Q1.
The diagrams show what happens to each 100 joules of energy from burning coal on an
open fire and in a stove.
(a)
Add the missing figures to the diagrams.
(3)
(b)
Which is more efficient, the open fire or the stove?
Give a reason for your answer.
....................................................................................................................................
....................................................................................................................................
(1)
(Total 4 marks)
Page 1 of 52
Q2.
A car burns petrol as it travels along a flat road.
The diagram shows what happens to each 100 joules (J) of energy released by burning
the petrol.
Complete the diagram by adding the missing numbers.
(Total 3 marks)
Q3.
A gas burner is used to heat some water in a pan.
Of the energy released by the burning gas by the time the water starts to boil:
60% has been transferred to the water.
20% has been transferred to the surrounding air.
13% has been transferred to the pan.
7% has been transferred to the gas burner itself.
Page 2 of 52
(a)
Use the above information to complete the pie-chart.
(3)
(b)
Some of the energy released by the burning gas is wasted.
(i)
What happens to this wasted energy?
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
What percentage (%) of the energy from the gas is wasted? Answer: ................ %
(1)
(Total 6 marks)
Q4.
The diagram shows what happens to each 100 joules of energy from crude oil when it is
used as petrol in a car.
The widths of the arrows show exactly how much energy is transferred in each particular way.
(a)
Complete the diagram by adding the correct energy value alongside each arrow.
(3)
Page 3 of 52
(b)
Calculate how efficient the car engine is at transferring the energy from petrol into useful
movement.
[Show your working].
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Two students are discussing the diagram.
The first says that none of the energy released from the crude oil is really lost.
The other says that all of the energy released from the crude oil is really lost.
What do you think?
Explain your answer as fully as you can.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 9 marks)
Page 4 of 52
Q5.
The drawing shows parts of a house where it is possible to reduce the amount of energy
lost.
(a)
Give one way in which the amount of energy lost can be reduced from each of the
following parts of the house.
1, 2 and 4 ....................................................................................................................
5 ..................................................................................................................................
7 ..................................................................................................................................
(3)
(b)
Energy consumption can be reduced by using a more efficient boiler or more efficient light
bulbs.
What is meant by a more efficient light bulb?
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 4 marks)
Page 5 of 52
Q6.
Power stations are usually not very efficient. A lot of energy is wasted as thermal energy.
The diagrams show the percentage of energy transferred by two coal-burning power stations.
(a)
Write the two missing figures in the boxes on the diagrams.
(2)
(b)
Which power station is the most efficient overall, the normal power station or the
combined heat and power station? Give reasons for your answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
Page 6 of 52
(c)
Some heat energy released from burning coal on an open fire is emitted by radiation. Tick (
) the main type of electromagnetic radiation emitted by hot coal.
Type of
electromagnetic radiation
Tick
( )
gamma
infra red
ultraviolet
X-ray
(1)
(d)
Radiation can be reflected or absorbed when it strikes a surface. What type of surface is a
poor reflector but a good absorber of radiation?
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 6 marks)
Q7.
Complete the following sentences.
A TV set is designed to transfer electrical energy into .......................................................
energy and ......................................................... energy.
A hair dryer is designed to transfer electrical energy into ..................................................
energy and ................................................ energy.
(Total 4 marks)
Page 7 of 52
Q8.
The diagram below shows a 60 watt electric light bulb.
(a)
60 W means that 60 joules of energy are transferred into the bulb each second.
In use, how much energy is given out by the bulb each second?
.................................................................................................................................. J
(1)
(b)
Describe the energy transfers which occur as it is used.
................................... energy is transferred into ........................................... energy
and ................................................... energy.
(2)
(c)
Some of the energy given out is wasted. Why is some of the energy wasted?
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 4 marks)
Page 8 of 52
Q9.
A castle is a long way from the nearest town. Batteries power the car park ticket machine.
Solar cells are used to keep the batteries charged.
(a)
Complete the following sentences by choosing the correct words from the box.
Each word may be used once or not at all.
chemical
(i)
electrical
heat
light
sound
The energy input to the solar cells is ................................................ energy.
