P1 07 Generation of Energy
336 minutes
336 marks
Q1.
(a) The bar chart shows the start-up time for different types of fuel-burning power
stations.
Which type of power station would be the quickest to start producing electricity?
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(1)
(b)
A fuel-burning power station is more reliable than a wind generator at producing
electricity. Explain why.
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(2)
(c)
Fuel-burning power stations may produce air pollution. Why does a wind generator not
produce any air pollution?
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(1)
(Total 4 marks)
Q2.
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?
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(1)
(ii)
What does a step-up transformer do?
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(1)
(iii)
Explain why step-up transformers are used in the electricity distribution system.
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(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.
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(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?
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(2)
(ii)
What reasons may be given by the people who think that wind farms are not a good
idea?
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(2)
(Total 9 marks)
Much of the world’s electricity is generated in power stations that burn fossil fuels.
Q3.
(a)
The bar chart shows the start-up times for the three types of fossil fuel power station.
Which of these power stations would take the longest to start generating electricity?
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(1)
(b)
Which two of the following statements are good reasons for using fossil fuels to generate
electricity?
Put a tick ( ) in the box next to each of your choices.
Supplies of fossil fuels are limited.
Fossil fuels can be used to generate electricity at any time.
Fossil fuels are non-renewable.
A few large power stations can generate the electricity for a million homes.
Burning fossil fuels produces carbon dioxide.
(2)
(c)
Electricity can be generated using energy from the wind.
(i)
Why does a wind-powered generator not produce carbon dioxide?
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(1)
(ii)
Which form of energy is transferred from the wind to generate electricity?
Draw a ring around your answer.
heat
kinetic
light
sound
(1)
(iii)
Many people say that wind-powered generators are a good idea because:
“when the wind blows they generate electricity”
“they produce no pollution”
“they generate electricity cheaply”
But not everyone wants more wind-powered generators to be built.
What reasons may be given by the people who think that wind-powered generators
are not a good idea?
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(2)
(Total 7 marks)
What reasons may be given by the people who think that wind-powered generators
are not a good idea?
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(2)
(Total 7 marks)
Q4.
The diagram shows how electricity gets from power stations to consumers.
(a)
Complete the following sentences by drawing a ring around the correct line in each box.
(i)
The network of cables and transformers linking power stations to consumers is
grid
called the national
line
network
(1)
(ii)
decreases voltage
A step-up transformer
increases current
increases voltage
(1)
(iii)
230 V
Electricity is supplied to consumers’ homes at
25 000 V
400 000 V
(1)
(iv)
increase
Making the current in the cables smaller will
make no difference to
the
reduce
energy lost in the cables.
(1)
(b)
Transformers always waste some energy.
(i)
What effect does the waste energy from a transformer have on the air around the
transformer?
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(1)
(ii)
Which one of the following describes the efficiency of a transformer?
Draw a ring around your answer.
always 100 %
less than 100 %
more than 100%
(1)
(Total 6 marks)
Q5.
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.
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(3)
(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.
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(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.
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(3)
(Total 7 marks)
Q6.
(a)
(i)
Solar energy is a renewable energy source that can be used to generate electricity.
What is meant by an energy source being renewable?
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(1)
(ii)
Name two further renewable energy sources used to generate electricity.
1 .......................................................................................................................
2 .......................................................................................................................
(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.
Angle of tilt
Month
(i)
20°
30°
40°
50°
February
460
500
480
440
April
600
620
610
600
June
710
720
680
640
August
640
660
640
580
October
480
520
500
460
December
400
440
420
410
Use the data in the table to describe how the average energy input to the solar cells
depends on the angle of tilt.
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(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
Use the equation in the box to calculate the average maximum electrical energy
available from the bank of solar cells each second in June.
efficiency =
Show clearly how you work out your answer.
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Maximum energy = .................................................. joules/second
(3)
(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?
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(1)
(Total 8 marks)
Q7.
(a)
Different energy sources are used to generate electricity.
Which two of the energy sources in the box are likely to be used up first?
Draw a ring around each of your answers.
gas
oil
Sun
tides
waves
wind
(2)
(b)
The diagram shows a geothermal power station. Hot rocks in the Earth’s crust heat water
to produce steam. The steam is used to drive turbines that turn electrical generators.
How is the way in which a geothermal power station generates electricity the same as the
way in which a coal burning power station generates electricity?
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(1)
(c)
The graph shows how the temperature of the rocks in the Earth’s crust depends on how
far the rocks are below the Earth’s surface.
Estimate the temperature of the rocks 5 kilometres below the Earth’s surface.
Show clearly how you have used the graph to get your answer.
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Temperature = ................................................. °C
(2)
(d)
Scientists have estimated that one quarter of the world’s electricity could be generated
using geothermal energy.
Give one reason that scientists might use to persuade a government to spend large
amounts of money building geothermal power stations.
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(1)
(Total 6 marks)
Q8.
(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.
•
be
A cancer research charity said that childhood leukaemia was most likely to
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)
Q9.
(a)
Water waves are a renewable energy source.
The government wants more electricity to be generated from renewable energy sources.
Some people do not think this is a good idea.
What reasons could a government scientist give to show people that using more
renewable energy sources is a good idea?
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(2)
(b)
The diagram shows a wave-powered generator. The generator transforms kinetic energy
from the waves to electrical energy.
AQA GCSE SCIENCE CORE FOUNDATION STUDENT’S BOOK by Graham Hill,
Nigel Heslop, Christine Woodward,Steve Witney and Toby Houghton. Published by
Hodder and Stoughton 2006 © Reproduced by permission of John Murray (Publishers) Ltd
The following sentences describe how the wave generator works. The sentences are in
the wrong order.
R
S
T
U
V
Waves push air up and down a chamber inside the building.
The turbine turns the generator.
The generator transforms kinetic energy to electrical energy.
The air rushes through a turbine making it spin.
Strong waves move towards the wave-powered generator.
Arrange these sentences in the correct order. Start with letter V.
V
(3)
(Total 5 marks)
Q10.
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.
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(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?
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(1)
(ii)
Explain how the heat released from a nuclear fuel is used to generate electricity in
power stations.
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(2)
(iii)
Some people have suggested that more nuclear power stations should be built in
the UK.
Give two reasons to support this suggestion.
1 ........................................................................................................................
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2 ........................................................................................................................
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(2)
(iv)
Nuclear power stations create dangerous waste.
Why is the waste from a nuclear power station dangerous?
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(1)
(c)
A headline from a newspaper article is shown below.
Explain the possible link between climate change and coal-burning power stations.
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(2)
(Total 9 marks)
Q11.
Electrical appliances that are left on standby still use energy.
The bar chart compares the average amount of ‘standby energy’ wasted each year in every
home in five countries.
(i)
In which country are the homes that waste, on average, the smallest amount of
‘standby energy’?
Draw a ring around your answer.
Australia
France
Japan
UK
USA
(1)
(ii)
Suggest a reason why an average value is used for the ‘standby energy’ wasted in
the homes.
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(1)
(b)
(i)
Australia has one of the lowest electricity prices in the world.
How does this low price seem to affect the amount of ‘standby energy’ wasted?
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(1)
(ii)
In Australia, most electricity is generated in coal-burning power stations.
The Australian government wants less electricity to be wasted.
Wasting less electricity would be good for the Australian environment.
Explain why.
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(2)
(c)
Energy is not usually measured in kilowatt-hours.
Which one of the following units is usually used to measure energy?
Draw a ring around your answer.
hertz
joule
watt
(1)
(d)
(i)
Electricity in Japan costs the equivalent of 17 pence per kilowatt-hour.
Use the information in the bar chart and the equation in the box to calculate
howmuch the ‘standby energy’ used in an average Japanese home costs each year.
total cost = number of kilowatt-hours × cost per kilowatt-hour
Show clearly how you work out your answer.
Give your answer in pence.
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Cost = ........................................ pence
(3)
(ii)
In Japan, the largest proportion of electricity is generated using nuclear fuels.
Which one of the following statements gives a good reason for using nuclear fuels to
generate electricity?
Put a tick ( ) in the box next to your answer.
A nuclear power station is very expensive to build.
A small amount of nuclear fuel generates a large amount of electricity.
It is easy to store nuclear waste safely.
(1)
(Total 10 marks)
Q12.
Wind and tides are renewable energy sources that are used to generate electricity.
(a)
Complete each sentence by putting a tick ( ) in the box next to the correct answer.
(i)
The wind is:
a predictable energy source.
a constant energy source.
an unreliable energy source.
(1)
(ii)
The tides are:
a predictable energy source.
a constant energy source.
an unreliable energy source.
(1)
(b)
If wood is to be used as a renewable energy source, what must be done each time a tree
is chopped down?
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(1)
(c)
In the UK, electricity is generated using renewable and non-renewable energy sources.
The graph shows the percentage of electricity generated using renewable energy sources
between 1990 and 2005.
Complete the following sentence by drawing a ring around the correct line in the box.
In 2015, the percentage of electricity generated using renewable energy sources is most
likely to be
greater than
4%
.
equal to 4%
less than 4%
(1)
(Total 4 marks)
Q13.
Electricity is generated in power stations. It is then sent to all parts of the country through a
network of cables.
(a)
Complete the following sentence by using one of the words in the box.
Grid
Power
Supply
The network is called the National ............................................................................ .
(1)
(b)
In the diagram, A, B, C and D are transformers.
(i)
Which transformer, A, B, C or D, is a step-up transformer?
Transformer ..............................
(1)
(ii)
Which transformer, A, B, C or D, will supply homes, offices and shops?
Transformer ..............................
(1)
(c)
Complete the following sentence by drawing a ring around the correct line in the box.
In a step-down transformer, the potential difference (p.d.) across the
less than
primary coil is
the same as
the p.d. across the secondary coil.
more than
(1)
(Total 4 marks)
Q14.
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)
Q15.
The bar chart shows the different energy sources used to generate the UK’s electricity in
2007.
(a)
(i)
The wind is a renewable energy source.
Name one more renewable energy source used to generate electricity.
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(1)
(ii)
Complete the following sentence by drawing a ring around the correct line in the
box.
decrease
Using less fossil fuels to generate electricity will
not change
increase
the
amount of carbon dioxide emitted into the atmosphere.
