following energy sources to meet the scientists’ needs:• solar energy• energy from the wind• natural gas (present in large quantities deep down in the Antarctic land mass)• diesel oil (which would have to be imported)_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(Total 10 marks)

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Mark schemesQ1.

(a) current at 0.5 V = 0.91 (A)1

P = 0.91 × 0.51

P = 0.455 (W)an answer of 0.455 (W) scores 3 marks

1(b) straight line with positive gradient

allow for 1 mark a straight line that passes through (0.1, 0)

1positive y-axis intercept

ignore any values on y-axis1

(c) 1

total P = 3.47 (W)1

1

area = 7.7 × 10–3 (m2)an answer of 7.7 × 10–3 (m2) scores 4 marksallow use of student’s calculated incorrect total power for last 2 marking points

1(d) connect the solar cells in parallel

1(so that) the current has multiple paths it can takeorthe total resistance is less than the resistance of one solar cell

1[11]

Q2.(a)

battery in series with bulb and ammeter

1voltmeter in parallel with bulb

1variable resistororvariable power packor

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potentiometer1

(b) A is brighter because it has a higher current (than lamp B at any p.d.)1

(therefore A has a) higher power output (than bulb B)accept higher energy output per second

1(c) lower current (than lamp A) for the same potential difference

accept answer in terms of R = V / I1

lower gradient (than lamp A)1

(d) 0 – 2 Voltsallow a range from 0 V up to any value between 1 and 2 V.

1(for an ohmic conductor) current is directly proportional to potential difference

allow lines (of best fit) are straight and pass through the origin

1(so) resistance is constant

1[10]

Q3.(a) g.p.e. = mass × gravitational field strength × height

accept Ep = mgh1

(b) Ep = 50 × 9.8 × 201

9800 (J)allow 9800 (J) with no working shown for 2 marksanswer may also be correctly calculated using W = Fsie allow W = 490 × 20 for 1 markor answer of 9800 (J) using this method for 2 marks

1(c) 7840 (J)

allow ecf from ‘11.2’1

(d) 7840 = ½ × 50 × v2

1

allow for this point1

17.7(0875) (m / s)1

18 (m / s)allow ecf from ‘11.3’ correctly calculated for 3 marksallow 18 (m / s) with no working for 2 marksanswer may also be correctly calculated using v2 – u2 = 2as

1(e) extension = 35 (m) and conversion of 24.5 kJ to 24500 J

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124 500 = ½ × k × 352

140

1allow 40 with no working shown for 3 marksan answer of ‘16.2’ gains 2 marks

[11]Q4.

(a) any two from:• cost per kWh is lower (than all other energy resources)

allow it is cheaperignore fuel costignore energy released per kg of nuclear fuel

• infrastructure for nuclear power already existsaccept cost of setting up renewable energy resources is highaccept many renewable power stations would be needed to replace one nuclear power stationaccept (France in 2011 already had a) surplus of nuclear energy, so less need to develop more renewable capacity for increased demand in the futureaccept France benefits economically from selling electricity

• more reliable (than renewable energy resources)accept (nuclear) fuel is readily availableignore destruction of habitats for renewables

2(b) any two from:

• non-renewableallow nuclear fuel is running out

• high decommissioning costsaccept high commissioning costs

• produces radioactive / nuclear wasteallow waste has a long half-life

• long start-up time• nuclear accidents have widespread implications

allow for nuclear accident a named nuclear accidenteg Fukushima, Chernobylignore visual pollution

2(c) 0.48 (kW)

allow 1 mark for correct substitutionie 0.15 = P / 3.2an answer of 480 W gains 2 marksan answer of 48 or 480 scores 1 mark

2(d) the higher the efficiency, the higher the cost (per m2 to manufacture)

accept a specific numerical example1

more electricity could be generated for the same (manufacturing) cost using lower efficiency solar panelsor(reducing the cost) allows more solar panels to be bought

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accept a specific numerical example1

[8]Q5.

(a) elastic potential1

(b) (i) line is straightaccept line does not curve

1(ii) 400

allow 1 mark for correct substitution of any pair of numbers correctly taken from the graph e.g.160 = k × 0.40

2newtons per metre or N/m

if symbols are used they must be correct1

(iii) 300allow 1 mark for correctly obtaining force on 1 spring = 100N

2(c) 52

allow 2 marks for calculating change in gpe for 1 chin-up as 260 (J) or for 12 chin-ups as 3120 (J)an answer 4.3 gains 2 marksallow 1 mark for correct substitution into gpe equation ie gpe = 65 × 10 × 0.4 (× 12)orcorrect use of power equation with an incorrect value for energy transferred

3[10]

Q6.(a) resultant force = zero

orupward force = downward force

accept forces are balancedaccept weight for downward force

1(b) (i) 84

allow 1 mark for correct substitution ie 840 = m × 10

2(ii) 12

accept 12.02 for both marksor1010 ÷ their (b)(i) correctly calculated

a resultant force of 1010 (N) gains 1 markan answer 22(.02) gains 1 mark

2m/s2

accept m/s/s1

[6]Q7.