(1)
(ii)
The useful energy output from the solar cells is ........................................ energy.
(1)
(b)
For every 500 J of energy absorbed by the solar cells, 75 J of energy are transferred to the
batteries.
Use the following equation to calculate the efficiency of the solar cells. Show clearly how
you work out your answer.
Efficiency =
.....................................................................................................................................
.....................................................................................................................................
Efficiency = ……………………………
(2)
Page 9 of 52
(c)
Which one of the following statements gives the main reason for using solar cells to
charge the batteries?
Tick ( ) the box next to your choice.
Solar cells give a constant supply of electricity.
A few solar cells can provide a large amount of electricity.
The ticket machine is a long way from other electricity supplies.
(1)
(d)
The graph shows how the cost of producing electricity using solar cells has changed.
Use the graph to predict the cost of one Unit of electricity in 2010.
.....................................................................................................................................
(1)
(Total 6 marks)
##
(a)
In Britain most power stations burn fuel to produce heat. The diagram shows the stages
by which the heat is transferred into electrical energy.
Complete the diagram by filling in the missing word.
Water heated to
produce steam
→
Steam turns
a turbine
→
Turbine turns a
coil in a
→
Electricity is
produced
..........................
(1)
Page 10 of 52
(b)
A fuel burning power station uses 2000 joules of fuel energy to generate 600 joules of
electrical energy. The rest of the fuel energy is wasted as heat.
(i)
For every 600 joules of electrical energy generated, how much fuel energy is wasted
as heat?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Use the following equation to calculate the efficiency of the power station.
Show clearly how you work out your answer.
efficiency =
...........................................................................................................................
...........................................................................................................................
efficiency = ......................................................................
(2)
(c)
List A gives three energy resources used to generate electricity. List B gives
environmental problems that may be caused by using different energy resources. Draw a
straight line from each energy resource in List A to the environmental problem it may
cause in List B. Draw three lines only.
(3)
Page 11 of 52
(d)
A small wind generator is used to charge a battery. The graph shows the power output of
the generator at different wind speeds.
(i)
What is the maximum power produced by the generator?
................................................................................................................. watts
(1)
(ii)
The generator is designed to stop if the wind speed is too high.
At what wind speed does the generator stop working?
.................................................................................................................... m/s
(1)
(iii)
Give one disadvantage of using a wind generator to charge a battery.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 10 marks)
Page 12 of 52
Q11.
(a)
The drawing shows the energy transferred each second by a television set.
(i)
What form of energy is transferred as waste energy by the television set?
..........................................................................................................................
(1)
(ii)
What effect will the waste energy have on the air around the television set?
..........................................................................................................................
(1)
(iii)
Use the following equation to calculate the efficiency of the television set.
efficiency =
..........................................................................................................................
..........................................................................................................................
Efficiency = .............................................................
(2)
Page 13 of 52
(b)
The diagrams show the energy transferred each second for three different types of lamp.
For each lamp the electrical energy input each second is 100 joules.
Which type of lamp is the most efficient?
.....................................................................................................................................
Give a reason for your choice.
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
Page 14 of 52
##
(a)
The table gives information about some ways of reducing the energy consumption in a
house.
Method of reducing energy
consumption
Installation
cost in £
Annual saving on
energy bills in £
Fit a new hot water boiler
1800
200
Fit a solar water heater
2400
100
Fit underfloor heating
600
50
Fit thermostatic radiator valves
75
20
Which way of reducing energy consumption is most cost effective over a 10-year period?
To obtain full marks you must support your answer with calculations.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Explain why using an energy-efficient light bulb instead of an ordinary light bulb reduces the
amount of carbon dioxide emitted into the atmosphere.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 5 marks)
Page 15 of 52
Q13.
(a) The graph shows the temperature inside a flat between 5 pm and 9 pm. The central
heating was on at 5 pm.
(i)
What time did the central heating switch off?
...........................................................................................................................
(1)
(ii)
Closing the curtains reduces heat loss from the flat.
What time do you think the curtains were closed?
...........................................................................................................................
Give a reason for your answer.
...........................................................................................................................
(2)
Page 16 of 52
(b)
Less heat is lost through double-glazed windows than through single-glazed windows.