(1)
(b)
The graph shows how the demand for electricity in the UK varied over one day in the
winter.
(i)
Describe how the demand for electricity varied between 4.00 am and 10.00 am.
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(2)
(ii)
Which type of power station has the fastest start-up time?
Draw a ring around your answer.
coal
natural gas
nuclear
oil
(1)
(Total 5 marks)
Q16.
The picture shows a solar-powered aircraft. The aircraft has no pilot.
Photo by NASA.
(a)
Use words from the box to complete the following sentence.
electrical
heat
light
sound
Solar cells are designed to transform .............................................................. energy into
.............................................................. energy.
(2)
(b)
On a summer day, 175 000 joules of energy are supplied to the aircraft’s solar cells every
second. The useful energy transferred by the solar cells is 35 000 joules every second.
(i)
Use the equation in the box to calculate the efficiency of the solar cells.
Show clearly how you work out your answer.
...........................................................................................................................
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Efficiency = ..............................................................
(2)
(ii)
What happens to the energy that is not usefully transferred by the solar cells?
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(1)
(c)
The aircraft propellers are driven by electric motors. As well as the solar cells, there are
fuel cells that provide additional power to the electric motors.
(i)
Suggest one advantage of the aircraft having fuel cells as well as the solar cells.
...........................................................................................................................
(1)
(ii)
Give one environmental advantage of using electric motors to drive the aircraft
propellers rather than motors that burn a fuel.
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(1)
(iii)
Eventually, the designers want to produce an unmanned aircraft that can fly at twice
the height of a passenger jet for up to six months.
Suggest one possible use for an aircraft such as this.
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(1)
(Total 8 marks)
Q17.
The diagram shows the National Grid system.
Transformers X and Y are an essential part of the National Grid system.
Explain why.
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(Total 4 marks)
Q18.
The pie charts show the relative proportions of electricity generated in Japan from different
energy sources in 1975 and 2005.
(a)
Describe and suggest a reason for two differences in the energy sources used in
2005compared with 1975.
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(2)
(b)
Mining for coal often releases large amounts of methane gas. Methane is both
explosiveand a greenhouse gas. At the Sihe coal mine in China the methane is diverted to
a gas burning power station where it is used to generate electricity.
(i)
A newspaper reported a scientist as saying:
If the concentration of greenhouse gases in the atmosphere
doubles, the average temperature of the Earth will increase by up
to 5 °C over the next 100 years.
What has been stated in the newspaper?
Draw a ring a round your answer.
a fact
a guess
a prediction
Give a reason for your answer.
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(2)
(ii)
Explain an environmental advantage of taking the methane gas from coal mines
andusing it to generate electricity.
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(2)
(c)
The average person in Britain uses 1930 kWh of electricity each year. Many people in the
world’s poorest countries do not have access to electricity.
Giving examples, explain why electricity is essential for both improving public health and
for modern communications.
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(3)
(Total 9 marks)
Q19.
(a)
The block diagram shows the important parts of a coal burning power station.
Use words from the box to complete the block diagram
boiler
condenser
furnace
generator
(2)
(b)
The diagram shows the energy transformations in a coal burning power station.
Calculate the efficiency of the power station.
Write down the equation you use, and then show clearly how you work out your answer.
........................................................................................................................
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Efficiency = ............................................
(2)
(c)
Draw a ring around the correct answer to complete the following sentence.
If fewer coal burning power stations are used to generate electricity the amount of
decrease.
carbon dioxide emitted into the atmosphere will
not change.
increase.
(1)
(d)
Some types of power station generate electricity by burning a biofuel.
Give one example of a biofuel.
........................................................................................................................
(1)
(e)
Nuclear power stations generate electricity without burning a fuel.
Name the process by which a nuclear fuel provides the energy needed to generate
electricity.
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(1)
(Total 7 marks)
Q20.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.
Reason 1 ..............................................................................................
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Reason 2 ..............................................................................................
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Reason 3 ..............................................................................................
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(3)
(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.
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(2)
(Total 7 marks)
Q21.
Four students are talking about the different energy sources used to generate electricity in
the areas where they live.
(a)
Draw one line from where each student lives (List A) to the energy source in their area
(List B).
Draw only four lines.
List A
Where each student lives
List B
Energy
source
Wind
Where I live is the sunniest part
of the country.
Waves
Where I live, the land is very flat
and it always seems to be windy.
Solar
Where I live, it is not safe to swim.
The sea is always too rough.
Tides
Where I live, you can see steam
coming out of the ground.
Geothermal
(4)
(b)
All of the energy sources given in part (a) can be used to generate electricity.
What else do all these energy sources have in common?
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(1)
(c)
In a hydroelectric power station, the energy from falling water is used to generate
electricity.
Which one of the following gives a disadvantage of a hydroelectric power station?
Put a tick (
) in the box next to your answer.
has a fast start-up time
large areas of land are flooded
polluting gases are produced
(1)
(Total 6 marks)
Q22.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 15 years.
(ii)
Suggest reasons why it is not possible to predict accurately how much uranium will
be needed in 2025.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(Total 6 marks)
Q23.
(a)
Most electricity in the UK is generated in power stations that burn fossil fuels.
The bar chart shows how much carbon dioxide is produced for each kilowatt-hour of
electricity generated using a fossil fuel.
(i)
Which fossil fuel produces the smallest amount of carbon dioxide for each kilowathour of electricity generated?
............................................................
(1)
(ii)
Which one of the following statements gives the reason why the data has been
shown as a bar chart and not as a line graph?
Put a tick (
) in the box next to your answer.
Both variables are categoric.
Both variables are continuous.
One variable is categoric, the other is continuous.
(1)
(iii)
Why does a nuclear power station not produce any carbon dioxide?
...............................................................................................................
...............................................................................................................
(1)
(b)
Some types of power station generate electricity by burning straw.
(i)
Use words from the box to complete the following sentences.
boiler
gas
generator steam
turbine
water
Straw is burned in a ............................................ Water is heated to make
...................................... which is used to drive a ....................................
This turns a ....................................... to produce electricity.
(4)
(ii)
Straw is a type of renewable energy source known as a biofuel.
Name one other type of renewable energy source used to produce electricity.
...............................................................................................................
(1)
(iii)
A power station generates 36 000 000 watts (36 MW) of electrical power by burning
straw. The average power used in each home in the UK over one year is 2000
watts.
Calculate the number of homes that the power station could supply electricity to.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
Number of homes = ..................................................
(2)
(Total 10 marks)
Q24.
(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)
Use the following equation to calculate the average energy input each second to the
device.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
Average energy input each second = .................................... J/s
(2)
(ii)
Draw a labelled Sankey diagram for the solar cells.
The diagram does not need to be drawn to scale.
(1)
(iii)
Energy from the Sun is stored by a rechargeable battery inside the device.
Suggest one factor that would affect the time it takes to fully charge the battery.
Give a reason for your answer.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(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 8 marks)
Q25.
(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.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(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.
(i)
2001
2005
2007
Percentage (%) in favour
20
41
65
Percentage (%) against
60
28
20
Percentage (%) not sure
20
31
15
From these surveys, how did public opinion on the building of new nuclear power
stations change between 2001 and 2007?
...............................................................................................................
...............................................................................................................
(1)
(ii)
Suggest a reason why some people may think that the results from these surveys
are unreliable.
...............................................................................................................
...............................................................................................................
(1)
(iii)
Give one reason in favour of building new nuclear power stations.
...............................................................................................................
...............................................................................................................
(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)
Q26.
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 potential
energy of the falling water
................................
energy
of the Archimedean screw
Electrical energy
generated
(1)
(ii)
Use the equation in the box to calculate the efficiency of the microhydroelectricitygenerator.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
Efficiency = ............................................................
(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)
Q27.
(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.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(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?
........................................................................................................................
........................................................................................................................
(1)
(Total 3 marks)
Q28.
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)
Complete the following sentence by drawing a ring around the correct word in the box.
The gravitational potential energy of the falling water is transformed
chemical
into
the
electrical energy of the Archimedean screw.
kinetic
(1)
(b)
A micro-hydroelectric generator is very efficient. Most of the input energy from the falling
water is transformed into useful electrical energy.
Which one of the following Sankey diagrams, X, Y or Z, shows the energy transformations
produced by this generator?
Write your answer, X, Y, or Z, in the box.
Sankey diagram X
Sankey diagram Y
Sankey diagram Z
Sankey diagram
(1)
(c)
A micro-hydroelectric system generates about 60 kW of electricity, enough for 50 homes.
A conventional large-scale hydroelectric power station may generate more than 5 000 000
kW of electricity.
(i)
Give one advantage of a conventional large-scale hydroelectric power station
compared to a micro-hydroelectric system.
...............................................................................................................
...............................................................................................................
(1)
(ii)
Which one of the following statements gives a disadvantage of a conventional
large-scale hydroelectric power station compared to a micro–hydroelectric system?
Put a tick (
) in the box next to your answer.
Energy is wasted as heat and sound.
Large areas of land are flooded.
A constant flow of water is needed.
(1)
(d)
The electricity generated by the micro-hydroelectric system is transferred directly to local
homes. The electricity generated by a conventional large-scale hydroelectric power station
is transferred to homes anywhere in the country through a system of cables and
transformers.
(i)
What name is given to the system of cables and transformers used to transfer
electricity to homes anywhere in the country?
..............................................................................
(1)
(ii)
Using short cables to transfer electricity to local homes is much more efficient than
using very long cables to transfer electricity to homes anywhere in the country.
Why?
...............................................................................................................
...............................................................................................................
(1)
(e)
Nepal is a mountainous country with over 6000 rivers. In Nepal, 9000 kW of electricity are
generated using micro-hydroelectric generators.
Suggest one reason why in the UK much less electricity is generated using microhydroelectric generators, than in Nepal.
........................................................................................................................
........................................................................................................................
(1)
(Total 7 marks)
Q29.
(a) The pie chart shows the energy sources used by one company to generate
electricity.
(i)
Which two energy sources used by the company do not produce any polluting
gases?
............................................. and .............................................
(1)
(ii)
Calculate the percentage (%) of electricity that is generated using energy sources
that do not produce any polluting gases.
Percentage = .............................................