(a) energy required to raise the temperature of a substance by 1 °C

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accept heat for energy1

unit mass / 1 kg1

(b) (i) 7 140 000 (J)allow 2 marks for a correct substitution, ieE = 20 × 420 × 850provided no subsequent step850 gains 1 mark if no other mark awarded

3(ii) particles in the air have more (kinetic) energy than the particles

in the steelallow particles in the air have a greater speed.

1steelparticles vibrate (about fixed positions)

1airparticles move freely

1(ii) the most energetic particles

accept molecules for particles throughoutaccept the fastest particles

1have enough energy to escape from (the surface of) the water

1therefore the mean energy of the remaining particles decreases

accept speed for energy1

as energy decreased, temperature has decreased1

[12]Q8.

(a) any two from:• wood falls off ropes• child falls off• wood hits child standing at side.

accept any reasonable suggestion2

(b) (i) 7.771

0.780.777 or 0.77 gain 1 marktheir mean value / 10 gains 1 mark

2(ii) use longer lengths (so longer times)

ordo both with the same lengths (so comparison can be made)

timing more than 10 cycles is insufficient1

(iii) 1 value of k from table 4k values 3.969… 4.056… 4.05

k =T2 / lallow full credit for an equivalent correct methodeg. allow inverse of

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k = l / T2 = 0.251

1 value of k from table 5k values 4 4.03… 4.046

allow if average time for 10 cycles used1

conclusion that matches student’s results1

(c) 720 N180 = F × 0.25 gains 2 markswork done = maximum kinetic energy gains 1 mark

3[12]

Q9.(a) (i) infrared (radiation)

accept IR (radiation)1

(ii) (heated) water turns to steamignore reference to fossil fuelsdo not accept water evaporates to steam

1steam turns a turbine

1turbine turns a generator

accept turbine connected to a generator1

(b) (i) (so the molten salts) can store large amounts of energyaccept there is a small temperature change for a large energy transferaccept heat for energy

1(ii) 16 (hours)

an answer that rounds to 16 gains 2 marks eg 15.71allow 1 mark for a correct substitution ie 2 200 000 = 140 000 × t

3(iii) the number of daylight hours varies

less sunlight is insufficient1

the (mean) power (received from the Sun per square metre) varies

accept an answer in terms of maximum possible electrical output only possible during Summer for 1 mark

1(c) (i) non-renewable power stations have higher Capacity Factors

than renewable power stations1

fuel (for non-renewable power stations) is always availablereference to non-renewable power stations operating all the time is insufficient non-renewable energy sources are reliable is insufficient

1

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(most) renewable energy sources are unpredictable / unreliableaccept (most) renewable energy sources depend on the weather

1(ii) the (proportion of) time that solar storage power stations can

generate electricity is greater (than for other renewable energy sources)

1[14]

Q10.(a) 4200

allow 2 marks for correct substitution ie 6930 = 0.330 × c × 5.0answers of 1050 or 840orcorrectly calculated answer from correct substitution of incorrect temperature changeoridentification of temperature change ie 5 °C gain 1 mark

3J / kg°C

accept J / kg K1

(b) (in a metal) free electronsto gain full credit the answer must be in terms of free electrons

1gain kinetic energy

accept move faster1

(free electrons) transfer energy to other electrons / ions / atomsdo not accept particles

1by collision

allow a maximum of 2 marks for answers in terms of atoms / ions / particles• gaining kinetic energy or vibrating faster / more• transferring energy by collisions

1(c) (air) particles spread out

1(which causes the) air to become less dense / expand

do not accept particles become less dense1

(so the) warm air risesdo not accept heat rises particles rise is insufficient

1(d) large surface area

ignore references to type of metal or external conditions

1black / dark (colour)

1[13]

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Q11.(a) (i) decreases (to zero)

1resultant force acts in opposite direction to motion

accept air resistance and weight for resultant forceaccept resultant force acts downwardsdo not accept air resistance increases

1(ii) velocity includes direction

orvelocity is a vector (quantity)

1(b) (i) 3.6

allow 1 mark for correct substitution i.e.½ × 0.05 × 122 provided no subsequent step

2(ii) 3.6 or their (i)

1(iii) 7.2

ortheir (ii) ÷ 0.5 correctly calculated

allow 1 mark for correct substitution i.e.3.6 or their (ii) = 0.05 × 10 × h

2(iv) B

1(c) range increases up to 45°

1range decreases from 45°

the range is a maximum at 45° gains both marksfor any two angles that add upto 90° the range is the same gains both marksthe range increases then decreases gains 1 mark

1[11]

Q12.(a) (i) 5.88 (watts)

an answer of 5.9 scores 2 marksallow 1 mark for correct substitution ie

0.42 = allow 1 mark for an answer of 0.0588 or 0.059

2(ii) 8.12

allow 14 – their (a)(i) correctly calculated1

(b) (i) input power / energy would be (much) less (reducing cost of running)

accept the converseelectricity is insufficient

1(also) produce less waste energy / power

accept ‘heat’ for waste energy1

(as the waste energy / power) increases temperature of the cabinet

1

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so cooler on for less time1

(ii) line graphneed to get both parts correctaccept scattergram or scatter graph

both variables are continuousallow the data is continuous

1(c) number of bulbs used-halogen=24 (LED=1)