Complete the following sentences by choosing the correct words from the box. Each word
may be used once or not at all.
conduction
conductor
convection evaporation
insulator radiation
Air is a good ........................................... . When trapped between two sheets of glass it
reduces heat loss by .......................................... and ....................................................
(3)
(c)
The table gives information about three types of house insulation.
Cost to
install
Money save each
year on heating
bills
Payback time
Double glazing
£4000
£200
20 years
Loft insulation
£300
£100
3 years
Cavity wall insulation
£600
£150
Type of insulation
(i)
Use the information in the table to calculate the payback time for cavity wall
insulation.
...........................................................................................................................
(1)
Page 17 of 52
(ii)
Explain why people often install loft insulation before installing double glazing or cavity
wall insulation.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 9 marks)
Q14.
(a)
The picture shows a new washing machine.
Complete the following sentence using one of the words in the box.
kinetic
light
sound
A washing machine is designed to transform electrical energy into heat and
......................................................... energy
(1)
(b)
The instruction booklet for the washing machine contains the following information.
Wash cycle
Average power
during cycle
Time taken to
run cycle
HOT
1.5 kW
2 hours
COOL
1.1 kW
1½ hours
FAST
1.0 kW
¾ hour
Page 18 of 52
(i)
Use the following equation to calculate the energy transferred, in kilowatt-hours, to
the washing machine during the HOT wash cycle. Show how you work out your
answer.
energy transferred = power × time
...........................................................................................................................
...........................................................................................................................
Energy transferred = .................................... kWh
(2)
(ii)
Why does it cost more to use the washing machine on the HOT cycle than on the
COOL or FAST cycle?
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
Before buying a washing machine, a householder researched several makes to find
out which washing machine was the most energy efficient.
Write down one way that he could have done this research.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 5 marks)
Page 19 of 52
Q15.
(a) The diagram shows how much heat is lost each second from different parts of an
uninsulated house.
(i)
Each year, the house costs £760 to heat.
How much money is being wasted because of heat lost through the roof?
Show clearly how you work out your answer.
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
Insulating the loft would cut the heat lost through the roof by 50 %.
The loft insulation has a payback time of
years.
How much did the loft insulation cost to buy?
..........................................................................................................................
Cost of loft insulation = £ .................................................
(1)
(b)
What happens to the wasted energy?
....................................................................................................................................
....................................................................................................................................
(1)
(Total 4 marks)
Page 20 of 52
Q16.
The pictures show six different household appliances.
(a)
Four of the appliances, including the fan heater, are designed to transform electrical
energy into heat.
Name the other three appliances designed to transform electrical energy into heat.
1 .................................................................................................................................
2 .................................................................................................................................
3 .................................................................................................................................
(3)
(b)
Complete the following sentence using one of the words from the box.
chemical
heat
kinetic
sound
Energy that is not usefully transformed by the fan heater is wasted as
................................................. energy.
(1)
(c)
The table gives information about two different fan heaters.
Useful energy
transferred each
second in joules
Wasted energy
transferred each
second in joules
Fan heater L
1200
10
Fan heater M
1200
20
Complete the following sentence by drawing a ring around the line in the box that is
correct.
is more efficient than
Fan heater L
has the same efficiency as
fan heater M.
is less efficient than
(1)
(Total 5 marks)
Page 21 of 52
Q17.
(a)
In winter, energy is transferred from the warm air inside a house to the air outside.
(i)
What effect will the energy transferred from the house have on the air outside?
...........................................................................................................................
(1)
(ii)
What would happen to the energy transfer if the temperature inside the house were
reduced? Assume the temperature outside the house does not change.
...........................................................................................................................
(1)
(b)
To increase energy efficiency, a householder installs a heat exchanger to an outside wall
of the house. The heat exchanger uses heat from the air outside to warm the inside of the
house. The diagram shows the idea of the heat exchanger.
Physics Through Applications edited by J Jardine et el (OUP, 1989), copyright ©
Oxford University Press, reprinted by permission of Oxford University Press.
(i)
Why does the heat exchanger cost money to run?
...........................................................................................................................