(1)
(b)
Which graph, A, B or C, is most likely to show the electrical power output from a wind
turbine over one day?
Write your answer, A, B or C, in the box.
Graph A
Graph B
Graph C
Graph
(1)
(c)
The government has said that more electricity must be generated from renewable energy
sources. A newspaper reported that:
Why is the statement in the newspaper incorrect?
........................................................................................................................
........................................................................................................................
(1)
(Total 4 marks)
Q30.
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?
........................................................................................................................
........................................................................................................................
(1)
(b)
Suggest one reason why farmers have been encouraged to install their own biogas
generators.
........................................................................................................................
........................................................................................................................
(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 payback time for the generator?
........................................................................................................................
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 .....................................................................................................................
........................................................................................................................
(2)
(Total 5 marks)
Q31.
(a) Geothermal energy and the energy of falling water are two resources used to
generate electricity.
(i)
What is geothermal energy?
...............................................................................................................
...............................................................................................................
(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.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(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.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(6)
(Total 9 marks)
Q32.
In the UK, most electricity is generated in power stations that burn fossil fuels.
(a)
Which type of fossil fuel power station has the shortest start-up time?
........................................................................................................................
(1)
(b)
The diagram shows how electricity is distributed around the UK.
(i)
Which of the parts labelled in the diagram form the National Grid?
...............................................................................................................
(1)
(ii)
A step-up transformer is used near the power station.
Draw a ring around the correct answer in each box to complete each sentence.
current.
A step-up transformer increases the
power.
voltage.
less dangerous.
Using a step-up transformer makes the distribution of electricity
more efficient.
work faster.
(2)
(c)
Electricity in the UK is also generated without using fossil fuels.
The graph shows how the percentage of electricity generated in the UK without using
fossil fuels changed between 1990 and 2010.
What does the data in the graph suggest will probably happen to the percentage of electricity
generated in the UK without using fossil fuels over the next 10 years?
........................................................................................................................
........................................................................................................................
(1)
(Total 5 marks)
Q33.The world’s biggest offshore wind farm, built off the Kent coast, started generating electricity in
September 2010.
(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 equation in the box and the data in the graph to calculate the average wind speed
during this 4-hour period.
energy transferred
=
power
×
time
Show clearly how you work out your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Average wind speed = ........................................ m/s
(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
doesnot happen in the future.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 7 marks)
Q34.The world’s biggest offshore wind farm, built off the Kent coast, started generating electricity in
September 2010.
(a)
One advantage of using the wind to generate electricity is that it is a renewable energy
source.
(i)
Give one other advantage of using the wind to generate electricity.
...............................................................................................................
...............................................................................................................
(1)
(ii)
Name one other renewable energy source used to generate electricity.
...............................................................................................................
(1)
(b)
The graph shows how wind speed affects the power output from a large wind turbine.
(i)
What is the maximum possible power output from this wind turbine?
........................................................
(1)
(ii)
Read this part of a newspaper article.
Use the graph to explain why the power output from the wind turbines was less than
one sixth of the maximum.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(iii)
Having more nuclear power stations will help to avoid power cuts in the future.
Which two of these reasons explain why?
Put a tick (
) in the boxes next to your answers.
A small amount of nuclear fuel generates a large amount of electricity.
The radioactive waste produced must be stored for many years.
Nuclear power stations do not depend on the weather to generate electricity.
(1)
(Total 6 marks)
Q35.The world’s biggest offshore wind farm, built off the Kent coast, started generating electricity in
September 2010.
(a)
One advantage of using the wind to generate electricity is that it is a renewable energy
source.
(i)
Give one other advantage of using the wind to generate electricity.
...............................................................................................................
...............................................................................................................
(1)
(ii)
Name one other renewable energy source used to generate electricity.
...............................................................................................................
(1)
(b)
The graph shows how wind speed affects the power output from a large wind turbine.
(i)
What is the maximum possible power output from this wind turbine?
........................................................
(1)
(ii)
Read this part of a newspaper article.
Use the graph to explain why the power output from the wind turbines was less than
one sixth of the maximum.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(iii)
Having more nuclear power stations will help to avoid power cuts in the future.
Which two of these reasons explain why?
Put a tick (
) in the boxes next to your answers.
A small amount of nuclear fuel generates a large amount of electricity.
The radioactive waste produced must be stored for many years.
Nuclear power stations do not depend on the weather to generate electricity.
(1)
(Total 6 marks)
M1.
(a)
gas
1
(b)
fuel burning stations produce electricity at any time / all the time
accept fuel available all the time
1
wind generator can only produce when the wind is strong enough
accept it’s not always windy
1
(c)
no fuel is burnt or no fuel is used or uses only energy from wind or
does not emit harmful gases / soot / smoke
do not accept wind is natural / environmentally friendly /
renewable
answer must be in terms of wind, not negative of fuel burning
specific examples of gases CO2, SO2,
acid rain and greenhouse gases can be accepted
ozone negates credit
1
[4]
M2.
(a)
(i)
national grid
1
(ii)
increases voltage / potential difference
accept decrease current
accept step-up / boosts the voltage
do not accept increases energy / power / current
ignore reference to voltage going through
1
(iii)
any two from:
•
reduce current
ignore increased voltage / pd
•
reduces energy loss / power loss (from cables)
accept reduces heat loss
do not accept stops energy loss
•
increases efficiency (of distribution)
2
(b)
any one from:
•
produces pollutant gases
accept produces carbon dioxide / sulfur dioxide / nitrogen oxides
accept global warming / greenhouse effect / carbon emissions / air
pollution / acid rain
ignore ozone layer
do not accept carbon monoxide
•
produces solid waste / ash / smoke
accept global dimming
ignore produces pollution
1
(c)
(i)
any two from:
any two valid points gains the marks
•
using renewable energy
accept don’t use up non-renewable / fossil fuels
accept 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 farming
ignore economic issues
2
(ii)
any two from:
•
cause noise pollution
•
cause visual pollution
accept spoils the landscape
accept 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 prices
ignore any references to cost / jobs / number required
ignore takes up a lot of land
accept reference to obstruction of shipping etc. if clear reference
tooffshore wind farm
2
[9]
M3.
(a)
coal
1
(b)
fossil fuels can be used to generate electricity at any time
if more than 2 boxes ticked, mark incorrect boxes first
1
a few large power stations can generate the electricity for a million homes
1
(c)
(i)
no fuel is burnt
accept a named fuel
accept nothing is burnt
accept does not use (fossil) fuel
1
(ii)
kinetic
1
(iii)
any two from:
accept causes pollution for 1 mark
•
need concrete for bases
•
new roads / infrastructure needed
•
may interfere with TV / radio / mobile
phone signals
•
dangerous to birds
•
do not generate all of the time
accept generates only when the wind blows
do not accept ‘generate when the wind blows’
•
need a lot of generators
do not accept ‘take up a lot of space / land’
•
high initial / capital costs
•
reduces house prices
2
[7]
M4.
(a)
(i)
grid
accept any way of indicating correct answer
1
(ii)
increases voltage
accept any way of indicating correct answer
1
(iii)
230 V
accept any way of indicating correct answer
1
(iv)
reduce
accept any way of indicating correct answer
1
(b)
(i)
increases the temperature
accept make it hotter / heat goes into the air
accept convection currents
accept sensible comment eg sound energy / it buzzes
ignore pollutes the air
1
(ii)
less than 100%
1
[6]
M5.
(a) only accept answers in terms of the argument of the nuclear power scientist
any threefrom:
•
produces a lot of energy for a small mass of fuel or is a concentrated energy source
accept 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) waste
accept amount for volume
•
advances in technology will make fuel reserves last much longer
accept 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 excavated
1
(c)
any three from:
•
overall add no carbon dioxide to the environment
accept do not add to global warming
accept they are carbon neutral
•
power companies can sell electricity at a higher price
accept power companies make more profit
•
opportunity to grow new type crop
accept specific examples e.g. growing plants in swamps
accept extends the life of fossil fuel reserve
•
more jobs
•
more land cultivated or different types of land utilised
3
[7]
M6.
(a)
(i)
replaced faster than it is used
accept replaced as quick as it is used
accept 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(*)
(*)do not accept water / oceans
accept OTEC
•
fall of water
accept hydroelectric
•
biomass
•
geothermal
accept a named biomass / biofuel eg wood
1
(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 marks
accept goes up then down for 1 mark
ignore it’s always the lowest at 50°
2
(ii)
864
an answer of 108 gains 2 marks
allow 1 mark for using 720 value only from table
allow 2 marks for answers 852, 816, 768, 825
allow 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 night
do not accept because it’s cloudy on it’s own
1
[8]
M7.
(a)
gas
1
oil
1
(b)
(both) use steam to drive a turbine
accept (both) use turbines to drive generators
do not accept both have a turbine /generator / use steam
must describe a step in the process
accept heat / thermal energy transformed to kinetic / electrical
energy
1
(c)
140 (°C)
correct answer only
allow 1 mark for method clearly shown on graph
accept a cross or other indication at correct position on the line
accept correct description
accept even if numerical answer is incorrect
2
(d)
any one from:
do not accept answers purely in terms of disadvantages of other
methods except for fossil fuels are running out
•
very large energy source / reserves
•
no polluting / harmful gases produced
accept named gas CO2 SO2 NOx
accept reduces harmful carbon emissions
•
reduces carbon emissions
accept does not contribute to global warming
•
no fuel needed
•
energy is free
•
can generate energy for a long time
accept energy available for a long time
•
renewable (energy source)
•
fossil fuels are running out
accept it saves fossil fuels / non-renewable
accept reduces the amount of fossil fuels being burnt
accept a named fossil fuel
Better for the environment / environmentally friendly insufficient
it is cheaper is insufficient
1
[6]
M8.
