1. business and industrial
2. energy
3. electricity

Energy transfers (Particle theory, conduction,
convection, IR, evaporation)
188 minutes
188 marks
Page 1 of 72
Q1.
(a) The diagrams, X, Y and Z, show how the particles are arranged in the three states of
matter.
(i)
Which one of the diagrams, X, Y or Z, shows the arrangement of particles in a
liquid?
Write the correct answer in the box.
(1)
(ii)
Which one of the diagrams, X, Y or Z, shows the arrangement of particles in a gas?
Write the correct answer in the box.
(1)
(b)
Draw a ring around the correct answer in each box to complete each sentence.
vibrating in fixed positions.
(i)
In a gas, the particles are
moving randomly.
not moving.
(1)
stronger than
(ii)
In a solid, the forces between the particles are
equal to
the forces between
weaker than
the particles in a liquid.
(1)
Page 2 of 72
(c)
The picture shows a puddle of water in a road, after a rain shower.
(i)
During the day, the puddle of water dries up and disappears. This happens because
the water particles move from the puddle into the air.
What process causes water particles to move from the puddle into the air?
Draw a ring around the correct answer.
condensation
evaporation
radiation
(1)
(ii)
Describe one change in the weather which would cause the puddle of water to dry
up faster.
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(1)
(Total 6 marks)
Page 3 of 72
Q2.
According to kinetic theory, all matter is made up of small particles. The particles are
constantly moving.
Diagram 1 shows how the particles may be arranged in a solid.
Diagram 1
(a)
One kilogram of a gas has a much larger volume than one kilogram of a solid.
Use kinetic theory to explain why.
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(4)
(b)
Diagram 2 shows the particles in a liquid. The liquid is evaporating.
Diagram 2
(i)
How can you tell from Diagram 2 that the liquid is evaporating?
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(1)
Page 4 of 72
(ii)
The temperature of the liquid in the container decreases as the liquid evaporates.
Use kinetic theory to explain why.
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(3)
(Total 8 marks)
Q3.
A student did two experiments on radiation. The apparatus he used is shown in the diagram.
Experiment 1
•
•
•
The student put the same volume of cold water into the two cans.
He then switched on the heater.
Ten minutes later the water in the can with the dull black surface was much hotter than the
water in the other can.
Page 5 of 72
Experiment 2
•
•
•
The student filled both cans with boiling water.
This time he left the heater off.
Ten minutes later the water in the can with the dull black surface was much cooler than
the water in the other can.
Use words from the box to complete the sentences.
absorber
conductor
emitter
reflector
Experiment 1 shows that the dull black surface is a good ........................... of radiation and that
the shiny silver surface is a good ......................... of radiation.
Experiment 2 shows that the dull black surface is a good ................................... of radiation.
(Total 3 marks)
Q4.
The diagrams show the cross-section of three double glazed windows.
The gap between the two sheets of glass can be filled with either air or a mixture of air and
argon.
The U-values for different types of double glazed windows, using different types of glass
X and Y, are given in the table.
Type of window
12 mm
gap
16 mm
gap
20 mm
gap
1
Glass type X with air
2.9
2.7
2.8
2
Glass type X with air and argon
2.7
2.6
2.6
3
Glass type Y with air
1.9
1.8
1.8
4
Glass type Y with air and argon
1.6
1.5
1.5
Page 6 of 72
(a)
Which type of window, 1, 2, 3 or 4 is the least energy efficient?
........................................................................................................................
(1)
(b)
Which two windows should be compared to decide if adding argon to the gap improves the
energy efficiency of the window?
........................................................................................................................
(1)
(c)
A householder is going to buy new windows. The sales assistant recommends that the
householder buys windows with a 20 mm gap. These windows are much more expensive
than those with a 16 mm gap.
It is not worth the householder paying the extra cost to buy 20 mm windows rather than
16 mm windows.
Explain this in terms of energy efficiency.
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(2)
(d)
Windows are given an energy rating, from A down to G. The diagram shows the energy
label from one type of double glazed window.
