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Transcript 
Name: _______________________________________________
P1 Topic 5 Generation and
Transmission of Electricity
Date:
Time:
Total marks available:
Total marks achieved: ______
Questions
Q1.
* Another way of producing electricity from a renewable source is tidal power.
A dam is built across the mouth of a river.
Tidal water gets trapped behind the dam.
The trapped water is used to generate electricity.
Discuss the advantages and disadvantages of using tidal power rather than other methods of generating
electricity.
(6)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
Q2.
*Some students found this information about an energy saving lamp and a filament lamp that give out
almost the same amount of light.
Describe the advantages and disadvantages of each type of lamp.
(6)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
Q3.
* Some research has been carried out into replacing fluorescent lamp fittings with LED fittings.
The data in the table is taken from the report of a trial using LEDs to light stairwells and corridors in a
large building.
Use the information to discuss the benefits of replacing fluorescent fittings with LED fittings.
(6)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
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Q4.
(a) Electricity costs 20p for each kW h.
The pictures show a domestic electricity meter at two different times.
(i) Calculate the cost of the electricity used between the two readings.
(2)
cost =...........................................................p
(ii) The time between these two readings is 15 hours.
Calculate the average power supplied.
(2)
average power =...........................................................kW
(b) Explain why step-up transformers are used in the transmission of electricity in the National Grid.
(2)
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
*(c) The diagram shows a magnet moving into a coil of wire.
The coil of wire is attached to a sensitive ammeter.
The moving magnet and the coil of wire are producing an electric current.
The size and direction of the current can be changed in a number of ways.
Describe changes that can be made to produce different currents and the effect of each change.
(6)
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
(Total for Question = 12 marks)
Q5.
* The diagram shows a model used to generate electricity from water waves in a tank.
A ball floats on the surface of the water in the tank.
A coil of wire is fixed to the floor of the tank.
A magnet is suspended from the ball inside the coil.
When a wave is sent along the surface of the water the ball moves up and down.
The graph shows the current induced in the coil.
Explain how this current is induced in the coil in the model.
You should refer to the model and to the labelled points on the graph in your answer.
(6)
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Q6.
Distribution of electricity
(a) Scientists say that graph 1 shows an alternating current while graph 2 shows a direct current.
The two graphs differ in several ways.
State the difference between the currents which makes one alternating and the other direct.
(1)
..............................................................................................................................................
..............................................................................................................................................
(b) A transformer is 100% efficient.
It has 200 turns on the primary coil and 3000 turns on the secondary coil. The input voltage is 55 V.
(i) Show that the output voltage is about 800 V.
(3)
(ii) Calculate the current in the secondary coil when the current in the primary coil is 0.50 A.
(2)
current in secondary coil =............................... A
*(c) The diagram shows how electricity produced at a power station is transmitted to distant houses.
Transformers R and S are not 100% efficient.
By using transformers, energy losses in the transmission lines are reduced.
Explain how this reduction is achieved, even though some energy is wasted in the transformers
themselves.
(6)
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Q7.
(a) Eric owns a small farm where chicks are hatched from eggs.
He is considering generating his own electricity to heat and light a barn rather than using electricity from
the National Grid.
This graph shows how the energy output varies with wind speed for two different wind turbines, A and B.
The average wind speed at Eric's farm is 13 mph.
The total heating and lighting in the barn requires 6000 kW h of electrical energy each year.
(i) Use the data in the graph to recommend the best turbine for Eric's barn.
(1)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
(ii) Eric pays 14p per kW h for electrical energy supplied by the National Grid.
Calculate how much he could expect to save each year by using the energy from this wind turbine to
heat and
light the barn.
(2)
..............................................................................................................................................
(iii) Eric looks at the cost of installing the turbine.
State how he should work out the payback time.
(1)
..............................................................................................................................................
..............................................................................................................................................
(iv) The chicks need to be kept warm at all times.
Eric uses halogen lamps to provide heat and light for most of the day.
Eric thinks about changing his halogen lamps for energy saving lamps.
Suggest why this might not actually be a benefit.
(2)
..............................................................................................................................................
..............................................................................................................................................
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*(b) There are several large-scale energy resources which are suitable alternatives to fossil fuels in
some situations.
Two of these alternatives are hydro-electric power and solar power.
Compare hydro-electric power with solar power as energy resources for the large-scale generation
of electricity.
(6)
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(Total for Question is 12 marks)
Q8.
Generating electrical energy
(a) Complete the sentence by putting a cross (
Electrical energy can be measured in
) in the box next to your answer.
(1)
A
B
C
D
amps
kilowatt-hours
volts
watts
(b) Scientists are looking for new ways to produce electricity from renewable resources.
The diagram shows a model of a device to generate electricity from waves.
The coil is fixed to the concrete block.
The magnet can move freely inside the coil.
(i) Explain how this device produces an electric current.
(3)
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(ii) Describe how the device can be altered to increase the electric current.
(2)
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..............................................................................................................................................
*(c) Another way of producing electricity from a renewable source is tidal power.
A dam is built across the mouth of a river.
Tidal water gets trapped behind the dam.
The trapped water is used to generate electricity.
Discuss the advantages and disadvantages of using tidal power rather than other methods of
generating electricity.
(6)
..............................................................................................................................................
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Q9.
The photograph shows a small generator.