(a)
(i)
small proportion of energy / power is wasted
accept little / less energy / power / heat is wasted
do not accept it wastes no energy / power
or transfers most / more / a lot of energy power usefully
1
(ii)
it decreases the current / uses low current
or it increases the voltage / potential difference
accept pd for potential difference
1
or uses high voltage / potential difference
smaller the current the smaller the energy loss
accept power / heat for energy
1
(b)
(i)
as a control
accept to make a comparison
do not accept fair test on its own
1
(ii)
so people know how much data the link was based on
accept idea that larger numbers are better
or
people can judge the significance / reliability of the link
do not accept significance / reliability on its own
ignore reference to accuracy
1
(iii)
other possible factors may be responsible
1
or have not been investigated
named factor eg environment / genetic
1
(iv)
first box ticked plus reason
acceptable reason such as so people know there may be a risk as
soon as possible / so that other scientists can use findings
or second box plus reason
acceptable reason such as no point to worry / confuse / panic
people (until the research has been confirmed)
accept idea that it may lead to wrong advice
do not accept in case they are wrong
1
[8]
M9.
(a)
any two from:
•
(burning) fossil fuels produces greenhouse gases / pollutant gases / acid rain / leads
to global warming
accept a named fossil fuel
accept a named pollutant gas
•
nuclear fuels produce dangerous waste
accept radioactive for dangerous
accept reference to dangers of nuclear fuels
•
fossil fuels are non-renewable
accept running out of fuels
•
renewable energy resources produce no pollutant gases
•
large amounts of energy are available
accept renewable won’t run out
•
running costs are low
accept any reasonable benefit of renewables
accept any reasonable drawback of non-renewables
do not accept better for the environment on its own
2
(b)
RUST
all in correct order
allow 2 marks for 2 correct
allow 1 mark for one correct
3
[5]
M10.
(a)
decrease in oil
PLUS
any one from:
•
increase in (proportion of) coal
•
increase in (proportion of) nuclear
•
increase in (proportion of) gas
must have decrease in (proportion of) oil and increase in
(proportion of) coal / nuclear / gas
1
(b)
(i)
(nuclear) fission
accept fision
do not accept any answer that looks like fusion
1
(ii)
water heated to produce (high pressure) steam
1
steam turns turbine which drives generator
1
(iii)
any two from:
•
produces no pollutant gases
accept named gas or greenhouse gases
accept no atmospheric pollution
accept harmful for pollutant
accept does not contribute to global warming
do not accept no pollution on its own
do not accept better for the environment unless qualified
•
it is reliable or can generate all of the time
•
concentrated energy source or produces a lot of energy from a small mass
•
produces only small volume of (solid) waste
•
fossil fuels will last longer
accept a named fossil fuel
accept fossil fuels are running out
do not accept fossil fuels are non-renewable unless qualified
•
will need to buy less fuel from other countries
accept no new fossil fuel power stations needed
do not accept it is cheap
do not accept import less electricity
2
(iv)
it is / can be radioactive
do not accept answers in terms of kills cells / cancer
or emits radiation (from the nuclei)
accept emits gamma (rays)
1
(c)
coal (burning) power stations / burning coal produces carbon dioxide
they refers to coal-burning power stations
accept sulfur dioxide / nitrogen oxides for CO2
1
(increased) CO2 increases / contributes to / causes global warming /
greenhouse effect
mention of ozone layer negates this mark
do not accept CO2 warms atmosphere
1
[9]
M11.
(a)
(i)
France
1
(ii)
any one from:
•
different homes have different appliances(*)
•
different homes have different numbers of appliances(*)
(*) accept all homes are different
•
standby power not the same for all appliances
•
some people will switch appliances off
accept named appliances
accept people waste different amounts of energy
•
homes have different numbers of residents
•
can’t measure every (individual) home
accept any sensible suggestions
do not accept answers in terms of accurate / precise etc
1
(b)
(i)
increases amount of energy wasted
accept (encourages) people to leave appliances on (standby)
accept increases it
1
(ii)
any two from:
•
less electricity needed / generated
•
fewer power stations needed
•
less coal is burned
do not accept coal is non-renewable / running out
answers in terms of fuel stocks neutral
•
less pollutant gases produced
accept named gases
accept harmful for pollutant
accept greenhouse gases
accept reduce / slow / stop global warming
accept reduces acid rain
2
(c)
joule
1
(d)
(i)
6800
accept £68 for 3 marks an answer of 68 gains 2 marks
allow 2 marks for correct substitution ie 400 × 17
allow 1 mark for obtaining 400
answers of 7480, 4760, 12920, 4080 gain 2 marks
3
(ii)
a small . . . . . . electricity
1
[10]
M12.
(a)
(i)
an unreliable energy source
1
(ii)
a predictable energy source
1
(b)
plant / grow (at least) one new tree
1
(c)
greater than 4 %
1
[4]
M13.
(a)
grid
accept any unambiguous indication
1
(b)
(i)
A (only)
1
(ii)
D (only)
1
(c)
more than
accept any unambiguous indication
1
[4]
M14.
(a)
1/25 or 1:25 or 0.04
accept 4 % or
or 1 in 25 for both marks
allow 1 mark for total of 375
allow 1 mark for a clearly correct method using a clearly incorrect
total
do not accept 1:26
2
(b)
(i)
B
do not credit reason if B is not chosen
1
(only) burning fossil fuels produces carbon
dioxide / carbon (emissions)
or nuclear fuels don’t produce carbon dioxide
insufficient – smallest amount of fossil fuels
accept less carbon dioxide
1
(ii)
accept anything reasonable eg
increased level of insulation
use energy efficient light bulbs
do not leave appliances on standby
switch thermostats down (1°C)
generate own electricity
install solar panels
accept insulate
accept specific examples eg loft
1
(c)
(i)
any three from:
•
no power output until wind speed exceeds 4m/s
•
output rises rapidly after 4m/s
•
output begins to level out / rises less rapidly at /
after 13m/s
•
output peaks at 21 / 22m/s
•
output constant between 21 / 22 and 25 / 26 m/s
•
output falls (rapidly) after 25 / 26m/s
accept for 1 mark goes up then comes down
3
(ii)
any one from:
•
unreliable energy source
•
dilute energy source
•
take up too much land
accept wind does not always blow
accept need thousands / lots of turbines
ignore reference to visual / noise pollution
ignore reference to kill birds
1
[9]
M15.
(a)
(i)
any one from:
•
waves
do not accept water
•
tides
•
falling water
accept hydroelectric
•
biofuel / biomass
•
solar
accept sun / sunlight
do not accept light
accept solar cells / panels
•
geothermal
do not accept heat
1
(ii)
decrease
1
(b)
(i)
increases from 4am (to 8am) remains constant from 8am (to 10am)
accept increases from 30 000
accept stays constant from 40 000
allow 1 mark for goes up then stays the same
for full credit must be some indication of time or power
2
(ii)
natural gas
1
[5]
M16.
(a)
light
1
electrical
correct order only
1
(b)
(i)
0.2 or 1/5
accept 20% for both marks
allow 1 mark for correct substitution answer of 0.2%
or 20 gains 1 mark
ignore units
2
(ii)
wasted
accept transformed to heat / other forms
accept transferred to the air / surroundings sound = neutral
1
(c)
(i)
any one from:
•
can fly at night
accept can fly when it is cloudy
accept as a back-up
•
can stay in the air for longer
•
can fly in the winter
•
can fly faster
increases power is neutral
1
(ii)
any one from:
•
produces no (pollutant) gases
or no greenhouse gases
accept named gas
accept no air pollution
do not accept no pollution
accept less global warming
accept harmful for pollutant
accept produces no carbon
do not accept environmentally friendly
•
produces no / less noise
•
less demand for fuels
accept any other sensible environmental advantage
1
(iii)
accept any sensible suggestion eg, map the Earth’s surface / weather forecasting /
spying / monitoring changes to the Earth’s atmosphere, etc
do not accept ideas in terms of transporting
accept use as a satellite
1
[8]
M17.
transformer X reduces the current through the transmission cables
accept increases p.d. across the cables
1
this reduces the energy loss from the cables
1
which increases the efficiency of the distribution system
1
transformer Y is essential as it reduces the p.d. to a safe
working value for consumers
1
[4]
M18.
(a)
decrease in (proportion of) oil as reserves are decreasing
1
increase in (proportion of) coal / nuclear / gas / as new
reserves / more nuclear power stations built
1
no marks are awarded for simply describing the differences
(b)
(i)
a prediction
1
forecast based on scientific evidence
1
(ii)
less methane goes into the atmosphere
accept air for atmosphere
1
therefore making global warming less rapid
1
(c)
idea that many devices transform electricity into other useful
forms of energy
1
example related to public health eg refrigeration / production of
vaccines / X-ray machines
1
example related to modern communications eg internet / telephones
1
[9]
M19.
(a)
boiler
1
generator
1
(b)
0.3 or 30%
allow 1 mark for substitution of 2 correct values taken from the
Sankey diagram into correct equation
2
(c)
decrease
1
(d)
any named biofuel eg wood, ethanol, straw
1
(e)
(nuclear) fission
1
[7]
M20.
(a)
(i)
tidal / tides
do not accept water / waves
1
(ii)
any three from:
•
shorter journey time
accept easier to go from town to town
accept less petrol / fuel used
•
less pollution from traffic
accept 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 produced
accept 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 insufficient
the electricity is cheaper is insufficient
do not accept produces no radioactive waste
the 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
or
can sell (excess) electricity (to the National Grid)
1
(ii)
decreases the current
accept increases the voltage
1
reducing energy loss (along cables)
accept less heat / thermal energy lost / produced
1
[7]
M21.
(a)
all 4 lines correct
allow 1 mark for each correct line
if more than 1 line goes from a box in List A then all those lines
are incorrect
4
(b)
all renewable
accept a correct description of renewable
eg replaced faster than used or never run out
do not accept can be used again
accept any other common feature
eg do not produce pollution /
polluting (gases)
no fuel is burnt
(energy input) is free
eco-friendly / environmentally friendly / natural resources /
sustainable sources are insufficient
1
(c)
large areas of land are flooded
1
[6]
M22.
(a)
(i)
(dismantle and) remove radioactive waste / materials / fuels
accept nuclear for radioactive
do not accept knock down / shut down
1
(ii)
increases it
do not accept it has a negative effect
1
(b)
(i)if efficiency is not mentioned it must be implied
answers in terms of energy
generated only gains no credit
K most efficient
or
M least efficient
accept K and / or L are more efficient than M
1
(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 / energy
accept other ways of generating energy may be expanded
•
do not know future energy / electricity demands
accept we may become more energy efficient
•
may be new uses for uranium
2
[6]
M23.
