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1.3 National and global energy resources - Standard demand – Questions
Q1.
A small community of people live in an area in the mountains.
The houses are not connected to the National Grid.
The people plan to buy an electricity generating system that uses either the wind or the flowing water in a nearby river.
Figure 1 shows where these people live.
Figure 1
© Brian Lawrence/Getty Images
(a) It would not be economical to connect the houses to the National Grid.
Give one reason why.
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(1)
(b) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Information about the two electricity generation systems is given in Figure 2.
Figure 2
The wind turbine costs £50 000 to buy and install.
The hydroelectric generator costs £20 000 to buy and install.
The average power output from the wind turbine is 10 kW.
The hydroelectric generator will produce a constant power output of 8 kW.
Compare the advantages and disadvantages of the two methods of generating electricity.
Use your knowledge of energy sources as well as information from Figure 2.
(6)
(Total 7 marks)
Q2.
The image shows a solar thermal power station.
© Kim Steele/Photodisc/Thinkstock
Energy from the Sun is directed at the solar receiver by many mirrors.
@
(a) (i) Suggest one reason why a solar thermal power station is built in a hot desert.
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(1)
(ii) Complete the following sentence to describe how the mirrors direct energy from the Sun towards the solar receiver.
Energy from the Sun is __________________________ by the mirrors
towards the solar receiver.
(1)
(iii) Heated water is used to generate electricity in the solar thermal power station.Choose the correct answer from the box to complete each sentence.
boiler
motor
transformer
turbine
At the solar receiver, water is heated in a ____________________
which turns the water into steam. The steam turns a
__________________which is connected to a water into steam. The
steam turns a __________________ which is connected to a generator.
The generator produces electricity. A ____________________ is used
to change the voltage for transmission along power lines.
(3)
(b) A solar storage power station is a new type of solar power station.It is able to store energy from the Sun to generate electricity at night.
The solar storage power station can supply a town with a maximum electrical power of 140 000 kW for 15 hours.
Calculate the maximum energy, in kWh, stored by the solar storage power station.
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Energy = ______________________________ kWh
(2)
(c) A different method of generating electricity uses wind turbines.A student researching a wind farm wrote the following.
Top Hill Wind Farm has 25 wind turbines.Last week, one of the wind turbines generated electricity for only 42 hours out of a possible 168 hours.My conclusion is that all wind turbines operate for only 25% of the time.
(i) Give two reasons why the student is not correct in reaching his conclusion.
1. ____________________________________________________________
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2. ____________________________________________________________
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(2)
(ii) Give one reason why wind turbines do not generate electricity all the time.
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(1)
(iii) Give one advantage of using wind turbines to generate electricity compared with using fossil fuel power stations.
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(1)
(Total 11 marks)
Q3.
Electricity can be generated using various energy sources.
(a) Give one advantage and one disadvantage of using nuclear power stations rather than gas-fired power stations to generate electricity.
Advantage __________________________________________________________
___________________________________________________________________
Disadvantage _______________________________________________________
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(2)
(b) (i) A single wind turbine has a maximum power output of 2 000 000 W.
The wind turbine operated continuously at maximum power for 6 hours.
Calculate the energy output in kilowatt-hours of the wind turbine.
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Energy output = ____________________ kWh
(2)
(ii) Why, on average, do wind turbines operate at maximum power output for only 30% of the time?
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(1)
(c) An on-shore wind farm is made up of many individual wind turbines.
They are connected to the National Grid using underground power cables.
Give one advantage of using underground power cables rather than overhead power cables.
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(1)
(Total 6 marks)
Q4.
(a) Iceland is a country that generates nearly all of its electricity from renewable sources.
In 2013, about 80% of Iceland’s electricity was generated using hydroelectric power stations (HEP).
Describe how electricity is generated in a hydroelectric power station. Include the useful energy transfers taking place.
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(4)
(b) The UK produces most of its electricity from fossil fuels.
Many people in the UK leave their televisions in ‘stand by’ mode when not in use, instead of switching them off.
It is better for the environment if people switch off their televisions, instead of leaving them in ‘stand by’ mode.
Explain why.
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(3)
(c) A scientist wrote in a newspaper:
‘Appliances that do not automatically switch off when they are not being used should be banned.’