All new double glazed windows must have an energy rating of C or above.
Windows having a C rating have a U-value of 1.9.
Which windows given in the table would the householder be unable to buy?
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(1)
Page 7 of 72
(e)
Glass transmits infrared radiation and visible light. The amount transmitted depends on the
type and thickness of the glass. The data from tests on two different types of glass is
displayed in the graph below.
A homeowner has a glass conservatory built on the back of the house. The homeowner
tells the builder that the inside of the conservatory should stay as cool as possible
throughout the summer.
Explain why the builder uses ‘Type B’ glass for the conservatory.
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(2)
(Total 7 marks)
Page 8 of 72
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?
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(1)
(Total 4 marks)
Page 9 of 72
Q6.
The picture shows one type of solar water heater. Water from the tank is slowly pumped
through copper pipes inside the solar panel where the water is heated by energy from the Sun.
(a)
Explain why the copper pipes inside the solar panel are painted black.
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(2)
(b)
Each day the average European family uses 100 kg of hot water.
To kill bacteria, the water going into the tank at 20 °C must be heated to 60 °C.
Calculate the energy needed to increase the temperature of 100 kg of water by 40 °C.
Specific heat capacity of water = 4200 J/kg °C.
Write down the equation you use, and then show clearly how you work out your answer.
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Energy transferred = .................................... J
(2)
Page 10 of 72
(c)
The bar chart shows how the amount of solar energy transferred to the water heater varies
throughout the year.
How many months each year will there not be enough solar energy to provide the hot
water used by an average European family?
.................................................. months
(1)
Page 11 of 72
(d)
In this question you will be assessed on using good English, organising information clearly
and using specialist terms where appropriate.
The water in the tank could be heated by using an electric immersion heater.
Outline the advantages and disadvantages of using solar energy to heat the water rather
than using an electric immersion heater.
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(6)
(Total 11 marks)
Q7.
The drawing shows water being heated in a metal saucepan.
(a)
Explain, in terms of the particles in the metal, how heat energy is transferred through the
base of the saucepan.
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(2)
Page 12 of 72
(b)
Energy is transferred through the water by convection currents. Explain what happens to
cause a convection current in the water. The answer has been started for you.
As heat energy is transferred through the saucepan, the water particles at the bottom
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(3)
(c)
Some energy is transferred from the hotplate to the air by thermal radiation. What is meant
by thermal radiation?
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(1)
(Total 6 marks)
Page 13 of 72
Q8.
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.
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(2)
Page 14 of 72
(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?
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(1)
(Total 6 marks)
Q9.
The diagram shows a side view of a double-glazed window.
Page 15 of 72
(a)
Use each of the terms in the box to explain how heat is lost from inside a house through
the window.
conduction
convection
radiation
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(3)
(b)
Besides heat, state one other form of energy that passes through double-glazed
windows.
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(1)
(c)
Explain why plastic foam cavity wall insulation cuts down energy transfer between warm
inner walls and cooler outer walls.
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(2)
(d)
When it rains the walls and windows of a house get wet.
Explain how the drying process can increase the cooling of the house.
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(2)
(Total 8 marks)
Page 16 of 72
Q10.
(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.
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(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?
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Cost of loft insulation = £ .................................................
(1)
(b)
What happens to the wasted energy?
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(1)
(Total 4 marks)
Page 17 of 72
Q11.
(a) The diagram shows an immersion heater used to heat water inside a tank. Heat is
transferred through the water by convection.
(i)
Draw arrows on the diagram to show the movement of the water in the tank when
the heating element is switched on.
(2)
(ii)
Explain how a convection current is set up in the water. The explanation has been
started for you.
When the heating element is switched on, the hot water nearest the element rises
because ...........................................................................................................
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(2)
(b)
The diagram shows two ways to reduce heat loss through the walls of a house.
(i)
How is the aluminium foil able to reduce heat loss?
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(1)
Page 18 of 72
(ii)
The plastic foam is good at reducing heat loss through the walls. Explain why.