(a)
(i)
gas
1
(ii)
one variable is categoric, the other is continuous
1
(iii)
fuel is not burned
accept nothing is burned
do not accept they don’t use fossil fuels
1
(b)
(i)
boiler
1
steam
1
turbine
1
generator
1
(ii)
any one from:
•
wind
accept wind turbines
•
waves
•
tidal
accept tide
•
geothermal
•
solar
accept the Sun / sunlight
accept solar panels / cells
do not accept light
•
falling water
accept hydroelectric
do not accept water
do not accept any named biofuel
1
(iii)
18 000
allow 1 mark for showing a correct method
ie 36 000 000 ÷ 2 000
an answer of 0.018 gains 1 mark
2
[10]
M24.
(a)
(i)
4
allow 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 labelled
electrical / electricity / useful
1
(iii)
any one from:
•
time of day / year
•
position of solar cells
•
angle of solar cells (to the Sun)
•
latitude
•
cloud cover
•
solar cells covered in dust / dirt
accept charger for solar cells
accept any reasonable suggestion that would lead to a change in
intensity of sun(light)
the weather is insufficient
do not accept any physical changes to the charger eg area
1
causes a change in intensity of sun(light)
accept brightness for intensity
accept a description of the reduction of intensity
1
(b)
any one from:
•
to check reliability / validity / accuracy
•
to avoid bias
1
(c)
any two from:
•
produce no / less (air) pollution
accept named pollutant
accept produces no waste (gases)
•
energy is free
accept it is a free resource
do 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
[8]
M25.
(a)
(i)
decommissioning
1
(ii)
level of radiation or radiation dose (to workers) decreased
accept the isotope / cobalt(-60) has decayed (a lot)
accept the isotope / cobalt(-60) has decayed in 2 half lives
accept exposed to less radiation
do not accept no radiation left
1
less hazardous / dangerous (to workers' health)
accept safer
do not accept there is no hazard
accept allows reactor to cool (down)
an answer of radiation levels decrease by 75 % or drops to 25 %
gains 2 marks
1
(b)
(i)
more in favour
or
fewer against
quoting figures alone is insufficient
do not accept it increases
ignore any reasons given
1
(ii)
any one from:
•
sample too small
•
do not know how many (people) were asked
•
different people asked (in different years)
•
sample not representative (of population)
•
people did not understand the questions
•
do not know who carried out the surveys
do not accept they are biased unless acceptable reason for bias
given
•
do not know if surveys asked same questions
1
(iii)
any one from:
•
no / less pollutant gases produced
accept a named gas
accept does not contribute to global warming
•
reliable source (of energy / electricity)
•
running out of fossil fuels
accept a named fossil fuel
•
conserve fossil fuels
accept fossil fuels won’t have to be used
•
meet increasing demand
•
less reliance on imported fossil fuels / electricity
accept named fossil fuel
•
concentrated energy source(s)
•
lower transportation costs for fuel
•
to replace old nuclear power stations
ignore references to efficiency / job creation / local economy /
selling electricity
1
(c)
economic issues
1
[7]
M26.
(a)
(i)
kinetic
accept KE
do not accept movement
1
(ii)
0.75
allow 1 mark for correct substitution ie
or
75 %
an answer 0.75 % or 0.75 with a unit gains 1 mark only
an answer 75 with or without a unit gains 1 mark only
2
(b)
any one from:
•
large areas of land are flooded
uses 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 neutral
very noisy is neutral
1
(c)
(i)
system of cables and transformers
both required for the mark
accept power lines / wires for cables
ignore reference to pylons
inclusions of power stations / consumers negates answer
1
(ii)
less energy loss / wasted (in the cables)
accept heat for energy
do not accept no energy loss
do not accept electricity for energy
1
as the cables are shorter
1
[7]
M27.
(a)marks are awarded only for the reason but must match the
ringed answer
for both marks a MAYBE answer should include
a YES and NOresponse answers in terms of the sources being
renewable or
non-renewable are insufficient
any two from:
YES answers may include:
•
wind produces no pollutant gases
accept wind burns no fuel
accept CO2 / SO2 / oxides of nitrogen / greenhouse gas for
pollutant gases
•
nuclear produces no pollutant gases
accept nuclear burns no fuel
•
(burning) gas does not produce SO2
accept gas does not cause acid rain
do not accept they don’t / none produce pollutant gases
NO answers may include:
•
nuclear produces radioactive waste
•
(burning) gas produces CO2 / pollutant gases / air pollution
accept contributes to global warming / greenhouse effect
2
(b)
nuclear power stations use a non-renewable fuel
accept uranium / plutonium is non-renewable
do not accept some are unrenewable
1
[3]
M28.
(a)
kinetic
1
(b)
Z
1
(c)
(i)
generates a lot more energy / electricity / power
need fewer conventional large-scale hydroelectric power
stations is neutral
or
can supply (energy / electricity / power) to more homes
1
(ii)
Large areas of land are flooded.
1
(d)
(i)
National Grid
this answer only
1
(ii)
less energy / heat loss (from the cables)
accept wasted for loss
accept answers in terms of fewer transformers needed
do not accept less electricity lost / wasted
do not accept no energy lost
1
(e)
any one from:
•
fewer rivers (suitable for generators)
•
less mountainous (so rivers fall smaller distances)
accept answers in terms of difficulty linking villages and towns to
grid (in Nepal)
accept answers in terms of more isolated communities
accept answers in terms of UK having more resources for largescale power stations
1
[7]
M29.
(a)
(i)
solar and wind
both required for mark either order
1
(ii)
37(%)
accept their two sources in a(i)
correctly added as an error carried forward (ecf)
1
(b)
A
1
(c)
gas is non-renewable
do not accept they are not all renewable
statements such as gas produces CO2 is neutral
1
[4]
M30.
(a)
can be replaced as fast / faster than it is used
accept will not run out
can be used again negates this mark
1
(b)
any one from:
•
reduce demand on power stations / National Grid (system)
•
to increase the amount of electricity generated (from renewable energy)
•
to conserve fossil fuels
accept use less fossil fuels
•
plenty of animal waste / fuel (available)
accept so animal waste can be used usefully
accept to save money / sell the electricity
produces less harmful gases / SO2 is insufficient
better for environment is insufficient
1
(c)
60 (months) / 5 (years)
ignore any unit given
1
(d)answers must be in terms of the biogas generator
any two from:
•
reliable energy source
or
does not depend on the weather
accept works all of the time
•
uses up waste products
accept animal waste readily available
•
not visually polluting
•
concentrated energy source
•
quieter
ignore it is renewable
do not accept generates more electricity (than wind turbine)
2
[5]
M31.
(a)
(i)
energy from hot rocks in the Earth
accept heat that occurs naturally in the Earth
accept steam / hot water rising to the Earth’s surface
accept an answer in terms of the energy released by radioactive
decay in the Earth
heat energy is insufficient
1
(ii)
water is pumped / moved
1
up (to a higher reservoir)
this mark point only scores if first mark point is awarded
1
(b)
Marks awarded for this answer will be determined by the Quality of Written
Communication (QWC) as well as the standard of the scientific response.
Examiners should also refer to the Marking Guidance and apply a ‘best-fit’
approach to the marking.
0 marks
No relevant content
Level 1 (1-2 marks)
There is a brief description of at least one advantage or disadvantage for
either the planned wind turbines or the suggested electricity power link.
Level 2 (3-4 marks)
There is a description of advantages and disadvantages for
either the planned wind turbines or the suggested electricity power link.
or
A description of the advantages or disadvantages for both the planned
wind turbines and the suggested electricity power link.
Level 3 (5-6 marks)
There is a clear and detailed description of at least one advantage and
one disadvantage for both the planned wind turbines and suggested
electricity power link.
examples of the points made in the response
Offshore wind turbines
advantages
•
renewable (energy resource)
•
low running costs
•
energy is free
•
no gas emissions (when in use)
accept a named gas eg CO2
accept no fuel is burned
accept less dependent on fossil fuels
•
land is not used (up)
disadvantages
•
unreliable – accept wind does not always blow
ignore references to destroying or harming habitats
•
hazard to birds / bats
•
visual pollution – do not accept noise pollution
do not allow if clearly referring to onshore wind turbines
do not accept spoils landscape
•
difficulty of linking turbines to the National Grid
•
large initial cost
•
difficult to erect / maintain
accept a lot of maintenance needed
•
CO2 emissions in manufacture (of large number of turbines)
Suggested Link
advantages
•
income for Iceland
•
using Iceland’s (available) energy (resources)
accept using (Iceland’s) renewable energy (resources)
do not accept reduce the amount of Iceland’s wasted energy
•
provide electricity when wind does not blow / reliable
•
provide electricity at times of peak demand
•
even out fluctuations in supply
•
excess electricity from Britain (windy days) to Iceland and used to pump water up to
store energy
•
Britain less dependent on fossil fuels
accept Britain needs fewer (new) power stations
accept conserves fossil fuels
disadvantages
•
large initial cost
accept expensive (to lay cables)
•
power loss along a long cable
•
(engineering) difficulties in laying / maintaining the cable
accept difficult to repair (if damaged)
6
[10]
M32.
(a)
gas (burning)
1
(b)
(i)
(transmission) cables and (step-up and step-down) transformers
if transformers are named ie step-up transformer then both step-up
and step-down must be given
mention of power station or consumer negates mark
1
(ii)
voltage
1
more efficient
1
(c)
increase
1
[5]
M33.
(a)
9
allow 2 marks for power = 1400 (kW)
if a subsequent calculation is shown award 1 mark only
or
allow 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 mark
ignore reference to pylons
inclusion of power stations / consumers negates the mark
wire(s) is insufficient
1
(ii)
(uses step-up transformer to) increase pd / voltage
accept (transfers energy / electricity at) high voltage
or
(uses step-up transformer to) reduce current
accept (transfers energy / electricity at) low current
ignore correct references to step-down transformers
1
(c)
build a power station that uses a non-renewable fuel or biofuel
accept a named fuel
eg coal or wood
or
buy (lots of) petrol / diesel generators
1
stockpile supplies of the fuel
accept fuel does not rely on the weather
or
fuel 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)
or
when other methods fail
or
when it is needed
answers in terms of using other forms of renewables is insufficient
1
[7]
M34.