Suggest why scientists alone cannot make the decision to ban these appliances.
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(1)
(Total 8 marks)
Q5.
(a) The graph shows how the demand for electricity in the UK changes during one 24-hour period.
Time of day
The table gives the start-up times for two types of power station.
Type of power station
Start-up time
Gas
A few minutes
Nuclear
Several days
How would these two types of power station be used to meet the demand for electricity during this 24-hour period?
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(3)
(b) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
A farmer plans to generate all the electricity needed on her farm, using either a biogas generator or a small wind turbine.
The biogas generator would burn methane gas. The methane gas would come from rotting the animal waste produced on the farm. When burnt, methane produces carbon dioxide.
The biogas generator would cost £18 000 to buy and install. The wind turbine would cost £25 000 to buy and install.
The average power output from the wind turbine would be the same as the continuous output from the biogas generator.
Evaluate the advantages and disadvantages of the two methods of generating electricity.
Conclude, with a reason, which system would be better for the farmer to buy and install.
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(6)
(Total 9 marks)
Q6.
The diagram shows the National Grid system.
(a) The National Grid includes step-up transformers.
Explain why.
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(2)
(b) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Over the next 10 years, more than 300 kilometres of new high voltage transmission cables are to be added to the National Grid. Most of the new cables will be suspended from pylons and run overhead while the rest will be buried underground.
Outline the advantages and disadvantages of both overhead transmission cables and underground transmission cables.
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(6)
(c) When an electric current flows through a transmission cable, a magnetic field is produced.
The graph shows how the strength of the magnetic field varies with distance from both overhead and underground transmission cables that carry the same current.
What conclusions may be drawn from this graph?
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(2)
(d) Some people think that, because of the magnetic fields, living close to transmission cables is dangerous to health. Laboratory studies on mice and rats exposed to magnetic fields for two or more years found that the magnetic fields had no effect on the animals’ health.
Draw a ring around the correct answer in the box to complete the sentence.
economic
Using animals in scientific research raises
environmental
issues.
ethical
(1)
(Total 11 marks)
Q7.
(a) Geothermal energy and the energy of falling water are two resources used to generate electricity.
(i) What is geothermal energy?
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(1)
(ii) Hydroelectric systems generate electricity using the energy of falling water.
A pumped storage hydroelectric system can also be used as a way of storing energy for future use.
Explain how.
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(2)
(b) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Read the following extract from a newspaper.
Discuss the advantages and disadvantages of the plan to build thousands of offshore wind turbines around Britain and the suggested electricity power link between Britain and Iceland.
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(6)
(Total 9 marks)
Q8.
A farmer has installed a biogas electricity generator on his farm. This device generates electricity by burning the methane gas produced from rotting animal waste. Methane is a greenhouse gas. When methane burns, carbon dioxide and water are produced.
The animal waste rots in an anaerobic digester. The digester and the generator are kept inside a farm building and cannot be seen from the outside.
(a) The animal waste used in the anaerobic digester is a renewable energy source.
What is meant by an energy source being renewable?
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(1)
(b) Suggest one reason why farmers have been encouraged to install their own biogas generators.
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(1)
(c) The farmer’s monthly electricity bill using the mains electricity supply was £300.The biogas generator cost the farmer £18 000 to buy and install.
Assuming the biogas generator provides all of the farmer’s electricity, what is the pay-back time for the generator?
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Pay-back time = ______________________________
(1)
(d) It would have been cheaper for the farmer to have bought and installed a small wind turbine.
Give two advantages of using the biogas generator rather than a wind turbine, to generate the electricity used on the farm.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
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(2)
(Total 5 marks)
Q9.
(a) An electricity company claims to generate all of its electricity from environmentally friendly energy sources.
The energy sources used by the company are shown in the pie chart.
Do you think that the claim made by the company is correct?
Draw a ring around your answer.
Yes
No
Maybe
Explain the reasons for your answer.
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(2)
(b) The government is committed to increasing the amount of electricity generated from renewable sources. A newspaper reported that:
Why is the statement made in the newspaper incorrect?
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(1)
(Total 3 marks)
Q10.
(a) By 2023, nearly all of the existing nuclear power stations in the UK will be closed down.