1total cost of LED = £30 + £67.20 = £97.20

accept a comparison of buying costs of halogen £36 and LED £30

1total cost of halogen= 24 x £1.50 + 24 x £16.00 = £420orbuying cost of halogen is £36 and operating cost is £384

accept a comparison of operating costs of halogen £384 and LED £67.20allow for 3 marks the difference in total cost is £322.80 if the number 24 has not been credited

1statement based on correct calculations that overall LED is cheaper

must be both buying and operating costsan alternative way of answering is in terms of cost per hour:

buying cost per hour for LED = 0.0625p/£0.000625

buying cost per hour for halogen = = 0.075p/£0.00075a calculation of both buying costs scores 1 mark

operating cost per hour for LED = = 0.14p/£0.0014

operating cost per hour for halogen= = 0.8p/£0.008a calculation of both operating costs scores 1 mark

all calculations show a correct unitall units correct scores 1 mark

statement based on correct calculations of both buying and operating costs, that overall LED is cheaper

correct statement scores 1 mark1

[12]Q13.

(a) water heated by radiation (from the Sun)accept IR / energy for radiation

1water used to heat buildings / provide hot water

allow for 1 mark heat from the Sun heats water if no other marks givenreferences to photovoltaic cells / electricity scores 0 marks

1(b) 2 (minutes)

1.4 × 103 = gains 1 mark

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calculation of time of 120 (seconds) scores 2 marks3

(c) (i) 150 (kWh)1

(ii) £60(.00) or 6000 (p)an answer of £6000 gains 1 markallow 1 mark for 150 × 0.4(0) 150 × 40allow ecf from (c)(i)

2(iii) 25 (years)

an answer of 6000 / 240or6000 / their (c)(ii) × 4gains 2 marksan answer of 6000 / 60or6000 / their (c)(ii) gains 1 mark, ignore any other multiplier of (c)(ii)

3(iv) any one from:

• will get £240 per yearaccept value consistent with calculated value in (c)(iii)

• amount of light is constant throughout the year• price per unit stays the same• condition of cells does not deteriorate

1(d) any one from:

• angle of tilt of cells• cloud cover• season / shade by trees• amount of dirt

1[13]

Q14.(a) conduction

1(b) (i) there is a bigger temperature difference between the water

and the surrounding airaccept the water is hottest / hotter

1so the transfer of energy (from hot water) is faster

accept heat for energyignore temperature falls the fastest

1(ii) 120

allow 1 mark for converting kJ to J correctly, ie 4 032 000

orcorrectly calculating temperature fall as 8°C orallow 2 marks for correct substitution, ie 4 032 000 = m × 4200 × 8answers of 0.12, 19.2 or 16.6 gain 2 marksanswers of 0.019 or 0.017 gain 1 mark

3

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(iii) water stays hot for longer1

so heater is on for less timeaccept so less energy needed to heat water

1so cost of the jacket is soon recovered from) lower energy costs / bills

accept short payback time1

[9]Q15.

(a) (i) produces carbon dioxide / nitrogen oxidesaccept greenhouse gasesignore pollutant gases

1that (may) contribute to global warming

accept causes global warmingdamages ozone layer negates this markaccept alternative answers in terms of: sulfur dioxide / nitrogen oxides causing acid rain

1(ii) carbon capture / storage

answer must relate to part (a)(i)collecting carbon dioxide is insufficient

orplant more treesorremove sulfur (before burning fuel)

1(b) (i) (power station can be used) to meet surges in demand

accept starts generating in a short timecan be switched on quickly is insufficient

1(ii) can store energy for later use

accept renewable (energy resource)accept does not produce CO2 / SO2 / pollutant gases

1(c) (i) turbines do not generate at a constant rate

accept wind (speed) fluctuatesaccept wind is (an) unreliable (energy source)

1(ii) any one from:

• energy efficient lighting (developed / used)use less lighting is insufficient

• increased energy cost (so people more likely to turn off)accept electricity for energy

• more people becoming environmentally aware1

[7]Q16.