When the handle is turned the current produced lights a lamp.
(a) (i) Complete the sentence by putting a cross (
The current produced
) in the box next to your answer.
(1)
A usually comes from a battery
B always has the same frequency
C is always the same size
D is usually alternating in direction
(ii) State the unit in which electric current is usually measured.
(1)
..............................................................................................................................................
(b) (i) Describe what happens inside the generator to produce the current.
(3)
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(ii) State one way in which the size of the current could be increased.
(1)
..............................................................................................................................................
..............................................................................................................................................
*(c) The National Grid is supplied with electricity from large-scale electrical generators.
These generators may be driven using different energy sources.
Compare the use of a non-renewable energy source with the use of a renewable energy source to
produce electricity
for the National Grid.
(6)
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(Total for Question is 12 marks)
Q10.
A dynamo generates an electric current by induction.
Explain what is meant by induction of a current.
(3)
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(Total for question = 3 marks)
Q11.
* There are several large-scale energy resources which are suitable alternatives to fossil fuels in
some situations.
Two of these alternatives are hydro-electric power and solar power.
Compare hydro-electric power with solar power as energy resources for the large-scale generation
of electricity.
(6)
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Q12.
* The first public power station was built in the centre of New York.
It used generators to supply direct current at 110 V. The cables had to go underground and they could
only supply
nearby shops and offices.
The electricity was mainly used for electric light.
The development of alternating current generators led to major changes in the way electricity is
transmitted and used.
Compare the modern National Grid system with the early system in New York.
(6)
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Q13.
(a) The diagram shows a simple generator connected to a lamp.
The magnet is made to spin at a steady speed.
The ammeter gives a reading of 1.5 A.
The voltmeter gives a reading of 6 V.
(i) Calculate the output power of the generator.
(2)
..............................................................................................................................................
(ii) State two changes to the design of the generator that would give a larger output power for the
same speed of rotation.
(2)
..............................................................................................................................................
..............................................................................................................................................
(iii) This generator supplies an alternating current (AC) to the lamp.
Other types of generators supply a direct current (DC).
Describe the difference between charge movement in a direct current and in an alternating current.
(2)
..............................................................................................................................................
..............................................................................................................................................
*(b) The first public power station was built in the centre of New York.
It used generators to supply direct current at 110 V. The cables had to go underground and they could
only supply
nearby shops and offices.
The electricity was mainly used for electric light.
The development of alternating current generators led to major changes in the way electricity is
transmitted and used.
Compare the modern National Grid system with the early system in New York.
(6)
..............................................................................................................................................
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(Total for Question is 12 marks)
Q14.
The photograph shows a small generator.
When the handle is turned the current produced lights a lamp.
* The National Grid is supplied with electricity from large-scale electrical generators.
These generators may be driven using different energy sources.
Compare the use of a non-renewable energy source with the use of a renewable energy source to
produce electricity
for the National Grid.
(6)
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Q15.
* The diagram shows how electricity produced at a power station is transmitted to distant houses.
Transformers R and S are not 100% efficient.
By using transformers, energy losses in the transmission lines are reduced.
Explain how this reduction is achieved, even though some energy is wasted in the transformers
themselves.
(6)
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Q16.
Transformers are used on a small scale in the home and on a large scale in the National Grid.
(i) The transformer for an electric toothbrush charger steps down the mains voltage to 9.0 V.
The mains voltage is 230 V.
The transformer has 690 turns on its primary coil.
Calculate the number of turns on the secondary coil.
(3)
number of turns = ..............................................................................
*(ii) The National Grid transmits electricity around the country.
Explain how using transformers makes the transmission of electrical energy more efficient.
(6)
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Q17.
* An electric fridge is kept cool by a compressor.
The compressor clicks on and off during the day to keep the inside of the fridge at a constant low
temperature.
The table shows some information about two different fridges.
Describe the advantages and disadvantages of each fridge.
(6)
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(Total for question = 6 marks)
Q18.
(a) Complete the sentence by putting a cross (
An electric current is the rate of flow of
) in the box next to your answer.
(1)
A atoms
B charge
C voltage
D watts
(b) An electric kettle is connected to a mains voltage of 230 V.
The current in the kettle is 12 A.
Calculate the power of the kettle.
(2)
..............................................................................................................................................
(c) A television has a power of 400 W.
The cost of 1 kW h of electrical energy is 15p.
Calculate the cost of using the television for 10 hours.
(3)
..............................................................................................................................................
*(d) Some students found this information about an energy saving lamp and a filament lamp that give
out almost the same amount of light.
Describe the advantages and disadvantages of each type of lamp.
(6)
..............................................................................................................................................
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..............................................................................................................................................
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(Total for Question = 12 marks)
Q19.
(a) What is the name of the device used to change the size of an alternating voltage?
(1)
..............................................................................................................................................
(b) A light emitting diode (LED) can only emit light when connected correctly to a potential difference.
Use this information to suggest what happens when this alternating voltage is connected across the
LED.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
(c) A LED lamp has a power rating of 3 W.
The voltage across the lamp is 12 V.
Calculate the current in the lamp.
(3)
current in the lamp =. . . . . . . . . . . . . . . . . . . . .A
*(d) Some research has been carried out into replacing fluorescent lamp fittings with LED fittings.
The data in the table is taken from the report of a trial using LEDs to light stairwells and corridors in a
large building.