(i) Before a nuclear power station can be demolished, the remaining nuclear fuel, radioactive waste materials and reactor must be carefully removed.
What is this process called?
Put a tick () in the box next to your answer.
decommissioning
decontaminating
dismantling
(1)
(ii) The workers are exposed to radiation as they remove the reactor. One of the biggest risks is from the isotope cobalt-60, which has a half-life of 5.3 years.
Explain the advantage of waiting 11 years after a nuclear power station has closed down before starting to remove the reactor.
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(2)
(b) It is almost certain that new nuclear power stations will be built in the UK.
The table shows the results of surveys asking people in the UK whether they were in favour of, or against, the building of new nuclear power stations.
2001
2005
2007
Percentage (%) in favour
20
41
65
Percentage (%) against
60
28
20
Percentage (%) not sure
20
31
15
(i) From these surveys, how did public opinion on the building of new nuclear power stations change between 2001 and 2007?
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(1)
(ii) Suggest a reason why some people may think that the results from these surveys are unreliable.
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(1)
(iii) Give one reason in favour of building new nuclear power stations.
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(1)
(c) The government of one Middle Eastern country has decided to build its first nuclear power station. The oil that would have been used to generate electricity can then be sold to other countries.
On what is this decision based?
Put a tick () in the box next to your answer.
economic issues
ethical issues
social issues
(1)
(Total 7 marks)
Q11.
The bar chart shows how the UK’s electricity demands in 2007 were met.
(a) What proportion of electricity was generated using renewable energy sources?
Show clearly how you work out your answer.
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(2)
(b) By 2020, most of the UK’s nuclear reactors and one-third of coal-fired power stations are due to close, yet the demand for electricity is expected to increase.
Four students, A, B, C and D, were asked how a demand of 380 billion kilowatt-hours could be met. They made the suggestions given in the table.
Student
Fossil fuels
Nuclear
Renewable
Bought from other countries
A
200
100
40
40
B
80
240
40
20
C
160
80
100
40
D
280
0
100
0
(i) Which student has made the suggestion most likely to result in the lowest carbon dioxide emissions?
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Give a reason for your answer.
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(2)
(ii) Suggest one realistic way in which a householder could help to reduce the annual electricity demand.
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(1)
(c) To increase the amount of electricity generated using renewable energy resources would probably involve erecting many new wind turbines.
The graph shows the power curve of a wind turbine.
(i) Describe, in detail, how the power output of the turbine varies with the wind speed.
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(3)
(ii) Give one disadvantage of using wind turbines to generate a high proportion of the electricity required in the UK.
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(1)
(Total 9 marks)
Q12.
(a) Electricity is distributed from power stations to consumers along the National Grid.
(i) Transformers are part of the National Grid. Transformers are efficient devices. What is meant by a device being efficient?
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(1)
(ii) When electricity flows through a cable, some energy is transformed into heat.
Explain how the National Grid system reduces the amount of energy lost as heat.
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(2)
(b) Read this information taken from a recent newspaper article.
• Researchers have found that children living close to overhead power cables are more likely to develop leukaemia.
• The researchers studied two groups of children. One group had developed leukaemia, the other group was healthy.
• Although the researchers found a link, they are unable to explain why it happened. They say that the results may have happened by chance.
• Other factors that have not been investigated, such as the environment, the geographical area or the children’s genes, could be important.
• A cancer research charity said that childhood leukaemia was most likely to be caused by factors that parents were unable to control.
(i) Why did the researchers study a group of healthy children?
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(1)
(ii) The information does not say how many children were studied.
Why should this data have been included in the article?
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(1)
(iii) The researchers could not be certain that the overhead power cables were responsible for the increased chance of children developing leukaemia.
Explain why.
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(2)
(iv) The results of the research carried out by scientists may worry some people.
What do you think scientists should do?
Put a tick () in the box next to your choice.
Scientists should publish their research findings straight away.
Scientists should not publish their research findings until they have found out as many facts as possible.
Give a reason for your choice.
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(1)
(Total 8 marks)
Q13.
(a) (i) A student wrote "Coal traps energy from the Sun". Explain what the student means.
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(2)
(ii) How is energy released from coal?
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(1)
(b) The diagram shows the waste products from a coal-fired power station.
(i) In what form does the power station waste energy?