(a)
(i)
any one from:
•
produces no (air / atmospheric) pollution
accept named pollutant eg CO2
accept no harmful gases
accept produces no emissions
accept does not add to global warming
environmentally friendly is insufficient
•
energy (source) is free
accept no fuel costs
accept the wind / it is free
1
(ii)
any one from:
•
waves
•
tides
•
falling water
accept hydroelectric
do not accept water (flow)
•
solar
accept Sun / sunlight
accept solar panels / cells
•
geothermal
•
biofuel / biomass
accept a named biofuel
1
(b)
(i)
3000 (kilowatts)
accept 3 megawatts / MW
accept 3 000 000 watts / W
1
(ii)
(average) wind speed below 6 m/s
answers giving a wind speed greater than 3 but less than 6 m/s
gain both marks
allow 1 mark for calculating the output as 500 kW (maximum)
and
allow 1 mark for wind speed too low or wind not strong enough
do not accept wind above 25 m/s
do not accept the turbines are frozen
2
(iii)
A small amount of nuclear fuel generates a large amount of electricity.
both required
Nuclear power stations do not depend on the weather to generate electricity.
1
[6]
M35.
(a)
(i)
any one from:
•
produces no (air / atmospheric) pollution
accept named pollutant eg CO2
accept no harmful gases
accept produces no emissions
accept does not add to global warming
environmentally friendly is insufficient
•
energy (source) is free
accept no fuel costs
accept the wind / it is free
1
(ii)
any one from:
•
waves
•
tides
•
falling water
accept hydroelectric
do not accept water (flow)
•
solar
accept Sun / sunlight
accept solar panels / cells
•
geothermal
•
biofuel / biomass
accept a named biofuel
1
(b)
(i)
3000 (kilowatts)
accept 3 megawatts / MW
accept 3 000 000 watts / W
1
(ii)
(average) wind speed below 6 m/s
answers giving a wind speed greater than 3 but less than 6 m/s
gain both marks
allow 1 mark for calculating the output as 500 kW (maximum)
and
allow 1 mark for wind speed too low or wind not strong enough
do not accept wind above 25 m/s
do not accept the turbines are frozen
2
(iii)
A small amount of nuclear fuel generates a large amount of electricity.
both required
Nuclear power stations do not depend on the weather to generate electricity.
1
[6]
E1.
E2.
This question was well answered.
(a)
A common error was to misread the data, giving the answer ‘coal’ because the bar was
the longest.
(b)
The unpredictable nature of the wind was well understood but fewer candidates were able
to produce a suitable explanation of the reason for the reliability of fuel-burning power
stations.
(c)
Most candidates had the right idea although a significant number simply repeated the
stem of the question.
This question was generally well answered.
Answers to part (a)(iii) contained a lot of errors. Common mistakes involved the idea of
spreading electricity round the country better or making sure there was enough to go round.
Many candidates think that voltage had to be high in the cables so that it can be shared by all
the consumers.
The answer to part (b) was well known. The few candidates that did not gain credit had not read
the question properly and gave answers in terms of fossil fuels running out.
In part (c) reasons against wind farms were better known than arguments in favour of wind
farms. In part (c)(i) most candidates made at least one acceptable point but some candidates
only talked vaguely about wind power being environmentally friendly without giving any
examples and/or that wind power is free once the wind farm has been built. In part (c)(ii) the
majority of candidates made two good points. The most common answers included visual
pollution, noise pollution and the unreliability of wind. A significant number of candidates
referred to bird related problems.
E3.
Most candidates correctly chose coal in part (a).
Part (b) was well answered with most candidates choosing the correct two responses. It was
pleasing to note that very few candidates selected more than two answers.
Part (c)(i) was well answered by the better candidates but the weaker candidates produced
vague and incorrect answers, such as “because there is very little carbon dioxide in the air”.
Some candidates described how a wind turbine worked rather than why there was no carbon
dioxide produced. In part (c)(ii) the majority of candidates scored at least one mark with many
scoring both. Most responses were in terms of visual pollution, noise pollution, reduction in
property values and unreliability. However an alarming number of candidates believed that
wind-powered generators generate wind, and were thus talking about the danger of all the crops
being blown away by the huge winds that would be generated.
E4.
In part (a) most candidates could score 2 out of the 4 marks. Surprisingly few candidates
knew the voltage of the mains.
In part (b)(i) only the better candidates realised that the waste energy would go into heating the
air. An alarming number of candidates thought that the air would become radioactive, electrified,
polluted with carbon dioxide or filled with thick black smoke. The most common incorrect
answer was simply that it ‘pollutes the air’. In part (b)(ii) just over half of all the candidates made
the correct choice.
E5.
Part (a) was not well answered with almost 50% of candidates scoring no marks. Many
candidates wrote negatively about fossil fuels rather than about the merits of nuclear fuel. There
were many vague comments about a lot of energy, with the stronger candidates being able to
relate this to the amount of fuel being used. Some candidates wrote about reliability but some
did not gain credit due to the vagueness of their answers.
The vast majority of candidates gained no credit in part (b) most ignored the fact that the waste
was buried deep, or that it would be in any way contained.
In part (c) some candidates did not use the information they had been given and others ignored
the question’s emphasis on the power companies. Many candidates did not distinguish between
biofuels and electricity, thinking the power company would be selling the biofuels. The idea of
carbon neutral was well identified by stronger candidates, but the weaker ones did not appear to
be aware that burning biofuels also gives rise to carbon dioxide emission. A large number of
candidates (40%) were unable to use any of the information presented to them and gained no
credit at all.
E6.
(a)
(b)
(c)
E7.
(i)
Most candidates correctly identified renewable energy as a source which does
not run out. Some candidates continued to say that it was replaced as quickly as, or
more quickly than, it was used. The most frequently seen incorrect answer was to
say that the source could be used again.
(ii)
A well answered question with most candidates able to successfully identify two
renewable energy sources. If the mark was lost it was mostly for including solar
(which was given in the question) or for simply using the word water.
(i)
Whilst the majority of candidates correctly selected the maximum energy input at an
angle of 30°, few responded in terms of the pattern of increase to and decrease
from this maximum.
(ii)
Some candidates completed the calculation correctly to obtain all 3 marks. Most
candidates made a start on the calculation but common mistakes were to use the
average energy input rather than the maximum, to overlook the area of the solar
cells, or to divide the energy input by 0.15 instead of multiplying.
Most candidates were able to successfully make the link between the amount of energy
required and that provided by the solar cells, realising that the National Grid would be
needed to supply the shortfall. A small number of candidates evidently did not know what
the National Grid was and some thought the purpose of remaining connected was to
monitor the household use of electricity. Some gave the impression that they thought the
National Grid was the only way to get electricity or that this was needed to ensure safety
and/or the correct voltage.
(a) Most candidates correctly chose gas and oil as being the two energy sources likely to
be used up first. A few candidates ignored the rubric and selected more than two energy
sources.
(b)
Many answers to this question were very vague, such as “they both have turbines”. The
correct response required a reference to a step in the process.
(c)
A well-answered question, with the majority of candidates obtaining the correct answer of
140 °C. Some candidates misread the scale and gave a wrong answer of 40 °C.
(d)
Candidates usually realised that one advantage of geothermal energy was either that it
saved using fossil fuels or that it is a renewable energy source. Some candidates simply
restated the question, saying that the scientists would tell the government that this method
could generate one quarter of the world’s electricity.
E8.
Foundation tier
(a)
(b)
(i)
The majority of candidates did not appear to understand what is meant by the
termefficient in a scientific context. Many were quoting an ‘everyday’ sense of the
word, such as ‘reliable’, ‘gets the job done’ or ‘works quickly’.
(ii)
Although a few of the better candidates knew that the current was decreased, hardly
any realised why. Many candidates thought that the cables were covered with an
insulating material to prevent heat loss, whilst others thought that the National Grid
stored the heat energy and used it to heat people’s homes.
(i)
A minority of candidates correctly stated that the reason was for the purpose of
comparison or to act as a control. Most candidates simply stated that it was to make
it a fair test.
(ii)
Again, a common response that gained no marks was ‘to make it a fair test’. Others
simply repeated the question by stating ‘so that they know how many children were
studied’.
(iii)
Most candidates did not score any credit. Weaker candidates, perhaps reading the
stimulus passage too quickly, said that the children had developed leukaemia
because their parents were unable to control them.
(iv)
Most candidates opted to tick the second box, and were able to support this choice
with a sensible reason. Those candidates who ticked the first box were less
successful at providing a satisfactory reason.
Higher tier
(a)
(b)
(i)
Many candidates did not appear to understand what is meant by the term efficient in
a scientific context. Quite a number of answers referred to no energy being wasted.
(ii)
Many candidates realised that transformers played a part, but either did not know
the specific details or wrote vague statements such as ‘it steps up the voltage and
then steps it down again’. The majority answered correctly that the voltage was
increased, but many failed to link this with a reduction in current, thereby reducing
energy loss as heat.
(i)
It was pleasing that many candidates understood the need for a control.
E9.
(ii)
Whilst a large number of candidates realised that this was linked to reliability, the
majority of candidates confused this term with ‘accuracy’ or ‘fair test’. Of those who
used the correct word, most answered correctly in terms of the reader making a
judgement about the reliability of the data, or that a larger sample would make the
results more reliable.
(iii)
This was answered better, with a majority of candidates scoring both marks.
(iv)
Most candidates opted to tick the second box, and were able to support this choice
with a sensible reason. Those candidates who ticked the first box were less
successful at providing a satisfactory reason.
(a) Some candidates were not reading the question with sufficient care and thought that
the question read “What could a government scientist do …” This interpretation led them
to answers such as “Give a slide show” or “Produce a leaflet”. Of the candidates who were
able to provide reasons, most were able to suggest that fossil fuels are running out. Many
answers however were vague; examiners frequently saw answers such as “It is bad for
the environment”
(b)
E10.
Usually well answered, although some candidates used the same letter twice.
(a) This question was generally well answered though some candidates had misread the
key and confused hydro with oil. Some candidates only gave a simple response about the
decrease in oil and had not read the question well enough to spot that it contained a
plural.