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(3)
(c)
Evaporation is an important heat transfer process. When sweat evaporates, it takes heat
energy from your body. As humidity increases, you are more likely to feel hot and
uncomfortable. Explain why.
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(2)
(Total 10 marks)
Q12.
(a) The diagram shows two switches on a room heater. The heater has three power
settings. The power produced by two of the settings is given in the table.
Setting
Power
in kW
Low
0.5
Medium
1.5
High
(i)
When both switches are on, the heater works at the high power setting.
What is the power of the heater when it is switched to the high power setting?
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Power = ......................................................... kW
(1)
Page 19 of 72
(ii)
The heater is used on the medium power setting. It is switched on for three hours.
Use the equation in the box to work out the energy transferred from the mains to the
heater in three hours.
energy transferred
(kilowatt-hour, kWh)
=
power
(kilowatt, kW)
×
time
(hour, h)
Show clearly how you work out your answer.
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Energy transferred = ..................................... kWh
(2)
(iii)
Electricity costs 12 pence per kilowatt-hour.
Use the equation in the box to calculate how much the heater costs to use on
medium power for three hours.
total cost
=
number of kilowatt-hours
×
cost per kilowatt-hour
Show clearly how you work out your answer.
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Total cost = ................................................ pence
(2)
Page 20 of 72
(b)
The heater is used to warm a room.
The graph shows how the temperature of the room changes from the moment the heater
is switched on.
The heater was first used on the medium setting.
(i)
At what time was the heater setting changed to the high setting?
..............................................................
Give a reason for your answer.
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(2)
(ii)
From 7 pm until 10 pm, the temperature of the room is not changing.
Which one of the following statements gives the reason why the temperature of the
room is not changing?
Put a tick ( ) in the box next to your answer.
The room is losing energy slower than the heater supplies energy.
The room is losing energy as fast as the heater supplies energy.
The room is losing energy faster than the heater supplies energy.
(1)
(Total 8 marks)
Page 21 of 72
Q13.
(a) The diagram shows two switches on a room heater. The heater has three power
settings. The power produced by two of the settings is given in the table.
Setting
Power in
watts
Low
700
Medium
1400
High
(i)
When both switches are on, the heater works at the high power setting.
What is the power of the heater, in kilowatts, when it is switched to the high power
setting?
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Power = ......................................................... kilowatts
(1)
(ii)
The heater is used on the high power setting. It is switched on for 1½ hours.
Use the equation in the box to work out the energy transferred from the mains to the
heater in 1½ hours.
energy transferred
=
power
×
time
Show clearly how you work out your answer and give the unit.
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Energy transferred = ....................................................
(3)
(iii)
This type of heater is a very efficient device.
What is meant by a device being very efficient?
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(1)
Page 22 of 72
(b)
The graph shows how the temperature of a room changes during the 1½ hours that the
heater is used.
After 1 hour, the temperature of the room has become constant, even though the heater is
still switched on.
Explain why.
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(2)
(Total 7 marks)
Page 23 of 72
Q14.
The diagram shows a car radiator. The radiator is part of the engine cooling system.
Liquid coolant, heated by the car engine, enters the radiator. As the coolant passes through the
radiator, the radiator transfers energy to the surroundings and the temperature of the coolant
falls.
(a)
Why is the radiator painted black?
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(2)
Page 24 of 72
(b)
Different radiators have different numbers of cooling fins along the length of the radiator.
The sketch graph shows how the number of cooling fins affects the rate of energy transfer
from the radiator.
The number of cooling fins affects the rate of energy transfer from the radiator.
Explain how.
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(2)
(c)
When the car engine is working normally, 2 kg of coolant passes through the radiator each
second. The temperature of the coolant falls from 112 °C to 97 °C.
Calculate the energy transferred each second from the coolant.
Specific heat capacity of the coolant = 3800 J/kg °C.
Use the correct equation from the Physics Equations Sheet.
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Energy transferred each second = .............................................................. J
(3)
Page 25 of 72
(d)
On cold days, some of the energy transferred from a hot car engine is used to warm the
air inside the car. This is a useful energy transfer.