(1)
(ii)
The heat exchanger is cost effective in reducing energy consumption.
Explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 5 marks)
Page 22 of 52
Q18.
The diagram shows the label from a new freezer.
(a)
An old freezer has an energy consumption per year of 350 kWh.
Use the equation in the box to calculate the extra cost of using the old freezer for one year
compared with using a new ‘A’ rated freezer.
total cost = number of kilowatt-hours × cost per kilowatt-hour
Assume 1 kilowatt-hour (kWh) of energy costs 12 p.
Show clearly how you work out your answer.
.....................................................................................................................................
.....................................................................................................................................
Extra cost per year = £ ..............................
(2)
(b)
The price of the new freezer was reduced in a sale.
Reducing the price reduces the payback time for replacing the old freezer from 12 years
to 9 years.
Calculate, in pounds, how much the new freezer was reduced in the sale.
Show clearly how you work out your answer.
.....................................................................................................................................
.....................................................................................................................................
Price reduced by = £ ........................................
(2)
Page 23 of 52
(c)
An advertisement in a shop claims that:
‘Replacing an old freezer with a new ‘A’ rated freezer will benefit the environment.’
Do you agree that replacing the freezer will benefit the environment?
Answer yes or no. ..............................
Explain the reasons for your answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks
Q19.
(a)
The diagram shows the energy transformations produced by a TV.
(i)
Use the information in the diagram and the equation in the box to calculate the
efficiency of the TV.
efficiency =
Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
Efficiency = ..............................
(2)
Page 24 of 52
(ii)
What eventually happens to the useful energy transferred by the TV?
...........................................................................................................................
...........................................................................................................................
(1)
(b)
Electrical appliances left on standby use energy.
The bar chart shows the power for the appliances that one family leaves on standby when
they go on holiday.
The family is on holiday for a total of 175 hours.
(i)
Use the information in the bar chart and the equation in the box to calculate the
energy wasted by leaving the compact stereo on standby while the family is on
holiday.
energy transferred
(kilowatt-hour, kWh)
=
power
(kilowatt, kW)
×
time
(hour, h)
Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
Energy wasted = .............................. kilowatt-hours
(2)
Page 25 of 52
(ii)
Electricity costs 12 p per kilowatt-hour.
Use the equation in the box to calculate the cost of leaving the compact stereo on
standby while the family is on holiday.
total cost = number of kilowatt-hours × cost per kilowatt-hour
Show clearly how you work out your answer.
...........................................................................................................................
Cost = .............................. p
(1)
(c)
A headline from a recent newspaper article is shown below.
Explain why leaving appliances on standby damages the environment.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 8 marks)
Q20.
The diagram shows the energy transformations produced by a TV.
(a)
Use words from the diagram to complete the following sentence.
The TV is designed to transform ............................................................ energy into
light and ................................................................... energy.
(2)
Page 26 of 52
(b)
Which one of the following statements is false?
Put a tick ( ) in the box next to the false statement.
The energy transformed by the TV makes the surroundings warmer.
The energy transformed by the TV becomes spread out.
The energy transformed by the TV will be destroyed.
(1)
(c)
Two different makes of television, A and B, transform energy at the same rate.
Television A wastes less energy than television B.
Complete the following sentence by drawing a ring around the correct line in the box.
a higher efficiency than
Television A has
the same efficiency as
television B.
a lower efficiency than
(1)
(Total 4 marks)
Q21.
The pictures show three different types of electric heater.
Page 27 of 52
(a)
The ceramic heater is run on full power for 5 hours.
Use the following equation to calculate, in kilowatt-hours, the amount of energy transferred
from the mains to the heater.
energy transferred = power × time
Show clearly how you work out your answer.
.....................................................................................................................................
.....................................................................................................................................
Energy transferred = .............................. kilowatt-hours
(2)
(b)
Which heater will be the most expensive to run on its highest heat setting?
.....................................................................................................................................
(1)
(c)
A heater is needed for a small office.
Comparing each type of heater with the other two, give one advantage of using each type
of heater in the office.
oil-filled panel heater .................................................................................................
.....................................................................................................................................
fan heater ....................................................................................................................