(a) any one from:• energy / source is constant• energy / source does not rely on uncontrollable factors

accept a specific example, eg the weather• can generate all of the time

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will not run out is insufficient1

(b) (dismantle and) remove radioactive waste / materials / fuelaccept nuclear for radioactiveknock down / shut down is insufficient

1(c) any two from:

• reduce use of fossil fuelled power stationsaccept specific fossil fuel accept use less fossil fuel

• use more nuclear poweraccept build new nuclear power stations

• use (more) renewable energy sourcesaccept a named renewable energy source do not accept natural for renewable

• make power stations more efficient• (use) carbon capture (technology)

do not accept use less non-renewable (energy) sources

2(d) (by increasing the voltage) the current is reduced

1this reduces the energy / power loss (from the cable)

accept reduces amount of waste energy accept heat for energy do not accept stops energy loss

1and this increases the efficiency (of transmission)

1[7]

Q17.(a) (i) replaced faster than it is used

accept replaced as quick as it is usedaccept it will never run out do not accept can be used again

1(ii) any two from:

two sources required for the mark• wind• waves• tides• fall of water

do not accept water / oceans accept hydroelectric

• biofuelaccept a named biofuel eg wood

• geothermal1

(b) (i) any two from:• increases from 20° to 30°• reaches maximum value at 30°• then decreases from 30°• same pattern for each month

accept peaks at 30° for both marksaccept goes up then down for 1 mark ignore it’s always the lowest at 50°

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2(ii) 648

an answer of 129.6 gains 2 marksallow 1 mark for using 720 value only from table allow 2 marks for answers 639, 612, 576, 618(.75) allow 1 mark for answers 127.8, 122.4, 115.2, 123.75

3(c) (i) (sometimes) electricity demand may be greater than supply (of

electricity from the system)accept cloudy weather, night time affects supply

orcan sell (excess) electricity (to the National Grid)

1(ii) decreases the current

accept increases the voltage1

reducing energy loss (along cables)accept less heat / thermal energy lost / produced

1[10]

Q18.

(a) (i) 1.6 (W)

allow 1 mark for correct substitution ie

2

(ii) 32 (%) / 0.32ortheir (a)(i) ÷ 5 correctly calculated

ignore any units1

(b) (i) any two from:• comparison over same period of time of relative numbers of

bulbs required eg over 50 000 hours 5 CFL’s required to 1 LEDaccept an LED lasts 5 times longer

• link number of bulbs to cost eg 5 CFL’s cheaper than 1 LEDan answer in terms of over a period of 50 000 hours CFLs cost £15.50 (to buy), LED costs £29.85 (to buy) so CFLs are cheaper scores both marksan answer in terms of the cost per hour (of lifetime) being cheaper for CFL scores 1 mark if then correctly calculated scores both marks

• over the same period of time LEDs cost less to operate (than CFLs)

2(ii) any one from:

• price of LED bulbs will dropdo not accept they become cheaper

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• less electricity needs to be generatedaccept we will use less electricity

• less CO2 produced• fewer chips needed (for each LED bulb)• fewer bulbs required (for same brightness / light)• less energy wasted

do not accept electricity for energy1

[6]Q19.

(a) answers must be in terms of nuclear fuelsconcentrated source of energy

idea of a small mass of fuel able to generate a lot of electricity

1that is able to generate continuously

accept it is reliableor can control / increase / decrease electricity generationidea of available all of the time / not dependent on the weatherignore reference to pollutant gases

1the energy from (nuclear) fission

1is used to heat water to steam to turn turbine linked to a generator

1(b) carbon dioxide is not released (into the atmosphere)

1but is (caught and) stored (in huge natural containers)

1[6]

Q20.(a) 9

allow 2 marks for power = 1400 (kW)if a subsequent calculation is shown award 1 mark onlyorallow 1 mark for correct substitution and transformation

power = allow 1 mark for using a clearly incorrect value for power to read a corresponding correct value from the graph

3(b) (i) system of cables and transformers

both required for the markignore reference to pylonsinclusion of power stations / consumers negates the markwire(s) is insufficient

1(ii) (uses step-up transformer to) increase pd / voltage

accept (transfers energy / electricity at) high voltage

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or(uses step-up transformer to) reduce current

accept (transfers energy / electricity at) low currentignore correct references to step-down transformers

1(c) build a power station that uses a non-renewable fuel or biofuel

accept a named fueleg coal or wood

orbuy (lots of) petrol / diesel generators

1stockpile supplies of the fuel

accept fuel does not rely on the weatherorfuel provides a reliable source of energy

accept as an alternative answer idea of linking with the National Grid (1)and taking power from that when demand exceeds supply (1)orwhen other methods failorwhen it is neededanswers in terms of using other forms of renewables is insufficient

1[7]

Q21.(a) 13 500 (J)

allow 1 mark for correct substitution, ie 90 x 10 x 15 provided no subsequent step shown

2(b) 17

or

correctly calculated and answer given to 2 or 3 significant figures

accept 17.3allow 2 marks for an answer with 4 or more significant figures, ie 17.32orallow 2 marks for correct substitution, ie 13 500/ their (a) = ½ x 90 x v2

orallow 1 mark for a statement or figures showing KE = GPE

3(c) work is done

1(against) friction (between the miner and slide)

accept ‘air resistance’ or ‘drag’ for friction1

(due to the) slide not (being perfectly) smoothaccept miners clothing is rough

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orcausing (kinetic) energy to be transferred as heat/internal energy of surroundings

accept lost/transformed for transferredaccept air for internal energy of surroundings

1[8]

Q22.(a) (i) 7.6

allow 1 mark for correct substitution and / or transformation

ie 95 × 8.0

2(ii) 25 (hours)

allow 1 mark for obtaining number of kWh = 200an answer of 26(.3) gains both marks