Use the information to discuss the benefits of replacing fluorescent fittings with LED fittings.
(6)
..............................................................................................................................................
..............................................................................................................................................
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..............................................................................................................................................
..............................................................................................................................................
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..............................................................................................................................................
(Total for Question = 12 marks)
Mark Scheme
Q1.
QWC
Question
Number
*
Indicative Content
A discussion linking
some of the following
Advantages of tidal
power• renewable
energy source
• reduction in
greenhouse
gases/atmospheric
pollution (compared
to fossil fuel)
• reduces reliance
on fossil fuels
• conserves stocks
of fossil fuels
• predictable source
of energy
Mark
(6)
Level
1
0
1-2
2
3-4
3
5-6
• regular/reliable
supply of energy
• barrages at
different areas would
give energy supply
at different times
Disadvantages of
tidal power• does
not give continuous
supply of energy
• destruction of
plant/animal/bird
habitats • problems
with passage of
ships • affects
migration of fish
• high capital cost
/very long payback
time • pollution
caused from
producing
/transporting building
materials • visual
pollution This list is
not exhaustive. Give
credit for other
plausible
suggestions
No rewardable material
• there is limited discussion of the
advantages or disadvantages of tidal power
ie gives one advantage OR one
disadvantage of tidal power. e.g. tidal power
is not available 24 hours a day/ The barrage
will save fuel for motorists going to the town
on the other side ( of the estuary) • the
answer communicates ideas using simple
language and uses limited scientific
terminology • spelling, punctuation and
grammar are used with limited accuracy
• there is some discussion of the
advantages and disadvantages of tidal
power ie gives one advantage AND one
disadvantage of tidal power e.g. an
advantage of tidal power is that it uses a
renewable energy resource and a
disadvantage is that they damage birds’
habitats • the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately • spelling, punctuation and
grammar are used with some accuracy
• there is detailed discussion of the
advantages and disadvantages of tidal
power ie gives one advantage AND one
disadvantage of tidal power, one of which is
detailed, AND a clear link to another method
e.g. tidal power stations are a good idea
because they use a renewable energy
resource and will help to conserve fossil fuel
stocks. However, it causes problems for
migrating fish • the answer communicates
ideas clearly and coherently uses a range of
scientific terminology accurately • spelling,
punctuation and grammar are used with few
errors
Q2.
Indicative Content
Mark
(6)
QWC
*
A discussion
including some of
the following points
Level
1
0
1-2
No rewardable content
 A limited description of one advantage or
one disadvantage
e.g. energy saving lamps last a long time/
filament lamps get very hot
OR
A correct value quoted from information with
no comparison.
 The answer communicates ideas using
simple language and uses limited scientific
terminology
 Spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 A simple description of two different
advantages / disadvantages
e.g. energy saving lamps cost more but last
longer / filament lamps have a short life time
and use more power
OR
Correct values quoted from table and used
to provide two comparisons without
calculations
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 A detailed description of two different
advantages / disadvantages using a
quantitative comparison.
e.g. energy saving lamps cost 5 times more
but last 10 times longer. / Energy saving
lamps produce 4 times as much light energy
for every 100J of electrical energy supplied
and are much more efficient. / Energy saving
lamps last 9,000 hours longer than and they
use less power.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Q3.
Indicative Content
QWC
Level
1
*
0
1-2
Mark
A discussion
including some of
the following points
 improved lighting
levels for LEDs
 energy savings
per year for LEDs or
calculation of
payback time
 calculation of
energy savings over
lifetime of LEDs or
calculation of
monetary savings by
using LEDs per year
 link to savings in
fossil fuels for LEDs
or link to reduced
CO2 produced for
LEDs and reduced
global warming
 comparison of
lifetimes and
(6)
maintenance cost
No rewardable content
 a limited discussion of benefits using
some pieces of the information provided,
e.g. LEDs last 40 000 hours longer and the
lighting levels are 200% brighter.
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple discussion of benefits using
some pieces of the information and
processing one of them OR 2 processed
pieces of information. e.g. LEDs save 3000
kW h of energy each year and are much
brighter. The money they save each year
compared to fluorescents is £420. OR The
payback time for the LEDs is about 5 years
and in that time they would have to pay for
the fluorescent lights to be replaced 5 times.
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed discussion of benefits using
processed information covering more than
half of the data points in the table e.g. LEDs
use less energy each year and this means
that fossil fuel reserves are not used up as
quickly. The LEDs save £420 each year and
have a payback time of about 5 years.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Q4.
Q5.
Q6.