.....................................................................................................................................
ceramic heater .............................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Page 28 of 52
Q22.
A vacuum flask is designed to reduce the rate of heat transfer.
(a)
(i)
Complete the table to show which methods of heat transfer are reduced by each of
the features labelled in the diagram.
The first row has been done for you.
Feature
Conduction
Convection
Radiation
vacuum
silvered
surfaces
plastic cap
(2)
(ii)
Explain why the vacuum between the glass walls of the flask reduces heat transfer
by conduction and convection.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
The diagram shows a gas flame patio heater.
Page 29 of 52
(i)
Explain why the top surface of the reflecting hood should be a light, shiny surface
rather than a dark, matt surface.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Most of the chemical energy in the gas is transformed into heat. A small amount of
chemical energy is transformed into light.
Draw and label a Sankey diagram for the patio heater.
(2)
(iii)
State why the total energy supplied to the patio heater must always equal the total
energy transferred by the patio heater.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 9 marks)
Q23.
The picture shows a solar-powered aircraft. The aircraft has no pilot.
Photo by NASA.
Page 30 of 52
(a)
Use words from the box to complete the following sentence.
electrical
heat
light
sound
Solar cells are designed to transform .............................................................. energy into
.............................................................. energy.
(2)
(b)
On a summer day, 175 000 joules of energy are supplied to the aircraft’s solar cells every
second. The useful energy transferred by the solar cells is 35 000 joules every second.
(i)
Use the equation in the box to calculate the efficiency of the solar cells.
Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
Efficiency = ..............................................................
(2)
(ii)
What happens to the energy that is not usefully transferred by the solar cells?
...........................................................................................................................
(1)
(c)
The aircraft propellers are driven by electric motors. As well as the solar cells, there are
fuel cells that provide additional power to the electric motors.
(i)
Suggest one advantage of the aircraft having fuel cells as well as the solar cells.
...........................................................................................................................
(1)
(ii)
Give one environmental advantage of using electric motors to drive the aircraft
propellers rather than motors that burn a fuel.
...........................................................................................................................
...........................................................................................................................
(1)
Page 31 of 52
(iii)
Eventually, the designers want to produce an unmanned aircraft that can fly at twice
the height of a passenger jet for up to six months.
Suggest one possible use for an aircraft such as this.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 8 marks)
Q24.
The picture shows a food processor, which is used to grate, shred, liquidise and mix food.
The table gives some information about the food processor.
(a)
Energy input
Electrical
Useful energy
output
Kinetic
Power rating
1200 watts
Efficiency
0.8
The food processor is used for a total of 30 minutes a day.
Calculate the cost of the energy wasted by the food processor each day.
Electricity costs 15 p per kilowatt-hour.
Write down the equations you use, and then show clearly how you work out your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Cost of waste energy = ...................................... p
(4)
Page 32 of 52
(b)
Explain what happens to the waste energy.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 6 marks)
Q25.
(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)
Page 33 of 52
(b)
The diagram shows the energy transformations in a coal burning power station.
Calculate the efficiency of the power station.
Write down the equation you use, and then show clearly how you work out your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
Efficiency = ............................................
(2)
(c)
Draw a ring around the correct answer to complete the following sentence.
If fewer coal burning power stations are used to generate electricity the amount of
decrease.
carbon dioxide emitted into the atmosphere will
not change.
increase.
(1)
(d)
Some types of power station generate electricity by burning a biofuel.
Give one example of a biofuel.
........................................................................................................................
(1)
Page 34 of 52
(e)
Nuclear power stations generate electricity without burning a fuel.
Name the process by which a nuclear fuel provides the energy needed to generate
electricity.
........................................................................................................................
(1)
(Total 7 marks)
Page 35 of 52
M1.
(a)
(ii)
(i)
15*
60*
[* if incorrect but (ii)>(i) and (i) + (ii) = 75 then credit 1 mark]
(iii)
25
each for 1 mark
3
(b)
stove because
more of the energy heats up room / heats the room more
or
less energy escapes up chimney / less energy wasted
[Do not allow ‘less waste’ with the stove]
or
no un burnt fuel in smoke
reason for 1 mark
1
[4]
##
(a)
60
(b)
15
(c)
5
each for 1 mark
credit 1 mark for (a) +(b)+ (c) = 80
or (a) > (b) > (c) to maximum of 3
[3]
M3.