2(b) any two from

• transferred to the surroundings / air / atmosphere• becomes spread out• shared between (many) molecules• (wasted as) heat / sound

2[6]

Q23.(a) (i) kinetic

accept KEdo not accept movement

1(ii) 0.75

allow 1 mark for correct substitution ie or75 %

an answer 0.75 % or 0.75 with a unit gains 1 mark onlyan answer 75 with or without a unit gains 1 mark only

2(b) any one from:

• large areas of land are floodeduses large areas of land / takes up large areas of land is insufficient

• people's homes may be destroyed• habitat (of animals and plants) lost / damaged

construct is neutralvery noisy is neutral

1(c) (i) system of cables and transformers

both required for the markaccept power lines / wires for cablesignore reference to pylons

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inclusions of power stations / consumers negates answer

1(ii) less energy loss / wasted (in the cables)

accept heat for energydo not accept no energy lossdo not accept electricity for energy

1as the cables are shorter

1[7]

Q24.(a) 1 080 000

allow 1 mark for correct substitutionie ½ × 15 000 × 12 × 12

2(b) any one from:

• KE (of wind) more than doubles• mass of air (hitting blades) more than doubles• area swept out by blades more than doubles

do not accept blades are larger / have a bigger area

• area swept out by blades increases × 41

[3]Q25.

(a) (i) 4allow 1 mark for correct transformation and substitution

ie substitution only scores if no subsequent steps are shown

2(ii) diagram showing two output arrows with one arrow wider

than the other with the narrower arrow labelledelectrical / electricity / useful

1(b) any one from:

• to check reliability / validity / accuracy• to avoid bias

1(c) any two from:

• produce no / less (air) pollutionaccept named pollutantaccept produces no waste (gases)

• energy is freeaccept it is a free resourcedo not accept it is free

• (energy) is renewable• conserves fossil fuel stocks• can be used in remote areas• do not need to connect to the National Grid

2[6]

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Q26.(a) (i) (dismantle and) remove radioactive waste / materials / fuels

accept nuclear for radioactivedo not accept knock down / shut down

1(ii) increases it

do not accept it has a negative effect1

(b) (i) if efficiency is not mentioned it must be impliedanswers in terms of energygenerated only gains no credit

K most efficientorM least efficient

accept K and / or L are more efficient than M1

(efficiency) of K and L increases, (efficiency) of M (almost) constant /slightly reduced

all 3 power stations must be mentioned to get this mark

1(ii) any two from:

• do not know how many (nuclear) power stations there will be• power stations may continue to increase in efficiency• do not know what type of power station new ones will be

accept new methods may be found to generate electricity / energyaccept other ways of generating energy may be expanded

• do not know future energy / electricity demandsaccept we may become more energy efficient

• may be new uses for uranium2

[6]Q27.

(a) (i) 0.75 allow 1 mark for correct transformation and substitutionie 0.15 = 5

2(ii) 2

accept 1.5 ÷ their (a)(i) correctly calculated1

(b) any one from:• seasonal changes

accept specific changes in conditionseg shorter hours of daylight in winter

• cloud coveraccept idea of changemust be stated or unambiguously impliedeg demand for water will not (always) match supply of solar energydo not accept figures are average on its owndo not accept solar panels are in the shade

1[4]

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Q28.(a) (i) tidal / tides

do not accept water / waves1

(ii) any three from:• shorter journey time

accept easier to go from town to townaccept less petrol / fuel used

• less pollution from trafficaccept CO2 / carbon emissions reduced

• energy source is free• energy source / tides are predictable• produces less / no pollutant gases (than fuel burning power

stations)accept no CO2 / greenhouse gases producedaccept air pollution for pollutant gases

• conserves supplies of fossil fuels• uses renewable energy (to generate electricity)• provides employment• no visual / noise pollution

less harm to the environment is insufficientthe electricity is cheaper is insufficientdo not accept produces no radioactive wastethe pollution mark scores twice only if it is clear one reference is to traffic and the other is to electricity generation

3(b) (i) (sometimes) electricity demand may be greater

than supply (of electricity from the system)accept in case turbines / generators fail

orcan sell (excess) electricity (to the National Grid)

1(ii) decreases the current

accept increases the voltage1

reducing energy loss (along cables)accept less heat / thermal energy lost / produced

1[7]

Q29.(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 fisiondo not accept any answer that looks like fusion

1(ii) water heated to produce (high pressure) steam

1

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steam turns turbine which drives generator1

(iii) any two from:• produces no pollutant gases

accept named gas or greenhouse gasesaccept no atmospheric pollutionaccept harmful for pollutantaccept does not contribute to global warmingdo not accept no pollution on its owndo 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 fuelaccept fossil fuels are running outdo not accept fossil fuels are non-renewable unless qualified

• will need to buy less fuel from other countriesaccept no new fossil fuel power stations neededdo not accept it is cheapdo 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 stationsaccept sulfur dioxide / nitrogen oxides for CO2