Question
Number
(a)
Answer
Acceptable answers
Mark
alternating current
can take positive and
negative values RA
(1)
Question
Number
(b)(i)
Answer
a.c. above and
below zero /the line
a.c. goes one way
and then the other
RA
Acceptable answers
(1)
Mark
substitution: (1)
Allow substitution
and transposition in
either order if clear
transposition: (1)
Question
Number
(b)(ii)
Question
Number
QWC
evaluation /
comment: (1) 825(V)
/ which is about 800
(V)
Answer
• power input =
power output (1) • I
= 0.033 (A) (1)
*(c)
Correct comparison
of ratios scores 3 (15
and 14.5, 0.067 and
0.069)
Acceptable answers
(3)
Mark
power input = 55 x
0.5 (W) power input
= 27.5 (W) I = 0.034
(A) Give full marks
for correct answer no
working
Indicative Content
(2)
Mark
An explanation
linking some of the
following points
Basic ideas•
• transmission lines
have resistance
• the current warms
the transmission
wires • energy is
wasted as heat
• transformers
change voltage
and/or current • R
increase the voltage
/ RA for S • R
decrease the current
/ RA for S Linked
ideas• the long
transmission lines
have high resistance
• power depends on
both current and
voltage • power =
current × voltage (P
= I × V) • at high
voltage, the same
(6)
power needs less
Level
1
0
1-2
2
3-4
3
5-6
current • correct
mention of turns ratio
related to voltage
change • a smaller
current in a wire
produces less heat
• high voltage
transmission saves
more energy than is
lost in the
transformers
No rewardable material
• a limited explanation including some
relevant details e.g. R steps up the voltage,
S steps it down • the answer communicates
ideas using simple language and uses
limited scientific terminology • spelling,
punctuation and grammar are used with
limited accuracy
• a simple explanation relating operation of
transformers to heat loss in transmission
lines and/or transformers e.g. R steps up the
voltage so that less heat is lost in
transmission lines or high voltage
transmission saves more energy than is lost
in the transformers • the answer
communicates ideas showing some
evidence of clarity and organisation and
uses scientific terminology appropriately
• spelling, punctuation and grammar are
used with some accuracy
• a detailed explanation relating operation
of transformers to current and energy losses
in transmission lines and/or transformers
e.g. R steps up the voltage so that, for the
same power, I is less meaning less heat is
lost in transmission lines • the answer
communicates ideas clearly and coherently
uses a range of scientific terminology
accurately • spelling, punctuation and
grammar are used with few errors
Q7.
Answer
(ai)
(aii)
(aiii)
(aiv)
QWC
Model A because
Model A (can
produce up to
)7200kWh per year
(at 13mph) / will
produce 6000 kWh
(with given wind
speed). (1)
Substitution (1)
0.14 × 6000
Evaluation (1)
(£)840
Acceptable
answers
Model B produces
less than 6000kWh
per year at 13mph
/requires wind speed
of more than 13mph
to produce 6000kWh
Allow incorrect
conversion of p to £
such as 0.014 ×
6000 for 1 mark only
84 000 p correct
answer with no
working shown gains
both marks
Divide the installation £840 for annual
cost by the annual
saving
saving (to find the
time in years)
(1)
A suggestion linking
not get hot /
(energy saving
produce so much
lamps) would not
heat
transfer so much
reverse argument
thermal energy (1)
such as insufficient
he may have to use
heat for chicks to
additional heating /
thrive (Ignore
lights (which would
references to light
cost money to run/
output.)
purchase) (1)
*(b)
Mark
(1)
(2)
(1)
(2)
Indicative Content
Mark
A discussion
including some of
the following points
 Both HEP and
Solar power are
renewable
 Both HEP and
Solar power would
save fossil fuels
 HEP only
possible in some
locations
 HEP requires
reservoirs and
damming of rivers
 This can
damage environment
/takes a lot of land
out of use
 Energy from
(6)
Level
1
0
1-2
solar power
installation is
currently much less
than energy from
fossil fuel powered
station
 Solar power only
suitable in certain
locations
 Solar power
reliability dependent
on constant
sunshine
 Neither of them
cause atmospheric
pollution
No rewardable content
 a limited description such as at least
one relevant detail of each resource eg:
Solar power doesn't give off atmospheric
pollution. HEP generates more power than
solar power.
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple discussion such as one which
gives comparisons between the two or at
least an advantage and disadvantage of
both. eg: HEP does not use fossil fuels but it
can damage the environment where is it
located. Solar power will never run out but it
requires lots of light/land.
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed comparison such as one
which relates advantages and
disadvantages of both HEP and solar power
to a particular situation for possible large
scale use e.g.: Solar power uses a
renewable energy source but it currently
does not produce as much energy as fossil
fuel station where there is little sunlight. HEP
can produce a lot more energy where there
are hills and water but only possible in
certain geographical locations.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Q8.