(a) 60% sector correct
other two sectors closer to 13:7 than 12:8 or 14:6
sectors correctly labelled (w.r.t rank order of size)
each for 1 mark
3
Page 36 of 52
(b)
(i)
ideas that wasted energy
is transferred to surrounding air
pan
stove
is converted to another/correctly named energy form
any 2 for 1 mark each
2
(ii)
40
for 1 mark
1
[6]
M4.
(a) ( B)
(
)
(A C)
A = B or A/B = 20
gains 1 mark
but A = B = 20
gains 2 marks
A + B + C = 100
for 1 further mark
or C = 60
3
(b)
evidence of
or 20%/0.2 gains 1 mark
but 25%/0.25 or figure consistent with B in part (a)
gains 2 marks
2
(c)
ideas that
“lost” energy is (also) transferred (in ways we don’t want)
total amount of energy (before and after any transfer) remains the same
energy becomes (progressively) more spread out/less easy to transfer again
this applies to all the energy/even to the energy usefully transferred
each for 1 mark
4
[9]
Page 37 of 52
M5.
(a)
insulation
allow example e.g fibreglass
1
double glazing
allow curtains
1
draught excluder
allow double glazing / close fitting door
allow turning down thermostat once only / turn down the heating
1
(b)
transfers more useful energy
allow converts more energy into light / less into heat / less energy
wasted
1
[4]
M6.
(a)
30(%)
1
50(%)
1
(b)
combined heat and power station as waste less energy
1
correct reference to 20 % or 70 %
accept some energy (50%) is used for heating
1
(c)
infra red ticked
1
(d)
dark surfaces
accept matt / dull / black surfaces
1
[6]
M7.
light;
sound;
heat;
kinetic/movement
for 1 mark each
[4]
Page 38 of 52
M8.
(a)
60
for 1 mark
1
(b)
electrical to light
gains 1 mark
but electricity to light and heat
gains 2 mark
anything to heat and light
gains 1 mark
2
(c)
(unwanted) heat produced
for 1 mark
1
[4]
M9.
(a)
light
1
electrical
1
(b)
15% or 0.15
correct substitution gains 1 mark only an answer of 15 with no unit
or an incorrect unit gains 1 mark an answer of 0.15 given with a
unit gains 1 mark
2
(c)
the ticket machine is a long way from other electricity supplies
1
(d)
any figure between 5 and 10 inclusive
unit not required but if given must match numerical answer
1
[6]
Page 39 of 52
M10.
(a)
generator
accept dynamo
accept alternator
1
(b)
(i)
1400
ignore units
1
(ii)
0.3 or 30%
any incorrect unit penalise 1 mark
allow 1 mark for the correct use of 600
or 0.3% or 30
2
(c)
1 mark for each correct link
if more than 3 lines are drawn, mark only
3 lines starting with those that are incorrect
3
(d)
(i)
110
no tolerance
1
(ii)
12
no tolerance
1
(iii)
wind speed may be too low to operate the generator
accept wind may not always blow
accept power depends on wind speed
accept does not generate if wind speed is too high
accept does not generate if wind speed is above 12 (m/s)
accept does not generate if wind speed is below 1.6 (m/s)
accept it is unreliable
do not accept answers referring to cost only
1
[10]
M11.
(a)
(i)
heat
1
(ii)
temperature increases or (cause) convection (currents)
accept gets warmer
accept gets hotter
1
Page 40 of 52
(iii)
60% or 0.6
60 without % scores 1 mark
0.6 with a unit scores 1 mark
60 with incorrect unit scores
1 mark
or correct substitution
for 1 mark
2
(b)
street
1
more (energy transferred as) light or less (energy transferred as) heat or useful
energy output the highest
can only score this mark if first mark scored
all efficiencies calculated correctly score 2nd mark point
1
[6]
M12.