(b)
(i)
Surprisingly only just over half of the candidates could correctly name the process.
Most incorrect answers gave the name of a chemical process.
(ii)
Only the better candidates were able to gain full credit for a clear explanation of the
process. Many candidates failed to gain any credit for omitting the word ‘steam’
and/or giving descriptions of ‘heat’ turning turbines. Some candidates tried gave an
explanation of nuclear fission, clearly having not read the question.
(iii)
Few candidates gained both marks. The majority gained one mark for stating a ‘no
CO2 released’ type answer or that nuclear power stations are reliable. The most
common incorrect responses were ‘nuclear fuel is efficient’/ ‘nuclear fuel will not run
out’/ ‘nuclear fuels produce more energy’/ ‘nuclear fuel is renewable’. A worrying
proportion of candidates talked about burning the nuclear fuel.
(iv)
This was well answered with the majority of candidates knowing that the waste was
radioactive. Extra information was often given such as the effect on tissue, food
chains, etc and the long half-life. Weaker responses referred to the waste as
reactive or were concerned with greenhouse gases or acid rain.
(c)
E11.
Many good answers were seen. The second mark was often lost because of a reference
to CO2 destroying the ozone layer or simply repeating the given phrase ‘climate change’.
(a)
(b)
(i)
Most candidates were able to identify France as being the country with the
smallest amount of standby energy.
(ii)
Few candidates were able to offer a sensible suggestion as to why an average value
of the standby energy is used.
(i)
The majority of candidates were able to spot the correct relationship and gain credit.
However a significant minority of candidates clearly misunderstand the term
‘standby energy’ believing it to be some kind of reserve store of energy that could be
used if the mains supply failed.
(ii)
Only the better candidates were able to score both marks for this question. Many
answers were very vague and simply talked about there being less pollution, without
specifying what type of pollution would be reduced. There were many answers that
talked about the general benefits of conservation, and the fact that the coal would
one day run out did not answer the question that asked for an explanation of how
the environment would benefit.
(c)
Surprisingly only half the candidates identified the joule as being the usual unit of energy.
(d)
(i)
It was encouraging to see that a large number of candidates were able to complete
the calculation correctly and earn all three marks available. Many of the weaker
candidates were able to substitute the correct numbers into the equation that was
given, but then failed to complete the arithmetic correctly nevertheless, they could
still score marks by showing the correct method.
Some candidates converted their answer into pounds, but then failed to put a pound
sign in front of the number. This lost them a mark as the units ‘pence’ had already
been put into the answer line for them.
(ii)
E12.
(a)
Most candidates correctly identified an advantage of using nuclear fuels.
(i)(ii) Surprisingly less than half of the candidates realised that the wind is an
unreliable energy source and that the tides are a predictable energy source. A
significant proportion of candidates thought that both were a constant energy
source.
E13.
(b)
The great majority of candidates were able to state that a new tree or trees must be
planted to replace the one that had been chopped down. Some candidates however
misread the question and talked about what must happen to the tree after it had been
chopped down, eg being made into paper.
(c)
The majority of candidates were able to interpret the graph correctly, and so deduce that
the percentage is most likely to be greater than 4 %.
Nearly all candidates knew that the network is called the National Grid, and most could
identify the appropriate transformers and, most knew that, in a step-down transformer, the p.d.
across the primary coil is more than the p.d. across the secondary coil.
E14.
(a) Some candidates had problems reading all 4 values from the graph correctly, but did
gain one mark for showing correct working. A significant number of candidates, having
read the values correctly, were unable to calculate a proportion.
(b)
(c)
E15.
(i)
This was generally well answered. The most common one-mark answers chose
student B but failed to explain the link between fossil fuels and carbon dioxide
emissions.
(ii)
This was very well answered with candidates showing a practical understanding of
the problem. The most common response being ‘don’t leave appliances on standby’.
(i)
Whilst many candidates were able to score one or two marks for picking out a
couple of significant features of the graph, detailed answers were not common. A
number of candidates failed to gain any credit for answers which tried to describe
the action of a wind turbine. Some candidates seemed to think that because the line
went down after 25 m/s, this was showing that the wind speed was falling. A cause
for concern was the idea that it is the wind turbines that create the wind!
(ii)
This was well answered by many candidates, the most common error being a
general description of wind turbines such as noisy and an eye-sore.
(a)
(i)
The majority of candidates were able to offer the name of a suitable renewable
energy resource. A few candidates were not sufficiently specific in their answers,
and wrote answers such as ‘water’. A significant minority of candidates simply
repeated the stem of the question and gave the answer as wind.
(b)
(ii)
Most candidates realised that using less fossil fuel will decrease the amount of
carbon dioxide emitted.
(i)
A large number of candidates do not appear to know the difference between am and
pm and were therefore describing what happened to the demand during the
evening. An equally large number of candidates also thought that the question
asked them to describe why the demand varied rather than how the demand
varied. They were therefore going into great detail about how people were getting
up for work after 4 am and switching on their kettles.
Of those candidates who did attempt to describe how the demand varied between
4.00 and 10.00 am many only obtained one of the two marks. This was because
they had failed to describe what the graph showed in sufficient detail. When asked
to describe what a graph shows, it is always a good idea to quote some figures from
the graph, particularly for points of inflection.
(ii)
E16.
Only the better candidates seemed to realise that a gas-fired power station would
have the shortest start-up time.
(a) Most candidates correctly stated that solar cells are designed to transform light
energy into electrical energy. The most common mistake was to state that they transform
heat energy into electrical energy.
(b)
(i)
The majority of candidates could substitute the correct numbers into the correct
places in the equation. However, some candidates then found that they could not
cope with a fraction where the denominator was larger than the numerator; they
therefore inverted the fraction and ended up with the answer 5 instead of 0.2. It is
possible that some candidates did not use a calculator in the examination.
Some candidates tried, unnecessarily, to express the answer as a percentage.
Those who correctly answered 20% gained both marks; those who erroneously
stated it to be 0.2% were only awarded one mark.
(c)
(ii)
Most candidates correctly stated that the energy that is not usefully transferred is
wasted.
(i)
Most candidates correctly stated that either the fuel cells were to act as a backup for
the solar cells, or that this enabled the aircraft to fly at night or when there was
insufficient light.
(ii)
Most candidates were able to state that burning fuels releases gases such as
carbon dioxide into the atmosphere. Candidates whose answers were very vague
such as “it reduces pollution” were not awarded a mark.
(iii)
Many candidates believed that such an aircraft would be able to fly into space or be
used to visit the moon. Another common mistake was to misread the question and
instead of suggesting a possible use for the aircraft, some candidates were giving
an advantage of this aircraft over conventional passenger jets.
E20.
(a)
(b)
E21.
E22.
(i) Surprisingly only just over a third of candidates scored this mark, ‘wave’ and
‘hydro-electric’ were the most common incorrect answers.
(ii)
Many candidates were able to score two marks for sensible responses. Marks were
often lost because of terms such as ‘eco-friendly’, ‘green energy’ ‘not harmful to the
environment’ etc, which should have been expanded on in terms of carbon dioxide
emissions or air pollution to score a mark.
(i)
This was poorly answered with only just over a third of candidates giving an
acceptable reason. Although the information given had said that the new scheme
would produce enough electricity for both towns, many answers indicated that
candidates had not read this.
(ii)
There were many good answers to this question with just under half of the
candidates scoring both marks.
(a) Most candidates could score well on this question, with just over half of the
candidates scoring full marks. The most common error was to link ‘The sea is always too
rough’ to ‘Tides’ as the energy source, rather than linking it to ‘Waves’.
(b)
Most candidates realised that all the energy sources listed were renewable sources.
However describing them as ‘natural’ sources was a common answer that did not gain a
mark, and some candidates gave answers that were even more vague, such as
‘environmentally friendly’.
(c)
Nearly three fifths of candidates correctly realised that one disadvantage of a hydroelectric
power station is that large areas of land are flooded. A significant number of candidates
chose ‘polluting gases are produced.’.
(a)
(ii)
(i) There were few correct answers, most candidates referred to closing down the
power station but few discussed the removal of radioactive material from the site.
A mix of answers with many candidates attempting to give a reason.
(b)
E23.
A large number of answers failed to mention the efficiency, which is what the
question was about. Of those candidates which did, some compared the efficiency
of the three power stations to each other, some discussed the change in efficiency
of each power station over the years, but very few gave both answers.
(ii)
A large number of vague answers were seen, such as ‘anything could happen in the
future’ or ‘we can’t predict that far into the future’. Just over half of the candidates
scored at least 1 mark.
(a)
(b)
E24.
(i)
(i) Almost all candidates correctly identified gas as being the fuel that produces the
smallest amount of carbon dioxide.
(ii)
Disappointingly less than half of the candidates realised that one variable is
categoric and the other is continuous.
(iii)
A poorly answered question with few candidates realising that nuclear power
stations do not burn any fuel.
(i)
A good response to this question, with many candidates obtaining all 4 marks.
Where marks were lost, it was generally caused by confusing the turbine with the
generator.
(ii)
Surprisingly only just over half of the candidates were able to name a suitable
energy source, usually wind or solar power. Many candidates failed to read the
question with sufficient care and named another biofuel. A significant number of
candidates named a fossil fuel or gave nuclear.
(iii)
A good response to this question, with many candidates obtaining the correct
answer. Some candidates however used the power of the power station in MW but
kept the figure for the average power used in the home in watts ending up with a
fraction of a home. Other candidates multiplied the figures ending up with an answer
of 72 000 000 000 homes. It is unfortunate that such candidates do not realise how
unrealistic these figures are.
(a)
(ii)
(i) Less than half of the candidates answered this correctly. Many were unable to
transpose the equation correctly.
Only about a third of candidates were able to draw something resembling a Sankey
diagram and label it appropriately. Whilst the majority of candidates obviously had
some idea that a Sankey diagram had some arrows going in different directions,
some drew a picture of solar cells, and over a tenth did not attempt the question.
(iii)
This was answered reasonably well, with over three quarters of candidates gaining
at least one of the two marks, usually for realising that a change in intensity of the
sunlight would affect the time taken to charge the battery. However, less than half of
these went on to score the second mark by giving a factor which would change the
intensity.