What effect, if any, does this energy transfer have on the overall efficiency of the car
engine?
Draw a ring around the correct answer.
decreases the
efficiency
does not change the
efficiency
increases the
efficiency
Give a reason for your answer.
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(2)
(Total 9 marks)
Q15.
The diagram shows the equipment a student used to investigate how the colour of a surface affects how fast
it emits (gives out) heat.
An equal volume of boiling water was poured into each metal can. The student then recorded the temperature of
the water in each can every minute for ten minutes.
(a)
(i)
Which of the following was a control variable in this investigation?
Put a tick ( ) in the box next to your answer.
The volume of boiling water.
The decrease in temperature of the water.
The outside colour of the metal can.
Page 26 of 72
(ii)
Give one advantage of using a temperature sensor and datalogger rather than a
thermometer to measure the temperature of the water.
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(1)
(b)
The student’s results for both cans are plotted on the graph.
Which line, A or B, shows how the temperature of the water inside the black-coloured
metal can changed?
Draw a ring around your answer.
A
B
Explain the reason for your answer.
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(2)
(c)
Some gardeners make soil darker by digging black soot into the soil. Other gardeners use
straw to protect plants from the cold.
(i)
Complete the following sentence by drawing a ring around the correct line in the box.
On a warm day, the temperature of darker coloured soil will increase
slower than
as fast as
the temperature of lighter coloured soil.
faster than
(1)
Page 27 of 72
(ii)
Give a reason for your answer to part (c)(i).
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(1)
(iii)
The statement in the box is false.
Straw keeps plants warm by trapping air.
This is because air is a good conductor.
Change one word in the statement to make the statement true.
Write down your new statement. The answer has been started for you.
This is because air is a ............................................................................
(1)
(Total 7 marks)
Q16.
A vacuum flask is designed to reduce the rate of heat transfer.
Page 28 of 72
(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.
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(2)
(b)
The diagram shows a gas flame patio heater.
(i)
Explain why the top surface of the reflecting hood should be a light, shiny surface
rather than a dark, matt surface.
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(2)
Page 29 of 72
(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.
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(1)
(Total 9 marks)
Q17.
The diagram shows the direction of heat transfer through a single-glazed window.
(a)
(i)
Name the process by which heat is transferred through the glass.
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(1)
(ii)
Explain how heat is transferred through the glass.
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(2)
Page 30 of 72
(b)
The rate of heat transfer through a window depends on the difference between the inside
and outside temperatures.
The graph shows the rate of heat transfer through a 1 m2 single-glazed window for a range
of temperature differences.
(i)
What is the range of temperature differences shown in the graph?
From ................................................ to ................................................
(1)
(ii)
A student looks at the graph and concludes:
‘Doubling the temperature difference doubles the rate of heat transfer.’
Use data from the graph to justify the student’s conclusion.
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(2)
Page 31 of 72
(iii)
A house has single-glazed windows. The total area of the windows in the house is
15 m2.
On one particular day, the difference between the inside and outside temperatures is
20 °C.
Use the graph to calculate the total rate of heat transfer through all of the windows on
this particular day.
Show clearly how you work out your answer.
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Rate of heat transfer = ........................................ J/s
(2)
(c)
A homeowner plans to replace the single-glazed windows in his home with double-glazed
windows. He knows that double-glazed windows will reduce his annual energy bills.
The table gives information about the double glazing to be installed by the homeowner.
Cost to buy and install
Estimated yearly
savings on energy bills
Estimated lifetime of the
double-glazed windows
£5280
£160
30 years
Explain, in terms of energy savings, why replacing the single-glazed windows with these
double-glazed windows is not cost effective.
To gain full marks you must complete a calculation.
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(2)
(Total 10 marks)
Page 32 of 72
Q18.
The diagram shows a metal pan being used to heat water.
Energy from the gas flame is transferred through the metal pan by conduction.
Explain the process of conduction through metals.
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(4)
(Total 4 marks)
Q19.
A student has read that a solar cell with a dirty surface will not work as well as a solar cell
with a clean surface.