(a)
four calculations correctly shown
200 × 10 – 1800 = £200
100 × 10 – 2400 = –£1400
50 × 10 – 600 = –£100
20 × 10 – 75 = 125
accept four final answers only or obvious rejection of solar water
heater and underfloor heating, with other two calculations
completed any 1 complete calculation correctly
shown or showing each saving × 10 of all four calculations = 1
mark answers in terms of savings as a percentage of installation
cost may score savings mark only
2
hot water boiler
correct answers only
1
(b)
less electricity / energy to be generated / needed from power stations
accept less demand
1
reduction in (fossil) fuels being burnt
accept correctly named fuel
accept answer in terms of:
fewer light bulbs required because they last longer (1 mark)
less energy used / fuels burnt in production / transport etc. (1
mark)
ignore reference to CO2 or global warming
ignore reference to conservation of energy
1
[5]
Page 41 of 52
M13.
(a)
(i)
7pm
accept 19.00 / 1900
1
(ii)
8pm
accept 20.00 / 2000
1
temperature drops more slowly
accept heat for temperature accept line is less steep
1
(b)
insulator
1
conduction *
1
convection *
* answers can be either way around
1
(c)
(i)
4 (years)
1
(ii)
it is the cheapest / cheaper / cheap
do not accept answers in terms of heat rising or DIY
1
has the shortest / shorter payback time
do not accept short payback time
1
[9]
M14.
(a)
kinetic
accept movement
1
Page 42 of 52
(b)
(i)
3 (kWh)
allow 1 mark for selecting the correct information
1
(ii)
transfers more energy
accept transform or use for transfer
accept electricity for energy
allow higher (average) power and switched on for more time
2
(iii)
any one from:
•
use the internet
•
brochures
•
reading adverts
•
visiting shops
•
recommendation from friends / plumbers
1
[5]
M15.
(a)
(i)
£190
nb mention idea of cost per J in £ will come to an approx figure full
credit given
allow 1 mark for showing that the energy loss through the roof is ¼
of the total energy loss ie 150 / 600
2
(ii)
£142.50
allow ecf 50 % of their (a)(i) × 1.5 ie their (a)(i) × 0.75
1
(b)
transferred to surroundings / atmosphere
or becomes spread out
1
[4]
M16.
(a)
iron
1
hairdryer
1
kettle
answers can be in any order
1
Page 43 of 52
(b)
sound
1
(c)
is more efficient than
1
[5]
M17.
(a)
(i)
makes it warmer / raises the temperature
accept produces convection (current)
accept makes it less dense
1
(ii)
reduced or slows down
1
(b)
(i)
electrical energy (to run the pump) must be paid for
accept electricity for electrical energy
accept electricity is needed for the pump
accept it uses electricity
accept because of the pump
1
(ii)
more useful (heat) energy is transferred into the house than the energy
used to operate the pump
or reduced cost of heating the house is greater than the cost of running the
(electrical) pump
or costs little to run compared to the savings made
accept for 1 mark
reduces energy bills
or reduced fuel costs / heating costs owtte
do not accept it’s cheap
2
[5]
M18.
(a)
£15
allow 1 mark for use of 125 (kWh)
allow 1 mark for an answer 1500
allow both marks for 1500 pence / p
allow 1 mark for correct calculation of annual cost for either freezer
(£27 and £42)
2
Page 44 of 52
(b)
£45
or their (a) × 3
allow 1 mark for correct use of 3
allow 1 mark for 12 – 9 = 3
2
(c)
any two from:
the marks are for the explanation
yes plus explanation
•
less electricity / energy needed / used
accept less energy wasted
•
less (fossil) fuels burned
accept a named fossil fuel
do not accept conserving (fossil) fuels
•
less polluting gases emitted
accept a named polluting gas / greenhouse gases / carbon
emissions / reduce global warming
accept an answer in terms of nuclear fuel
eg less nuclear fuel required (1)
less nuclear waste (1)
2
or no plus explanation
•
old freezer must be disposed of
•
hazardous chemicals inside freezer
accept CFC gases
•
(lot of) energy used in producing new freezer
[6]
M19.