(b)
This question was correctly answered by the majority of candidates. However, many
seem to have a dim view of company scientists, indicating that they would lie or falsify
results.
(c)
Nearly all candidates gained at least one mark, with more than half scoring both. The
most common answers were that the Sun is a renewable resource and that solar cells do
not produce pollutant gases.
E25.
(a)
(ii)
(i) The majority of candidates opted for the wrong answer ‘decontaminating’ rather
than the correct answer of ‘decommissioning’.
This proved to be a difficult question for most candidates, with less than a tenth
achieving both marks. The most common mistake was to argue that, as the half-life
was 5.3 years, this would mean that in 10.6 years all radiation would have ceased.
Many of the weaker candidates treated the term‘half-life’ rather too literally, and
would talk about the isotope being ‘dead’ after 11 years. Another common
misunderstanding was to talk about the half-life reducing as time went on. Some
candidates even thought that the term‘half-life’ referred to the life span of the
workers.
(b)
(c)
(i)
Most candidates realised that the percentage of people in favour of nuclear power
stations had increased.
Some candidates simply wrote‘it went up’, without specifying what‘it’ was.Some
candidates failed to say how the percentages had changed, but instead suggested a
reason why the figures might have changed.
(ii)
The better candidates were able to suggest a sensible reason as to why some
people might consider the results to be unreliable. Many candidates, however,
thought that the results were unreliable simply because there was no data for the
intervening years. Others suggested that the results could be biased, but offered no
suggestion as to why they might be biased.
(iii)
Few candidates were able to offer an acceptable reason as to why more nuclear
power stations should be built. Most of the reasons offered were not specific to the
building of a nuclear power station, eg‘to bring more jobs to the area’.
Most candidates correctly identified this as being an economic reason.
E26.
(a)
(ii)
(i)
This was well answered.
The majority of candidates were able to substitute correctly into the given equation.
Mistakes made subsequently were to do the arithmetic incorrectly, or to give a
wrong unit with a correct numerical answer, eg 75 J or 0.75 %.
(b)
Few candidates scored this mark. A common insufficient answer was to say that it would
take up a lot of land, without going on to explain the consequences. Few candidates
seemed to realise that scaling up by a factor of 100 000 would require the area to be
flooded.
(c)
(i)
As a simple recall of knowledge question it was surprising that very few candidates
were able to give the correct answer. Common misconceptions included the idea
that pylons carry the electricity; that the power station or consumer is part of the
National Grid.
(ii)
Despite the given information stating that the electricity from the micro-system was
transferred to local homes via a transformer, a large number of answers stated that
no transformers would be needed, indicating that many candidates had failed to
read the question carefully.
(a) The majority of candidates opted for the ‘no’ answer and were able to identify that
gas, as a fossil fuel, would release carbon dioxide when burned. Of those who identified
‘nuclear’ waste as not being environmentally friendly, many failed to say that this was
because it was radioactive. Over half of the candidates gave incomplete answers or such
vague responses that they scored no marks.
E27.
(b)
E28.
Surprisingly, only just over half of the candidates were able to identify that nuclear power
stations did not use a renewable source. There were many vague answers stating ‘they
are not all renewable’.
(a) Most candidates correctly chose kinetic energy, the most common wrong answer
being electrical.
(b)
Most candidates correctly chose diagram Z.
(c)
(d)
(e)
E29.
(i)
This question was well answered by the majority of candidates with just over three
quarters of candidates scoring the mark.
(ii)
Surprisingly only the better candidates correctly chose ‘large areas of land are
flooded’. The most common answer was ‘A constant flow of water is needed’.
(i)
Just over a third of candidates stated that this was the National Grid.
(ii)
Only the better candidates were able to relate the use of short cables to the idea of
energy losses. Common incorrect answers often referred to electricity being lost or
to electricity travelling faster in shorter cables.
This question was answered well by the majority of candidates.
(a)
(ii)
(i) The majority of candidates correctly identified wind and solar as being the two
energy sources that do not produce any polluting gases.
Most candidates correctly worked the percentage as 37%.
(b)
About two-thirds of candidates correctly identified graph A as the one most likely to
represent the output from a wind turbine.
(c)
Almost half of the candidates were able to state that gas is not a renewable energy
source. The other half missed the point that there was an incorrect statement in the report,
and instead offered their opinion as to why any or all of these power stations should not
be built. Often such arguments were based on the pollution from gas burning power
stations.
(a) Many responses stated that a renewable source can be ‘used again and again’ and
therefore did not gain any credit. The idea of a source that ‘does not run out’ or that it is
‘replaced as fast as it is used’ was only presented by a small minority of students.
E30.
(b)
Many vague assertions such as ‘better for the environment’ or ‘eco-friendly’ gained no
credit. Other students thought that the waste consisted of ‘dead animals’. Most correct
responses came from the idea of the availability of animal waste or the fact that the farmer
“saves money” in this process.
(c)
Over three fifths of students scored this mark, although the fact that units were ignored by
examiners was a saving grace for some.
(d)
Surprisingly only three fifths of students managed to score at least one mark for this
question. Those that did not usually discussed the advantages and disadvantages of wind
turbines but made no reference to biogas generators. Some students thought that the
products of combustion (carbon dioxide and water) could be used on the farm.
E31.
(a)
(ii)
(b)
E32.
(i)
Few students appear to understand what geothermal energy is. Just over a
tenth of students did not attempt this question.
Most students that attempted this question simply described a hydroelectric system,
missing the point about this being a pumped storage hydroelectric system. Many
students thought that it was the energy or the electricity that was being pumped;
others thought that it was the pump that stored the energy. Almost a quarter of
students did not attempt this question.
This was the 6-mark Quality of Written Communication (QWC) question in which students
had to discuss the advantages and disadvantages of two proposals: building off-shore
wind turbines or laying a cable to connect to renewable resources in Iceland. The best
responses came from those who spent a couple of minutes making a grid to show the
pros and cons of each in note form. They then used these notes to construct a full
response. Most students could provide advantages and disadvantages for the wind
turbines, but rather fewer responses successfully referred to the link to Iceland. Some
students had clearly not read the question properly, and had failed to notice that the wind
turbines were off-shore. Their answers therefore related to the countryside being ruined
and land taken up with thousands of large turbines. There were many objections to the
underwater cable on the grounds that ‘electricity and water don’t mix’. Just under a tenth
of students failed to make an attempt at this question, however the majority wrote at
length.
(a) Few students were able to recall that gas-fired power stations have the shortest startup;time. Almost a fifth of students did not even attempt an answer.
(b)
(c)
(i)
Very few students realised that the National Grid comprises of step-up and stepdown transformers, as well as the transmission cables. Most thought that it was
simply the transmission cables. A significant number of students included either the
power station or consumer or even both
(ii)
Just under half of students were able to score both marks for knowing what a stepup transformer does.
Most students realised that the trend shown on the graph suggests that the percentage
will increase over the next ten years.
E33.
(a) Students made heavy weather of this calculation, often converting the time into
seconds, and failing to realise that the 5600 kilowatt-hours was the energy rather than the
power. Hence very large values (several hundred thousand), obtained from these
calculations, were quoted as being the wind speed. Even students who correctly
calculated the power output as 1400kW often seemed unable to relate this to the graph to
obtain a corresponding wind speed.
(b)
(c)
E34.
(i)
As with a similar question in last year’s paper, very few correct responses were
given. Transformers rarely featured, but many students seem to think that pylons
carry electricity.
(ii)
Many students knew that transformers were involved here, but answers were often
not specific enough, for instance ‘step up and step down transformers are used’.
Again, answers often failed to be specific enough, for example ‘use another way of
producing electricity’. A significant number of answers referred to using wind turbines,
indicating that students had not read the newspaper extract carefully.
(a)
(b)
(i)
Surprisingly many students did not score this mark. Many students
concentrated on explaining that wind was a renewable energy source, forgetting that
this was given in the stem of the question. Others simply suggested that wind was
‘natural’ or ‘good for the planet’. Students found it difficult to differentiate between
the cost of the wind as an energy source (free) and the cost of electricity from wind
turbines, many imagining that it was free or very cheap.
(ii)
Many students were able to give one example of a renewable energy source, solar
being the most popular. ‘Water’ was not accepted as an energy source unless it was
apparent that the answer referred to ‘falling water’.
(i)
Most students gained this mark.
(ii)
Many students tried to explain the shape of the graph and ignored the question that
they were asked. The students appeared to assume that the horizontal axis
represented time and suggested that the ‘wind started low, gathered speed and then
got so fast that the output dropped to zero – all in 25 seconds’. Others stated that
there was either no wind or its speed was too high and so ‘no power’ would be
generated. However, the question referred to power generation at a lower rate and
so these answers were incorrect. Few students were prepared to give a wind speed
appropriate to the scenario that the question outlined, but a minority were able to
gain one mark for saying that the wind was too low during this time period. There
were frequent references to the turbines freezing or icing up.
(iii)
The majority of students gained this mark.
E35.
(a)
(b)
(i)
Surprisingly many students did not score this mark. Many students
concentrated on explaining that wind was a renewable energy source, forgetting that
this was given in the stem of the question. Others simply suggested that wind was
‘natural’ or ‘good for the planet’. Students found it difficult to differentiate between
the cost of the wind as an energy source (free) and the cost of electricity from wind
turbines, many imagining that it was free or very cheap.
(ii)
Many students were able to give one example of a renewable energy source, solar
being the most popular. ‘Water’ was not accepted as an energy source unless it was
apparent that the answer referred to ‘falling water’.
(i)
Most students gained this mark.
(ii)
Many students tried to explain the shape of the graph and ignored the question that
they were asked. The students appeared to assume that the horizontal axis
represented time and suggested that the ‘wind started low, gathered speed and then
got so fast that the output dropped to zero – all in 25 seconds’. Others stated that
there was either no wind or its speed was too high and so ‘no power’ would be
generated. However, the question referred to power generation at a lower rate and
so these answers were incorrect. Few students were prepared to give a wind speed
appropriate to the scenario that the question outlined, but a minority were able to
gain one mark for saying that the wind was too low during this time period. There
were frequent references to the turbines freezing or icing up.
(iii)
The majority of students gained this mark.