To test the effect of a dirty surface on a solar cell, the student set up the following equipment.
Page 33 of 72
The student put the desk lamp a fixed distance from the solar cell. To represent the effect of a
dirty surface, the student covered the surface of the solar cell with pieces of tracing paper. Each
time the student added a piece of paper, she measured the output voltage of the solar cell.
(a)
The results taken by the student have been used to draw the graph below.
(i)
One of the results seems to be anomalous.
Draw a ring around the anomalous data point on the graph.
(1)
(ii)
The larger the number of sheets of tracing paper used, the lower the intensity of the
light reaching the solar cell.
Draw a ring around the correct answer in the box to complete the sentence.
a decrease in
A decrease in the intensity of the light reaching the solar cell causes
no change to
an increase in
(1)
Page 34 of 72
the output voltage from the solar cell.
(b)
People can buy panels of solar cells to generate electricity for their homes.
Any surplus electricity can be sold to the electricity supply company.
(i)
Give one environmental advantage of generating electricity using solar cells rather
than generating electricity in a coal-burning power station.
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(1)
(ii)
A homeowner pays £7600 to have solar panels fitted on the roof of their house.
The homeowner expects to save £950 each year from reduced energy bills and from
selling the electricity.
Assuming these figures to be correct, calculate the pay-back time for the solar
panels.
Show clearly how you work out your answer.
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Pay-back time = .................................................. years
(2)
(iii)
Draw a ring around the correct answer in the box to complete the sentence.
decrease
Allowing the surface of the solar panels to become very dirty will
not change
increase
the pay-back time.
(1)
(iv)
Explain your answer to part (b)(iii).
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(2)
(Total 8 marks)
Page 35 of 72
Q20.
The diagram shows a simple type of portable shower. The water container is a strong
plastic bag that is black on one side and white on the other. To warm the water, the bag is
placed on the ground in direct sunlight, with the black side facing the Sun.
(a)
(i)
Name the process by which heat is transferred from the Sun to the outside of the
bag.
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(1)
(ii)
Explain why the black side of the bag and not the white side should face the Sun.
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(2)
Page 36 of 72
(b)
The graph shows how the temperature of the water inside a full bag increases after the
bag is placed outside on a sunny day.
(i)
How long does it take for the water to reach 37 °C?
............................................
(1)
(ii)
Describe how the temperature of the water changes during the three hours.
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(1)
(c)
A different manufacturer makes the same type of portable shower but uses a bag with a
larger surface area. The bag is made from the same coloured plastics and holds the same
amount of water.
(i)
To compare the efficiency of the two bags at heating water, several variables need to
be controlled.
Name two variables that need to be controlled.
1 ............................................................................................................
2 ............................................................................................................
(2)
(ii)
The second bag has a larger surface area.
Draw a line on the graph to show how the temperature of the water inside the
second bag would change over the first hour.
Assume that the two bags are tested in exactly the same way.
(1)
(Total 8 marks)
Page 37 of 72
Q21.
(a)
Use the words from the box to complete the following sentences.
conduction
(i)
convection
radiation
The transfer of thermal energy (heat) by the movement of hot liquids
is called ............................................. .
(1)
(ii)
The transfer of thermal energy (heat) from one particle to another
is called ............................................. .
(1)
Page 38 of 72
(b)
A student set up the following equipment. The 3 metal plates are the same distance from
the heater. The surfaces of each of the 3 metal plates are different colours.
The student switched the heater on for 10 minutes. The thermometers were read before
the heater was switched on. The thermometers were read again just after the heaters
were switched off.
The readings are shown in the table.
(i)
Temperature before
switching on in °C
Temperature after
switching on in °C
1
19
21
2
19
29
3
19
23
Which set of readings, 1, 2 or 3, is most likely to have been taken from the
thermometer labelled L?
........................................
Give a reason for your answer.
...............................................................................................................
...............................................................................................................
(2)
Page 39 of 72
(ii)
Which one of the following was not a control variable in this experiment?