Question
Number
(a)
Question
Number
(b)(i)
Question
Number
(b)(ii)
Question
Number
QWC
Answer
B
Answer
Acceptable answers
Mark
Acceptable answers
(1)
Mark
an explanation
linking three of the
following • (waves
cause) float to move
(up and down)(1)
• (this causes)
magnet to move (in
and out of coil) (1)
• (hence) magnetic
field (of magnet) (1)
• cuts across/links/
interacts wire in coil
(1)
• inducing/generatin
g potential difference
across ends of coil
(1)
Answer
magnet moves (in
the coil)
Allowcurrent/voltage
/volts/am ps
induced/generated in
coil
a description
including two of the
following • increase
the number of turns
on the coil (1) • use
a more powerful
magnet (1) • use full
scale device (1)
more coils (of wire)
ignore bigger coil
stronger/more
magnets Ignore
bigger magnet Allow
idea of more/bigger/
faster waves
*(c)
Acceptable answers
(3)
Mark
Indicative Content
(2)
Mark
A discussion linking
some of the following
Advantages of tidal
power• renewable
energy source
• reduction in
greenhouse
gases/atmospheric
pollution (compared
to fossil fuel)
• reduces reliance
on fossil fuels
• conserves stocks
of fossil fuels
• predictable source
of energy
• regular/reliable
supply of energy
• barrages at
different areas would
give energy supply
at different times
(6)
Level
1
0
1-2
2
3-4
3
5-6
Disadvantages of
tidal power• does
not give continuous
supply of energy
• destruction of
plant/animal/bird
habitats • problems
with passage of
ships • affects
migration of fish
• high capital cost
/very long payback
time • pollution
caused from
producing
/transporting building
materials • visual
pollution This list is
not exhaustive. Give
credit for other
plausible
suggestions
No rewardable material
• there is limited discussion of the
advantages or disadvantages of tidal power
ie gives one advantage OR one
disadvantage of tidal power. e.g. tidal power
is not available 24 hours a day/ The barrage
will save fuel for motorists going to the town
on the other side ( of the estuary) • the
answer communicates ideas using simple
language and uses limited scientific
terminology • spelling, punctuation and
grammar are used with limited accuracy
• there is some discussion of the
advantages and disadvantages of tidal
power ie gives one advantage AND one
disadvantage of tidal power e.g. an
advantage of tidal power is that it uses a
renewable energy resource and a
disadvantage is that they damage birds’
habitats • the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately • spelling, punctuation and
grammar are used with some accuracy
• there is detailed discussion of the
advantages and disadvantages of tidal
power ie gives one advantage AND one
disadvantage of tidal power, one of which is
detailed, AND a clear link to another method
e.g. tidal power stations are a good idea
because they use a renewable energy
resource and will help to conserve fossil fuel
stocks. However, it causes problems for
migrating fish • the answer communicates
ideas clearly and coherently uses a range of
scientific terminology accurately • spelling,
punctuation and grammar are used with few
errors
Q9.
Answer
(a)(i)
(a)(ii)
(b)(i)
(b)(ii)
D
ampere(s), amp(s), A
A description linking
magnet (1)
(in/near) coil (1)
(magnet/coil)
spins/moves/turns
(1)
Any one from the
following: Increase
strength of magnet
(1) Increase number
of coils/turns of wire
(1) Increase speed
of rotation (1)
*(c)
Acceptable
answers
Mark
(1)
(1)
IGNORE handle
turns
add another
magnet / move
magnets closer
turn
handle/magnet/coil
faster IGNORE
bigger magnet/coil/
generator / longer
wire
Indicative Content
A comparison
including some of
the following points
Non- renewable
sources
 coal, oil, gas and
nuclear
 coal, oil, gas are
fossil fuels
 fossil fuels will
run out
 fossil fuels burn
and produce CO2
 fossil fuels burn
to produce
atmospheric pollution
 CO2 contributes
to global warming
 are a more
expensive source
 Nuclear power
stations do not
produce CO2
 Nuclear power
produces radioactive
waste
 Radioactive
waste is dangerous
and difficult to store
safelyRenewable
resources
 Wind, waves,
solar, biofuels,
geothermal and
hydroelectric
(3)
(1)
Mark
(6)
Level
1
0
1-2
 are a
free/cheaper source
 The energy
source is unreliable
 No (net) CO2
produced
 No atmospheric
pollution (except
biofuels)
 Waves and
hydroelectric cause
environmental
changes
 Wind farms and
solar panels give
visual pollution
 Wind farms can
be built off shore
Comparison
 Fossil fuel power
stations are cheaper
to build than wind
farms for the same
power output
 Coal, oil, gas and
nuclear fuel will run
out, wind, waves and
sun will always be
available
 Fossil fuel power
stations produce
CO2 which may
increase global
warming, renewable
energy generators
(wind farms) do not
 Renewable
energy generators
have a free/cheaper
source of fuel
 fossil fuels have
to be taken out of the
ground
 Nuclear power
stations produce
radioactive waste,
which is dangerous,
none of the other
energy generators
do this.
 Wind, waves and
sun are unreliable
sources of energy
but fossil and
nuclear fuels are
always available
No rewardable content
 a limited statement about either
renewable or non-renewable e.g. Coal is
non-renewable OR renewable energy will
not run out OR oil will run out
 the answer communicates ideas using
simple language and uses limited scientific
terminology.
 spelling, punctuation and grammar are
used with limited accuracy.
2
3-4
 a simple comparison including 2
statements covering renewable and nonrenewable e.g. Coal is non-renewable and
solar power is renewable OR renewable
energy sources will not run out and
nonrenewable sources do not pollute the
atmosphere OR oil will run out, solar will not
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately.
 spelling, punctuation and grammar are
used with some accuracy.
3
5-6
 a detailed comparison including at least
3 statements with a direct comparison
between a renewable and a non-renewable
source, at least one named e.g. Renewables
will not run out but nonrenewables like coal
will. OR Coal is non-renewable. When it is
burnt carbon dioxide is produced. Wind
farms do not produce any carbon dioxide.
OR Carbon dioxide is produced when coal is
used. Wind farms do not produce any
carbon dioxide. Wind farms are noisy. OR
Oil will run out, solar will not. Oil causes air
pollution
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately.
 spelling, punctuation and grammar are
used with few errors.
Q10.
Q11.