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(1)
(ii) Carbon dioxide released into the atmosphere will lead to a rise in the Earth’s temperature. Why?
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(1)
(Total 5 marks)
Q14.
In a traditional power station 30% of the energy input is usefully transferred to electricity, the rest is wasted as heat. The diagram shows the energy transfers in a combined heat and power (CHP) station.
Explain why replacing traditional power stations by CHP stations may be beneficial to the environment.
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(Total 2 marks)
Q15.
(a) Coal, gas, oil and wood are all examples of fuels.
(i) What are fuels?
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(1)
(ii) Write the names of these fuels in the table below to show which are renewable and which are non-renewable.
(2)
(b) The list below shows energy resources which are not fuels.
geothermal nuclear solar tides wind
Write the names of the energy resources in the table below to show which are renewable and which are non-renewable.
(2)
(c) Why is it better to use more renewable energy resources rather thannon-renewable resources?
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(2)
(Total 7 marks)
Q16.
The outline diagram below shows part of the National Grid. At X the transformer increases the voltage to a very high value. At Y the voltage is reduced to 240 V for use by consumers.
(i) At X a transformer increases the voltage. What happens to the current as the voltage is increased?
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(1)
(ii) Why is electrical energy transmitted at very high voltages?
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(1)
(iii) The transformer at Y reduces the voltage before it is supplied to houses. Why is this done?
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(1)
(Total 3 marks)
Q17.
State and explain the advantages and disadvantages of using nuclear power stations to produce electricity.
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(Total 4 marks)
Q18.
The drawing shows a hydro-electric dam. Water from the top of the dam flows through pipes to the power station at the bottom of the dam.
(a) Complete the following boxes to show the useful energy transfer which occurs as the water flows through the pipes to the power station.
(2)
(b) The electricity generated by the power station is transmitted over long distances. Before this happens its voltage is increased by using a step-up transformer.
State and explain one advantage and one disadvantage of transmitting electricity at high voltage.
Advantage _________________________________________________________
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Disadvantage ______________________________________________________
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(4)
(Total 6 marks)
Q19.
Electricity may be produced from a number of different energy resources.
(i) Complete the table below.
The first one has been done for you.
Device
Energy resource
Useful energy transfer from resource
Coal-fired power station
Coal
Chemical electrical
Hydroelectric power station
Stored water
__________ electrical
Solar cell in calculator
Sun
__________ electrical
Wind turbine
Wind
__________ electrical
Gas-fired power station
Gas
__________ electrical
(4)
(ii) Give one of the five energy resources opposite, which is not classified as renewable.
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(1)
(iii) State another non-renewable energy resource.
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(1)
(Total 6 marks)
Q20.
The table shows the main sources of energy used in Britain in 1990.
coal
35%
oil
35%
gas
24%
nuclear
5%
moving water(hydro)
1%
(a) Finish the pie-chart, using the figures in the table.
(4)
(b) Complete the following sentences.
To release energy from coal, gas and oil they must be burned.
Coal, gas and oil are all _______________________________
(1)
(c) Which one of the energy sources in the table is renewable? ___________________
Write down the name of one other renewable energy source. __________________
(2)
(d) How does the amount of energy obtained from nuclear sources in 1990 compare with the amount obtained from moving water?
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(2)
(Total 9 marks)
Q21.
The table shows the main sources of the energy used in Britain in 1990.
coal
35%
oil
35%
gas
24%
nuclear
5%
moving water(hydro)
1%
(a) Finish the pie-chart, using the figures in the table.
(3)
(b) How does the amount of energy obtained from nuclear sources in 1990 compare with the amount obtained from moving water?
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(1)
(c) Moving water (hydro) is a renewable energy source.
Write down the name of one other renewable energy source.
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(1)
(d) Explain why electricity is not included in the table of energy sources.
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(1)
(Total 6 marks)
Q22.
On a very windy hilltop there are two wind generators side by side.
The bar charts show the lengths of the turbine blades and the electrical outputs of the two wind generators.
Complete the following table.
LENGTH OF TURBINEBLADE (m)
ELECTRICAL OUTPUT(MW)
Large wind generator
60
Small wind generator
(Total 3 marks)
Q23.
(a) The pie-chart shows how energy is used in a home.