Put a tick ( ) in the box next to your answer.
the distance between the
heater and the metal
plates
the power of the heater
the temperature before the
heater was switched on
the colour of the metal
plates
(1)
(iii)
Suggest one advantage of using a temperature sensor, data logger and computer,
rather than a thermometer to carry out this experiment.
...............................................................................................................
...............................................................................................................
(1)
(c)
The picture shows a fire fighter putting out a forest fire. The fire fighter’s clothing has thick
thermal padding inside and a light coloured, fire proof, shiny layer outside.
(i)
What is the main way that heat is transferred through the air from the fire to the fire
fighter?
...............................................................................................................
...............................................................................................................
(1)
Page 40 of 72
(ii)
Why is the outside layer of the clothing shiny?
...............................................................................................................
...............................................................................................................
(1)
(d)
The graph shows the result of a laboratory test on two types of thermal padding. Each type
of padding was put onto a very hot metal surface and the temperature inside the padding
was taken every minute.
Which type of padding, M or N, would it be best to use inside the fire fighter’s clothing?
..........................................................................................
Give a reason for your answer.
........................................................................................................................
........................................................................................................................
(1)
(Total 9 marks)
Page 41 of 72
Q22.
The diagram shows the design of a solar cooker. The cooker heats water using infrared
radiation from the Sun.
(a)
Why is the inside of the large curved dish covered with shiny metal foil?
........................................................................................................................
........................................................................................................................
(1)
(b)
Which would be the best colour to paint the outside of the metal cooking pot?
Draw a ring around the correct answer.
black
silver
white
Give a reason for your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(c)
Why does the cooking pot have a lid?
........................................................................................................................
........................................................................................................................
(1)
Page 42 of 72
(d)
Calculate how much energy is needed to increase the temperature of 2 kg of water by 80 °
C.
The specific heat capacity of water = 4200 J/kg °C.
Use the correct equation from the Physics Equations Sheet.
........................................................................................................................
........................................................................................................................
........................................................................................................................
Energy = ...................................................................... J
(2)
(Total 6 marks)
Q23.
The vacuum flask shown has five features labelled, each one designed to reduce heat
transfer.
(a)
(i)
Which labelled feature of the vacuum flask reduces heat transfer by both conduction
and convection?
........................................................................................................................
(1)
Page 43 of 72
(ii)
Explain how this feature reduces heat transfer by both conduction and convection.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(b)
(i)
Which labelled feature of the vacuum flask reduces beat transfer by radiation?
........................................................................................................................
(1)
(ii)
Explain how this feature reduces heat transfer by radiation.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 6 marks)
Page 44 of 72
Q24.
The diagram shows two thermometers. The bulb of each thermometer is covered with a
piece of wet cotton wool. One of the thermometers is placed in the draught from a fan.
The graph shows how the temperature of each thermometer changes with time.
Page 45 of 72
(a)
Which of the graph lines, A or B, shows the temperature of the thermometer placed in the
draught?
Write the correct answer in the box.
Explain, in terms of evaporation, the reason for your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(3)
(b)
A wet towel spread out and hung outside on a day without wind dries faster than an
identical wet towel left rolled up in a plastic bag.
Explain why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 5 marks)
Page 46 of 72
Q25.
(a) In this question you will be assessed on using good English, organising information
clearly and using specialist terms where appropriate.
The diagram shows the structure of a vacuum flask.
A vacuum flask is designed to reduce the rate of energy transfer by heating processes.
Describe how the design of a vacuum flask keeps the liquid inside hot.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(6)
Page 47 of 72
(b)
Arctic foxes live in a very cold environment.
© Purestock/Thinkstock
Arctic foxes have small ears.
How does the size of the ears help to keep the fox warm in a cold environment?
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 8 marks)
Q26.
The diagram below shows a house which has not been insulated. The cost of the energy
lost from different parts of the house during one year is shown on the diagram.
Page 48 of 72
(a)
The total cost of the energy lost during one year is £1000.
(i)
What is the cost of the energy lost through the floor?
...........................................................................................................................