Indicative Content
Mark
A discussion
including some of
the following points
 Both HEP and
Solar power are
renewable
 Both HEP and
Solar power would
save fossil fuels
 HEP only
possible in some
locations
 HEP requires
reservoirs and
damming of rivers
 This can
damage environment
/takes a lot of land
out of use
 Energy from
solar power
installation is
currently much less
than energy from
fossil fuel powered
station
 Solar power only
suitable in certain
locations
 Solar power
(6)
Level
1
0
1-2
reliability dependent
on constant
sunshine
 Neither of them
cause atmospheric
pollution
No rewardable content
 a limited description such as at least
one relevant detail of each resource eg:
Solar power doesn't give off atmospheric
pollution. HEP generates more power than
solar power.
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple discussion such as one which
gives comparisons between the two or at
least an advantage and disadvantage of
both. eg: HEP does not use fossil fuels but it
can damage the environment where is it
located. Solar power will never run out but it
requires lots of light/land.
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed comparison such as one
which relates advantages and
disadvantages of both HEP and solar power
to a particular situation for possible large
scale use e.g.: Solar power uses a
renewable energy source but it currently
does not produce as much energy as fossil
fuel station where there is little sunlight. HEP
can produce a lot more energy where there
are hills and water but only possible in
certain geographical locations.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Q12.
Indicative Content
Level
1
0
1-2
Mark
A comparison
including some of
the following ideas
 Transformers
can be used or
voltages/currents
can be
changed/transforme
d
 AC (can
transmit) at lower
current/high(er)
voltage
 National Grid is
(usually) over ground
(DC cables (were)
underground)
 Less energy lost
(6)
in transmission
Exp
 National Grid
system can supply to
customers further
away
 Possible to
create a grid linking
power stations
 More flexibility in
voltage for consumer
 Consumer can
draw large(r) current
 More flexibility in
power drawn
 Great(er) range
of devices can be
powered Ignore
methods of electricity
production
No rewardable content
 a limited (maybe implied) comparison
giving one fact e.g: AC can be at high(er)
voltage OR the National Grid can supply
houses not close to a power station/ further
(away/than the New York system.)
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple comparison including two ideas
which may be linked or not eg Nat. Grid can
supply whole country and can be used for
more appliances (than just lighting). e.g: AC
can be transmitted further (than DC)
(because it) wastes less energy
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 A detailed comparison including at least
three ideas, with at least one direct link
between two of them.
 e.g. AC can be transmitted further (than
DC) because AC can be transformed to
lower current/high(er) voltages.
OR
AC can be transformed to lower
current/high(er) voltages.
Greater range of devices used.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Q13.
Answer
(ai)
Substitution (1)
1.5 × 6
Evaluation (1)
9 (W) Ignore any
unit given by
candidate.
(aii)
 More turns on
the coil (1)
 More
powerful/stronger
magnet(s) (1)
(aiii)
QWC
A description
including
 in one direction
only for DC (1)
 reversing
direction for AC (1)
*(b)
Acceptable
answers
Power of 10 error
max 1 mark Give full
marks for correct
answer with no
working shown
Wrap coils on iron
(core/former)/ more
coils/twists/loops.
Bigger coil is
insufficient. More
magnets.
Bigger/larger magnet
is insufficient. Ignore
increase speed of
rotation
'DC goes straight' is
insufficient AC
switches/changes
direction OR moves
to and fro 'AC goes
different ways' is
insufficient. Diagram
with labelled arrows
could get 2 marks.
Mark
(2)
(2)
(2)
Indicative Content
Mark
A comparison
including some of
the following ideas
 Transformers
can be used or
voltages/currents
can be
changed/transforme
d
 AC (can
transmit) at lower
current/high(er)
voltage
 National Grid is
(usually) over ground
(DC cables (were)
underground)
 Less energy lost
in transmission
 National Grid
system can supply to
customers further
away
 Possible to
create a grid linking
power stations
(6)
Exp
Level
1
0
1-2
 More flexibility in
voltage for consumer
 Consumer can
draw large(r) current
 More flexibility in
power drawn
 Great(er) range
of devices can be
powered Ignore
methods of electricity
production
No rewardable content
 a limited (maybe implied) comparison
giving one fact e.g: AC can be at high(er)
voltage OR the National Grid can supply
houses not close to a power station/ further
(away/than the New York system.)
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple comparison including two ideas
which may be linked or not eg Nat. Grid can
supply whole country and can be used for
more appliances (than just lighting). e.g: AC
can be transmitted further (than DC)
(because it) wastes less energy
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 A detailed comparison including at least
three ideas, with at least one direct link
between two of them.
 e.g. AC can be transmitted further (than
DC) because AC can be transformed to
lower current/high(er) voltages.
OR
AC can be transformed to lower
current/high(er) voltages.
Greater range of devices used.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Total for Question = 12 mark
Q14.