(a)
(i)
0.6
accept 60 %
allow 1 mark for useful energy = 480
answer 0.6 with any unit or 60 gains 1 mark only
2
(ii)
transferred to surroundings
accept goes into the air
accept heats the surroundings up
accept gets spread out
accept transferred into heat (only)
do not accept wasted / lost unless qualified
destroyed negates mark
transferred into light / sound negates mark
1
Page 45 of 52
(b)
(i)
1.75
allow 1 mark for converting to kW
answers of 0.7, 0.525, 0.35, 0.875, 1.05, 5.25 gains 1 mark
answers of 1750 or 17.5 gains 1 mark
2
(ii)
21p or £0.21 or their (b)(i) × 12
1
(c)
any two from:
•
(more) electricity needs to be generated
(more) electricity is being used
•
(more) power stations needed
•
(more) fossil fuels burnt
accept named fossil fuel
•
(more) pollutant gases emitted
accept named gas
accept harmful for pollutant
accept greenhouse gases
accept atmospheric pollution
accept answer in terms of any form of electricity generation and an
associated environmental problem
2
[8]
M20.
(a)
electrical
1
sound
correct order only
1
(b)
the energy transformed by the TV will be destroyed
1
(c)
a higher efficiency than
1
[4]
M21.
(a)
9
allow 1 mark for correct substitution
(1.8 × 5)
an answer of 9000 gains 1 mark
an answer of 2 or 15 gains 1 mark
2
Page 46 of 52
(b)
(3kW) fan heater
accept 3kW
accept the middle one
1
(c)
features common to more than one heater, treat as neutral
oil-filled
low level heat
cannot be knocked over / space saving / no trailing wires
do not accept just wall-mounted
or more control over heat output
do not accept just 3 heat settings
1
fan
warms (office) rapidly or can be used to cool air (in summer)
accept can be used as a fan
accept cool air fan (setting)
accept ‘it has a cool air setting in case it gets too hot’
do not accept a specific reference to cooling the heater
1
ceramic
can be switched on for set periods of time
do not accept just has a timer
or can be switched on before office is used / switched off automatically at night
1
[6]
M22.
(a)
(i)
silvered surfaces
more than the correct number of ticks in a row negates the mark
radiation
2
plastic cap
conduction, convection (both required)
conduction
convection
radiation
vacuum
silvered surfaces
(1)
plastic cap
(1)
Page 47 of 52
(ii)
any mention of air or any other substance in a vacuum scores zero
because there are no particles in a vacuum
accept atoms / molecules for particles
accept vacuum is empty space
accept there is nothing in a vacuum
accept there is no air / gas in the vacuum
conduction and convection need particles / medium
need reference to both conduction and convection
accept correct descriptions
2
(b)
(i)
less heat lost (to air above the heater)
do not accept no heat lost
light shiny surfaces are poor emitters (of radiation)
accept radiators for emitters
references to reflection are neutral
or dull, matt surfaces are good emitters (of radiation)
do not credit answers which infer reflection from the underside of
the hood
ignore correct reference to absorption
2
(ii)
correct diagram drawn with one output arrow narrower
than the other
ignore input
arrows correctly labelled with energy form
eg
flow charts score zero
2
(iii)
energy cannot be destroyed
accept (principle of) conservation of energy
do not accept because energy cannot be lost without clarification
1
[9]
Page 48 of 52
M23.
(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
Page 49 of 52
(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]
M24.
(a)
1.8 (p)
these 4 marks can be broken down as follows:
1 mark for correct transformation and substitution into efficiency
equation
ie 0.8 × 1200 – useful power
PLUS
1 mark for useful power = 960 W / 0.96 kW
PLUS
1 mark for waste energy transferred = 0.24 × 0.5
or
waste energy transferred = 0.12 (kWh)
PLUS
1 mark for cost = 0.12 × 15
where a mathematical error has been made full credit should be
given for subsequent correct method
4
(b)
the waste energy is transferred as heat and sound
1
to the surroundings where it spreads out / is shared by
surrounding particles
accept air for surroundings
1
[6]
M25.
(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
Page 50 of 52
(e)
(nuclear) fission
1
[7]
Page 51 of 52
Page 52 of 52