1 (increased) CO2 increases / contributes to / causes global warming /

greenhouse effectmention of ozone layer negates this markdo not accept CO2 warms atmosphere

1[9]

Q30.(a) (i) replaced faster than it is used

accept replaced as quick as it is usedaccept will never run outdo not accept can be used again

1(ii) any two from:

two sources required for the mark• wind• waves(*)• tides(*)

(*)do not accept water / oceansaccept OTEC

• fall of wateraccept hydroelectric

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• biomass• geothermal

accept a named biomass / biofuel eg wood1

(b) (i) any two from:• increases from 20° to 30°• reaches maximum value at 30°• then decreases from 30°• same pattern for each month

accept peaks at 30° for both marksaccept goes up then down for 1 markignore it’s always the lowest at 50°

2(ii) 864

an answer of 108 gains 2 marksallow 1 mark for using 720 value only from tableallow 2 marks for answers 852, 816, 768, 825allow 1 mark for answers 106.5, 102, 96, 103 (.125)

3(c) the solar cells will not meet demand at all times of the year / day

accept to maintain a constant supply of electricity / energy

or to make up the shortfall in energy required at certain times of the year or to be able to sell surplus electricity (to the National Grid)

accept to provide energy at nightdo not accept because it’s cloudy on it’s own

1[8]

Q31.(a) (i) £190

nb mention idea of cost per J in £ will come to an approx figure full credit givenallow 1 mark for showing that the energy loss through the roof is ¼ of the total energy loss ie 150 / 600

2(ii) £142.50

allow ecf 50 % of their (a)(i) × 1.5 ie their (a)(i) × 0.75

1(b) transferred to surroundings / atmosphere or becomes spread out

1[4]

Q32.(a) only accept answers in terms of the argument of the nuclear power

scientist any three from:• produces a lot of energy for a small mass of fuel or is a concentrated

energy sourceaccept amount for mass

• it is reliable or it can generate all of the time• produces no pollutant gases

accept named gas or greenhouse gases do not accept no pollution

• produces only a small volume of (solid) wasteaccept amount for volume

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• advances in technology will make fuel reserves last much longeraccept an argument in terms of supply and demand

3(b) any one from:

• may leak into the ground / environment• geological changes

accept earthquakes etc• may get into the food chain

do not accept answers in terms of property prices or ‘damages the environment’

• over time if location not correctly recorded it may be excavated1

(c) any three from:• overall add no carbon dioxide to the environment

accept do not add to global warmingaccept they are carbon neutral

• power companies can sell electricity at a higher priceaccept power companies make more profit

• opportunity to grow new type cropaccept specific examples e.g. growing plants in swampsaccept extends the life of fossil fuel reserve

• more jobs• more land cultivated or different types of land utilised

3[7]

Q33.(a) (i) national grid

1(ii) increases voltage / potential difference

accept decrease currentaccept step-up / boosts the voltagedo not accept increases energy / power / currentignore reference to voltage going through

1(iii) any two from:

• reduce currentignore increased voltage / pd

• reduces energy loss / power loss (from cables)accept reduces heat lossdo not accept stops energy loss

• increases efficiency (of distribution)2

(b) any one from:• produces pollutant gases

accept produces carbon dioxide / sulfur dioxide / nitrogen oxidesaccept global warming / greenhouse effect / carbon emissions / air pollution / acid rainignore ozone layerdo not accept carbon monoxide

• produces solid waste / ash / smokeaccept global dimmingignore produces pollution

1(c) (i) any two from:

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any two valid points gains the marks• using renewable energy

accept don’t use up non-renewable / fossil fuelsaccept named fuels

• non-renewable fuels can be used for other processes• no pollutant gases produced

accept the opposite of (b)ignore no pollution

• land can still be used for farmingignore economic issues

2(ii) any two from:

• cause noise pollution• cause visual pollution

accept spoils the landscapeaccept sunlight flicker

• may interfere with TV / radio / mobile phone signals• need to put in new infrastructure

accept new roads needed• not reliable owtte• dangerous to birds• lots of concrete needed for the bases or producing cement is environmentally damaging

accept reduces house pricesignore any references to cost / jobs / number requiredignore takes up a lot of landaccept reference to obstruction of shipping etc. if clear reference tooffshore wind farm

2[9]

Q34.(a) four calculations correctly shown

200 × 10 – 1800 = £200100 × 10 – 2400 = –£140050 × 10 – 600 = –£10020 × 10 – 75 = 125accept four final answers only or obvious rejection of solar water heater and underfloor heating, with other two calculations completed any 1 complete calculation correctlyshown or showing each saving × 10 of all four calculations = 1 mark answers in terms of savings as a percentage of installation cost may score savings mark only

2hot water boiler

correct answers only1

(b) less electricity / energy to be generated / needed from power stationsaccept less demand

1reduction in (fossil) fuels being burnt

accept correctly named fuel

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accept answer in terms of:fewer light bulbs required because they last longer (1 mark)less energy used / fuels burnt in production / transport etc. (1 mark)ignore reference to CO2 or global warmingignore reference to conservation of energy