Indicative Content
*
A comparison
including some of
the following points
Non- renewable
sources
 coal, oil, gas and
nuclear
 coal, oil, gas are
fossil fuels
 fossil fuels will
run out
 fossil fuels burn
and produce CO2
 fossil fuels burn
to produce
atmospheric pollution
 CO2 contributes
to global warming
 are a more
expensive source
 Nuclear power
stations do not
produce CO2
 Nuclear power
produces radioactive
waste
 Radioactive
waste is dangerous
and difficult to store
safelyRenewable
resources
 Wind, waves,
solar, biofuels,
geothermal and
hydroelectric
 are a
free/cheaper source
 The energy
source is unreliable
 No (net) CO2
produced
 No atmospheric
pollution (except
biofuels)
 Waves and
hydroelectric cause
environmental
changes
 Wind farms and
solar panels give
visual pollution
 Wind farms can
be built off shore
Comparison
Mark
(6)
Level
1
0
1-2
 Fossil fuel power
stations are cheaper
to build than wind
farms for the same
power output
 Coal, oil, gas and
nuclear fuel will run
out, wind, waves and
sun will always be
available
 Fossil fuel power
stations produce
CO2 which may
increase global
warming, renewable
energy generators
(wind farms) do not
 Renewable
energy generators
have a free/cheaper
source of fuel
 fossil fuels have
to be taken out of the
ground
 Nuclear power
stations produce
radioactive waste,
which is dangerous,
none of the other
energy generators
do this.
 Wind, waves and
sun are unreliable
sources of energy
but fossil and
nuclear fuels are
always available
No rewardable content
 a limited statement about either
renewable or non-renewable e.g. Coal is
non-renewable OR renewable energy will
not run out OR oil will run out
 the answer communicates ideas using
simple language and uses limited scientific
terminology.
 spelling, punctuation and grammar are
used with limited accuracy.
2
3-4
 a simple comparison including 2
statements covering renewable and nonrenewable e.g. Coal is non-renewable and
solar power is renewable OR renewable
energy sources will not run out and
nonrenewable sources do not pollute the
atmosphere OR oil will run out, solar will not
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately.
 spelling, punctuation and grammar are
used with some accuracy.
3
5-6
 a detailed comparison including at least
3 statements with a direct comparison
between a renewable and a non-renewable
source, at least one named e.g. Renewables
will not run out but nonrenewables like coal
will. OR Coal is non-renewable. When it is
burnt carbon dioxide is produced. Wind
farms do not produce any carbon dioxide.
OR Carbon dioxide is produced when coal is
used. Wind farms do not produce any
carbon dioxide. Wind farms are noisy. OR
Oil will run out, solar will not. Oil causes air
pollution
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately.
 spelling, punctuation and grammar are
used with few errors.
Q15.
Question
Number
QWC
Indicative Content
*
Level
1
0
1-2
2
3-4
Mark
An explanation
linking some of the
following points
Basic ideas•
• transmission lines
have resistance
• the current warms
the transmission
wires • energy is
wasted as heat
• transformers
change voltage
and/or current • R
increase the voltage
/ RA for S • R
decrease the current
/ RA for S Linked
ideas• the long
transmission lines
have high resistance
• power depends on
both current and
voltage • power =
current × voltage (P
= I × V) • at high
voltage, the same
power needs less
current • correct
mention of turns ratio
related to voltage
change • a smaller
current in a wire
produces less heat
• high voltage
transmission saves
more energy than is
lost in the
(6)
transformers
No rewardable material
• a limited explanation including some
relevant details e.g. R steps up the voltage,
S steps it down • the answer communicates
ideas using simple language and uses
limited scientific terminology • spelling,
punctuation and grammar are used with
limited accuracy
• a simple explanation relating operation of
transformers to heat loss in transmission
lines and/or transformers e.g. R steps up the
voltage so that less heat is lost in
transmission lines or high voltage
transmission saves more energy than is lost
in the transformers • the answer
communicates ideas showing some
evidence of clarity and organisation and
3
5-6
uses scientific terminology appropriately
• spelling, punctuation and grammar are
used with some accuracy
• a detailed explanation relating operation
of transformers to current and energy losses
in transmission lines and/or transformers
e.g. R steps up the voltage so that, for the
same power, I is less meaning less heat is
lost in transmission lines • the answer
communicates ideas clearly and coherently
uses a range of scientific terminology
accurately • spelling, punctuation and
grammar are used with few errors
Q16.
Question
Number
(i)
Answer
Acceptable answers
Acceptdeither
order for
transformation /
substitution give 2
marks for correct
answer, no working
evaluation (1) 27
Question
Number
QWC
Mark
Indicative content
* (ii)
(3)
Mark
Basic
ideas• transforme
rs change voltage
and/or current
• transformers
use a.c. • the
current warms the
transmission wires
• step-up
transformers
increase the
voltage • step-up
transformers
decrease the
current • energy is
wasted
Linked• power
depends on both
current and voltage
• power = current
× voltage (P = I ×
V) • at high
voltage, the same
power needs less
current • correct
mention of turns
ratio related to
voltage change
• a smaller current
in a wire produces
less heat
Including
reasons• when
you use a higher
voltage, the current
is lower. With lower
current, the
amount of heat
produced is less. If
less heat is lost,
the efficiency is
(6)
Q17.
Level
1
0
1-2
2
3-4
3
5-6
greater. • correct
use of (P = I × V)
to show that
current is less in
the transmission
wires. Less heat is
lost because the
current is lower. If
less heat is lost,
the efficiency is
greater. • current
wastes heat in
wires. Using a
higher transmision
voltage, and
therefore a lower
current, saves
more energy in the
transmission wire
than is lost in the
transformers
no rewardable material
• basic relevant ideas, not linked and no
explanation or reason • e.g. the current
warms the transmission wires • the
answer communicates ideas using
simple language and uses limited
scientific terminology • spelling,
punctuation and grammar are used with
limited accuracy
• detailed comments linking ideas
• e.g. a smaller current in a wire
produces less heat • the answer
communicates ideas showing some
evidence of clarity and organisation and
uses scientific terminology appropriately
• spelling, punctuation and grammar
are used with some accuracy
• full explanation with reasons • e.g.
transformers are used to reduce the
current so that the heat loss is less and
efficiency is more • the answer
communicates ideas clearly and
coherently uses a range of scientific
terminology accurately • spelling,
punctuation and grammar are used with
few errors
Q18.