Complete the table using the information on the pie-chart.
(2)
(b) We get some of the energy we need in our homes from electricity.
The graphs show how the amounts of coal and gas used to generate electricity changed between 1960 and 1990.
Describe these changes.
Coal _______________________________________________________________
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Gas _______________________________________________________________
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(4)
(c) Read the information below.
• More carbon dioxide in the air may change the weather. Farmers may then not be able to produce the food we need.
• Burning coal produces sulphur dioxide. Burning gas does not do this.
• It is cheaper to generate electricity from gas than from coal.
• Sulphur dioxide causes acid rain which can kill fish and damagebuildings.
• Two power stations generate the same amount of electricity. Theone which burns gas produces less carbon dioxide than the otherwhich burns coal.
Many people say that the change from coal to gas is better for the environment.
Why do you think they say this?
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(3)
(Total 9 marks)
Q24.
A student goes camping and uses a panel of solar cells to charge his mobile phone, as shown in Figure 1.
Figure 1
(a) Give one disadvantage of using a panel of solar cells to generate electricity to charge a mobile phone.
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(1)
(b) A new camping stove has been invented that uses burning wood to cook food and to generate electricity.
Figure 2 shows the new camping stove and a fossil fuel gas camping stove.
Figure 2
New camping stove
Fossil fuel gas camping stove
The new camping stove has a USB connection to charge portable devices such as mobile phones.
Suggest two other advantages of using the new camping stove instead of a fossil fuel gas camping stove.
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(2)
(Total 3 marks)
Q25.
A student goes camping and uses a panel of solar cells to charge his mobile phone, as shown in Figure 1.
Figure 1
(a) Give one disadvantage of using a panel of solar cells to generate electricity to charge a mobile phone.
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(1)
(b) A new camping stove has been invented that uses burning wood to cook food and to generate electricity.
Figure 2 shows the new camping stove and a fossil fuel gas camping stove.
Figure 2
New camping stove
Fossil fuel gas camping stove
The new camping stove has a USB connection to charge portable devices such as mobile phones.
Suggest two other advantages of using the new camping stove instead of a fossil fuel gas camping stove.
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(2)
(c) Another version of the new camping stove, called a home-stove, has been designed for use in Africa and is shown in Figure 3.
Figure 3
Home-stove
It can be used to cook food and generate electricity. The total power output of the stove is 5 kW. The maximum electrical power output is 20 W.
In African villages, there are three methods that can be used to heat food, a traditional three-stone fire, a basic stove and the home-stove as shown in Figure 4.
Figure 4
Three-stone fire
Basic stove
Home-stove
A scientist investigated the wood burnt and the carbon dioxide and smoke emitted when each method was used to boil the same volume of water.
Figure 5 shows the results of the investigation. The results for the basic stove and home-stove are relative to the three-stone fire.
Figure 5
Three-stone fire Basic stove Home-stove
(i) Give two advantages of using the home-stove compared to the other two methods.
You must use information in Figure 5.
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(2)
(ii) The home-stove is a reliable method of generating electricity.
Suggest two reasons why home-stoves are unlikely to be connected to a national grid in Africa.
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(2)
(Total 7 marks)
Q26.
A student is investigating how the voltage output of a solar cell depends on the area of the solar cell exposed to light.
He shines a desk light at a solar cell. He varies the area of the solar cell exposed to the light and records the voltage output.
The graph shows the student’s results.
Area exposed to light in cm2
(a) One of the results on the graph is anomalous.
(i) Draw a ring around the anomalous result on the graph.
(1)
(ii) Suggest what the student could do about the anomalous result.
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(1)
(b) Give two conclusions that can be made from these results.
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(2)
(c) Most houses use electricity from the National Grid.
Some houses have panels made from many solar cells joined together. These panels produce electricity for the house.
(i) Houses with panels of solar cells remain connected to the National Grid.
Give two reasons why.
______________________________________________________________
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(2)
(ii) Producing electricity for a house using solar cells is better for the environment than using electricity from coal-fired power stations.
Give two reasons why.
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(2)
(Total 8 marks)
Q27.
(a) The pie chart shows how the electricity generated in the UK is produced using different energy resources.
(i) Which energy resource is used to generate approximately one third of the UK’s electricity?