1[5]

Q35.(a) hydrogen converted to helium

1(nuclear) fusion

1 ((small) loss in mass) which is converted to large amount of energy

1 (b) (i) any two from

it is running out/ takes millions of years/finitenot non renewableallow acid rain do not allow waste

pollution or problem with CO2 productionallow a specific example

more responsible to use fossil fuels for(important) chemical functions

2(ii) any three from need lots of land for generators or many generators needed generators may not be conveniently located

uncertainty of supplyaccept the wind may not always blow

social resistance or visual pollutionnoise pollutionhigh initial costs

(possible) interference with (local) radio and TV signals3

[8]

Q36.(a) internal or thermal or heat or kinetic or movement electrical

both answers required for one mark1

(b) (i) Sun or solardo not accept sunshine

1(ii) any one of the follow:

• wind turbines produce no (gaseous) pollutants• wind turbines use renewable energy• wind turbines produce no (solid) waste• reduced running costs

do not allow safety1

a supporting statement or comparison or explanation1

[4]Q37.

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To gain marks the candidate must1. Select one option Advantages )

Max 42. State 8 valid advantages/disadvantages/relevant Disadvantages)

Min 1comparisons with either of the alternatives Comparisons ) If no A or D or C then Max 4 No option then Max 4Look for As, Ds for chosen scheme.Then for Cs compared with A/D for chosen scheme.

Below are listed some of the relevant mark scoring points. Advantages Disadvantages Wind Land available to North Initial cost

No pollution Many windmills/much land Close/low transmission costs Calm day problem No fuel costs Few long term jobs Renewable energy resource

Coal Waste land to North Pollution Prevailing wind to East Initial costs Good road/rail transport Fuel costs Close/low transmission costs Non-renewable energy Save coal industry Resource Overall labour intensive

Hydroelectric No pollution Possible drought Mountains/lake/river nearby Distant/transmission costs No fuel costs Few jobs created Renewable energy source Possible expensive underground transmission cable Construction of dam affects environment

[8]Q38.

(a) 90% of 2.10112.16.1011

2(b) (i) Can be located anywhere

Continuous outputSustain coal industry

any 2 for 1 mark each(ii) Low running cost

No atmospheric pollutionGives calm coastal waters

any 2 for 1 mark each(iii) High installation costs – built in sea

Coast environmental damage – wildlife disturbanceTime dependence – need dropping tide

any 2 for 1 mark each(1 for a valid disadvantage, 1 for reason)

6[8]

Q39.coal has chemical energy

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when burnt heat/energy produced longestused to boil water/make steam sequenceused to turn turbine(s)which now have keturbine(s) turn generator(s)(where (ke) transferred electrical energy)(or electrical energy produced )

any 5 for 1 mark each[5]

Q40.the higher the voltage the smaller the currentsmall current gives small energy lossin the form of heat(or efficiency greater, or energy/heat losses low – gets 1)

for 1 mark each[3]

Q41.(a) (i) much ash produced

acid rainglobal warming/greenhouse effect

any 2 for 1 mark each2

(ii) landscaping/road building*removal of exhaust gases*use alternative source not producing CO2* (*sequential (i))

for 1 mark each2

(b) (i) E = 5 × 108 × 3600 × 24 J/day× 4 (for 4 generators) (sequential on P × t) = 1.73 × 1014 (J/day)

for 1 mark each3

(ii) 2.66 × 1010 × 18 829 = 4.86 × 1014 for 1 mark each

2(iii) Eff = output/input

Eff = 1.73/4.86Eff = 0.36 or worked to a percentage

for 1 mark each3

(c) (i) boiler – heat to surroundingsturbine – not all steam energy used/heat/sound lost to surroundingsgenerator – heat in wires/coils/heat to surroundingstransformer – heat in wires/coils/heat tosurroundings

any 1 for 1 mark1

(ii) energy spread out/dilutedas surroundings become warmer/energy lost as heatdifficult to use for further useful energy/transfers

any 2 for 1 mark each2

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[15]Q42.

(a) product of mass and velocity1

(b) (i) 4kg or 4000g1

(ii) M = 8kgm/s or Nsfor 3 marks

else M = 8for 2 marks

else M – mv or 4 × 2for 1 mark

3(iii) 8 kgm/s (watch e.c.f.)

1(iv) v = 400

for 3 marks else v = 8/0.02

for 2 marks else M – mv, v – M/m or 8 = 0.02v

for 1 mark3

(v) ke = 8for 3 marks

else ke = 1/2 (4 × 22)for 2 marks

else ke = 1/2 (mv2)for 1 mark

3(vi) transferred to heat and sound

or does work against wood/pushing wood aside/deforming bullet1

[13]Q43.