Answer
(a)
(b)
B charge
Substitution
12 × 230
(1)
evaluation
2800 (W)
(c)
(1)
Conversion
0.4 (kW)
(1)
Substitution
0.4 × 10 ×15 (p)
(1)
or
0.4 × 10 × 0.15 (£)
Evaluation
60(p) or £0.6
(1)
QWC
*(d)
Level
1
0
1-2
Acceptable
answers
2760 (W)
give full marks for
correct
answer, no
working Power of
10 error max. 1
mark.
give marks
for correct answer,
no working
60(p) or £0.6
Mark
(1)
(2)
(3)
(3)
60,000(p) or £600
(
2)
6 to any other
power of 10
(1)
(400/40/4) × 10 ×
(15/0.15) gains one
mark if no mark
can be awarded for
evaluation.
Indicative
Content
A discussion
including some of
the following points
Mark
(6)
No rewardable content
 A limited description of one
advantage or one disadvantage
e.g. energy saving lamps last a long
time/ filament lamps get very hot
OR
A correct value quoted from information
with no comparison.
 The answer communicates ideas
using simple language and uses limited
scientific terminology
 Spelling, punctuation and grammar
are used with limited accuracy
2
3-4
 A simple description of two different
advantages / disadvantages
e.g. energy saving lamps cost more but
last longer / filament lamps have a short
life time and use more power
OR
Correct values quoted from table and
used to provide two comparisons without
calculations
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific
terminology appropriately
 spelling, punctuation and grammar
are used with some accuracy
3
5-6
 A detailed description of two different
advantages / disadvantages using a
quantitative comparison.
e.g. energy saving lamps cost 5 times
more but last 10 times longer. / Energy
saving lamps produce 4 times as much
light energy for every 100J of electrical
energy supplied and are much more
efficient. / Energy saving lamps last
9,000 hours longer than and they use
less power.
 the answer communicates ideas
clearly and coherently uses a range of
scientific terminology accurately
 spelling, punctuation and grammar
are used with few errors
Q19.
Answer
(a)
(b)
(c)
QWC
transformer
A suggestion to
include any 2 of
the following
 (LED) turns on
and off
 as
voltage/current
changes
direction/from +ve
to –ve/ twice each
second (1)
 (LED) on for
(+ve ) part of cycle
(1)
 (LED) off for (ve) part of cycle (1)
substitute (1)
3 = I × 12
transformation (1)
I = 3 ÷ 12
evaluation (1)
0 .25 (A) Ignore
any unit given by
candidate
*(d)
Acceptable
answers
Step-up
transformer Stepdown transformer
Flash(es) /
flicker(s) (on and
off) current
changes every
0.25 s /4 times
each second
Turns on twice
each second = 2
marks Only on
when
voltage/current is
+ve gains both
marks
Mark
(1)
(2)
Subst. and
transform. either
order
1 mark only can
be scored for
correct substitution
after incorrect
transposition.
Accept any number
of sig. figs. that
rounds to 0.25 (A)
250 mA gains 3
marks give full
marks for correct
answer, no working
2.5 × any other
power of ten = 2
marks eg 25 (A)
gains 2 marks
(3)
Indicative
Content
A discussion
including some of
the following points
 improved
lighting levels for
LEDs
 energy savings
per year for LEDs
Mark
(6)
Level
1
0
1-2
or calculation of
payback time
 calculation of
energy savings
over lifetime of
LEDs or calculation
of monetary
savings by using
LEDs per year
 link to savings
in fossil fuels for
LEDs or link to
reduced CO2
produced for LEDs
and reduced global
warming
 comparison of
lifetimes and
maintenance cost
No rewardable content
 a limited discussion of benefits using
some pieces of the information provided,
e.g. LEDs last 40 000 hours longer and
the lighting levels are 200% brighter.
 the answer communicates ideas
using simple language and uses limited
scientific terminology
 spelling, punctuation and grammar
are used with limited accuracy
2
3-4
 a simple discussion of benefits using
some pieces of the information and
processing one of them OR 2 processed
pieces of information. e.g. LEDs save
3000 kW h of energy each year and are
much brighter. The money they save
each year compared to fluorescents is
£420. OR The payback time for the
LEDs is about 5 years and in that time
they would have to pay for the
fluorescent lights to be replaced 5 times.
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific
terminology appropriately
 spelling, punctuation and grammar
are used with some accuracy
3
5-6
 a detailed discussion of benefits
using processed information covering
more than half of the data points in the
table e.g. LEDs use less energy each
year and this means that fossil fuel
reserves are not used up as quickly. The
LEDs save £420 each year and have a
payback time of about 5 years.
 the answer communicates ideas
clearly and coherently uses a range of
scientific terminology accurately
 spelling, punctuation and grammar
are used with few errors
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