______________________________________________________________
(1)
(ii) Name two energy resources that could be part of the ‘Other’ energy resources used to generate electricity in the UK.
1. ____________________________________________________________
2. ____________________________________________________________
(2)
(b) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Fossil fuel power stations burn coal, oil and gas. Burning these fuels pollutes the atmosphere with greenhouse gases. The government is considering investing in new nuclear power stations, rather than relying on fossil fuel power stations.
The government is also considering more investment in alternative energy resources. Wind power may be used because the UK is a very windy country. In one year, there is enough wind in the UK to supply all of our electricity needs.
Do you think the government should invest in wind power or nuclear power?
Draw a ring around the energy resource that you think the government should invest in.
Nuclear / Wind
Discuss the advantages of the energy resource you have chosen and the disadvantages of the energy resource you did not choose.
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(6)
(Total 9 marks)
Q28.
A community of people living on an island are considering buying wind turbines to supply their electricity. The community have looked at two types of wind turbine.
Vertical Axis Wind Turbine
Horizontal Axis Wind Turbine
Not to scale
The community looked at information about the two different types of wind turbine.
• Vertical axis wind turbines start to rotate at wind speeds of 1.5 m/s.
• Horizontal axis wind turbines start to rotate at wind speeds of 3.6 m/s.
• Vertical axis wind turbines are powered by wind coming from any direction.
• Horizontal axis wind turbines turn to point into the wind.
• The power output at 12 m/s is 1 MW.
• The power output at 12 m/s is 1 MW.
• The wind turbines continue to generate electricity until the wind speed reaches 40 m/s.
• At very high wind speeds, above 20 m/s, the wind turbines stop working automatically to avoid damage.
(a) The community decide that vertical axis wind turbines would be better.
Use the information given to suggest why.
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(3)
(b) Graph 1 shows how the power output varies with wind speed for a vertical axis wind turbine.
Graph 1
Wind speed in m/s
Describe how the power output of this wind turbine varies with wind speed for the range of wind speeds shown.
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(2)
(c) Some local people do not want the wind turbines. These people say the wind turbines are too noisy.
Graph 2 shows how the sound level detected changes with distance from a wind turbine.
Sound level is measured in decibels, dB.
Graph 2
Distance from wind turbine in metres
The sound level of a normal conversation is 50 dB.
(i) How far from the wind turbine would a person need to stand to detect a sound level of 50 dB?
Distance = _________________________ metres
(1)
(ii) The graph shows that 1000 m away you can still hear the noise the wind turbines produce.
A sound level of 30 dB is the same as a person whispering in another person’s ear.The nearest house to the wind turbine is 1000 m away.
Some people do not want the wind turbines because of the noise the wind turbines produce.
Are these people justified in not wanting wind turbines?
Give reasons for your answer.
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(2)
(d) On the mainland, wind turbines are connected to the National Grid.
Electricity is transmitted through the power lines of the National Grid at very high voltages and low currents.
State why.
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(1)
(Total 9 marks)
Q29.
A nuclear power station generates electricity using nuclear fuel.
The diagram below shows a nuclear power station.
(a) The transformer changes the voltage of the electricity generated by the power station.
(i) What type of transformer is shown in the diagram?
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(1)
(ii) Changing the voltage increases the efficiency of the power transmission.
Explain how.
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(2)
(b) A country generates 80% of its electricity using fossil fuel power stations.
The country’s government is considering replacing all of its fossil fuel power stations with nuclear power stations.
Suggest two factors that the country's government will have to consider in making a decision.
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(2)
(Total 5 marks)
Q30.
China’s economy is growing quickly. To make sure electricity supplies match demand, China is building more coal-fired power stations. These power stations will probably use carbon capture and storage technology.
A lot of people believe that energy resources like falling water should be used instead of energy resources like coal. Hydroelectric power stations generate electricity using the energy of falling water.
A large-scale hydroelectric power station can generate the same amount of electricity as a coal-fired power station.
Photograph supplied by AbleStock.com/Thinkstock
Apart from the emission of carbon dioxide by coal-fired power stations, give two advantages and two disadvantages of generating electricity using hydroelectric power stations instead of using coal-fired power stations.
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(Total 4 marks)
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