(a) must give one advantage and one disadvantage of each to get 4 marksand 2 further scoring pointsAdvantages and disadvantages relevant to:(1) health risk(5) cost(6) environmental factors(7) transport/ storagee.g. common coal / nuclear – high cost of building both

anti-nuclear examplesnuclear fuel transported on roads/rail in regionpossible effects on public health in surrounding areahigh cost of de-commissioninglong life very active waste materials producedhow waste materials stored safely for a long time

anti-coal examplesunsightlypollutionsupplies of fuel limitedacid rainnon-renewable

pro-nuclear examplesfuel cheap

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no foreseeable fuel shortage pro-coal examples

safereliablelarge coal reservesdisposal of solid waste is easier

to max 66

(b) choice 0 marks any three valid reasons each with explanation, which may or may not

be comparisons with other fuel But at least two of which must be relevant to this site

3[9]

Q44.do not give any credit for renewable or non-renewable or installation or decommissioning costs

fossil fuel advantage1

a reliable source of energy fossil fuel disadvantage pollution by carbon dioxide /

accept causes acid rainaccept highest costs / more expensive than nuclear / more expensive than renewable

1 nuclear advantage do not produce gases that increase the

greenhouse effect or cause acid rainaccept nuclear is cheaper than fossil

1 nuclear disadvantage accidents / waste can release very dangerous radioactive material radiation

accept it produces waste that stays dangerously radioactive for thousands of years or radioactive waste has to be stored safely for thousands of years

1 renewable advantage there are no fuel costs

almost pollution free (apart from noise and visual)accept cheaper than fossil

1 renewable disadvantage not a reliable source of energy except for hydroelectric

accept (most) require large areas of landaccept visual / noise pollution

1[6]

Q45.(a) (oil / natural gas / coal)

no marks are given for choosing the correct non-renewable energy source

burning releases carbon dioxide (1) greenhouse effect (1) OR

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allow 2 effects for 2 marks burning (releases sulphur dioxide (1) acid rain (1) OR (nuclear power)

no marks given for choosing the correct non-renewable energy source

accidents can release very dangerous radioactive material (1) produces waste that stays dangerously radioactive for thousands of years

orradioactive waste has to be stored safely for thousands of years (1)

accept the cost of installation and decommissioning is high

2(b) any four from: (wind power)

no marks are given for choosing the correct non-renewable energy source

• considered unsightly / visual pollution (1) very large areas of land (1)• noisy for people living nearby / noise pollution (1)

(tidal power)no marks are given for choosing the correct non-renewable energy source

• barrages / visual pollution (1)• destroys the habitat of many living organisms (1)

(hydroelectricity)no marks are given for choosing the correct non-renewable energy source

• damming / visual pollution (1)• very large areas of land (1) flooding (1)

4[6]

Q46.(a) any two from

reliableaccept it is not always windy

can be used as storage for surplus electricitygenerates more electricity

accept would need hundreds of wind turbines to generate this electricitytakes less space is neutral

no noise pollutiondo not accept can be started up quickly

2(b) advantage : does not produce greenhouse gases / carbon dioxide / water

or acid rain / sulphur dioxide1

disadvantage :danger from radioactive materials if accidents or waste radioactive materials

accept slower start-up time1

(c) any one situation with a suitable explanation satellite

weigh less or work for many years or remote

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remote places on Earth pump water or operate phones or road signs / lights orweather stations or too expensive / impractical

calculators / watches small amount of electricity needed2

[6]Q47.

(a) any evidence of: momentum = mass × velocity (words, symbols or numbers) appropriate re-arrangement mass as 0.05kg

each gains 1 mark but 800

gains 4 marks4

(b) (i) any reference to friction with air/air resistancegains 1 mark

but idea that friction with air/air resistance is high (at high speed)gains 2 marks

2(ii) any evidence of: k.e. v2 or k.e. = ½ mv2

final k.e.initial k.e.either initial or final k.e. correctly calculated (i.e. 16000; 10240)

each gains 1 mark but (0.8)2

gains 3 marks but 64%(credit 0.64)

gains 4 marks (also credit e.c.f)4

[10]Q48.

ideas that• direct solar radiation will provide enough energy to heat the (specially

designed) buildings during the period Oct-Mar / summer• solar cells will produce plenty of electricity in Oct-Mar / summer (when wind

generators produce little)• a couple of wind generators will produce all electricity needed (for all but

heating) Apr-Oct / winter• number required makes wind generators unsuitable for heating / buildings• no solar energy in June and July / little in winter• solar / wind have little effect on environment• or cause no air pollution• solar and wind complement each other• or together provide energy all year• fuel / gas / diesel can provide energy all the time / at any time• fuel / gas / diesel needed for transport • fuel / gas / diesel needed for heating in winter• diesel has to be imported• diesel likely to freeze• gas wouldn’t have to be imported• drilling for gas difficult / harms environment• but atmospheric pollution a global rather than local matter so any produced

in Antarctic doesn’t matter much (deduct 1 mark (to minm. zero) for incorrect claims about destroying ozone layer)

• gas produces less carbon dioxide (for the same energy released) than diesel*

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• gas produces less sulphur dioxide (for the same energy released than diesel*

(* these ideas met by candidates in Q.16 so must be allowed, though not required)

any ten for 1 mark each[10]

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