(2)
(ii)
Suggest one way of reducing this loss.
...........................................................................................................................
(1)
(b)
The table below shows how some parts of the house may be insulated to reduce energy
losses. The cost of each method of insulation is also given.
WHERE LOST
COST OF ENERGY
LOST PER YEAR (£)
METOD OF
INSULATION
COST OF
INSULATION (£)
roof
250
fibre-glass in loft
300
walls
350
foam filled cavity
800
windows
100
double glazing
4500
doors
150
draught proofing
5
(i)
Which method of insulation would you install first? Explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(ii)
Which method of insulation would you install last? Explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(Total 9 marks)
Page 49 of 72
M1.
(a)
(i)
Z
1
(ii)
X
1
(b)
(i)
moving randomly
1
(ii)
stronger than
1
(c)
(i)
evaporation
1
(ii)
any one from:
•
becomes windy
•
temperature increases
accept (becomes) sunny
“the sun” alone is insufficient
•
less humid
1
[6]
M2.
(a)
there are strong forces (of attraction) between the particles in a solid
accept molecules / atoms for particles throughout
accept bonds for forces
1
(holding) the particles close together
particles in a solid are less spread out is insufficient
1
or
(holding) the particles in a fixed pattern / positions
but in a gas the forces between the particles are negligible
accept very small / zero for negligible
accept bonds for forces
1
so the particles spread out (to fill their container)
accept particles are not close together
gas particles are not in a fixed position is insufficient
1
(b)
(i)
particles are (shown) leaving (the liquid / container)
accept molecules / atoms for particles throughout
accept particles are escaping
particles are getting further apart is insufficient
1
Page 50 of 72
(ii)
accept molecules / atoms for particles throughout
accept speed / velocity for energy throughout
particles with most energy leave the (surface of the) liquid
accept fastest particles leave the liquid
1
so the mean / average energy of the remaining particles goes down
1
and the lower the average energy (of the particles) the lower the temperature
(of the liquid)
1
[8]
M3.
absorber
1
reflector
1
emitter
1
[3]
M4.
(a)
1
1
(b)
3 and 4
or
1 and 2
1
(c)
U-values for the 20 mm windows are the same or higher
than those for the 16 mm windows
1
therefore the 20 mm windows are no more energy efficient
than 16 mm windows
accept so the 16 mm windows are as energy efficient as 20 mm
windows
1
(d)
1 and 2
must have both and no other
1
Page 51 of 72
(e)
Type B glass transmits less infrared than Type A glass
accept radiation / heat for infrared
accept Type B glass absorbs more infrared than Type A glass
1
and as infrared has a heating effect the conservatory will
remain cooler
1
[7]
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)
because black is a good absorber of radiation
1
there will be a faster transfer of energy
allow the temperature of the water rises faster
1
(b)
16 800 000
allow 1 mark for substitution into correct equation
ie 100 × 4200 × 40
2
(c)
7 allow
ecf from part (b)
1
Page 52 of 72
(d)
Marks awarded for this answer will be determined by the
Quality of Written Communication (QWC) as well as the
standard of the scientific response.
No relevant content.
0 marks
There is a brief description of the advantages and disadvantages
of using solar energy to heat the water rather than using an
electric immersion heater, including either advantages or
disadvantages from the examples below.
Level 1 (1-2 marks)
There is a description of some of the advantages and
disadvantages of using solar energy to heat the water
rather than using an electric immersion heater, with at
least one advantage and one disadvantage from the
examples below.
Level 2 (3-4 marks)
There is a clear, balanced and detailed description of the
advantages and disadvantages of using solar energy to
heat the water rather than using an electric immersion
heater, with a minimum of two advantages and two
disadvantages from the examples below.
Level 3 (5-6 marks)
examples of the points made in the response
advantages
accept specific examples of polluting gases
•
a renewable energy source
•
energy is free
•
does not pollute the atmosphere
•
no fuel is burnt
•
energy can be stored (in the water)
disadvantages
accept unreliable energy source
•
only available in daylight hours
•
availability fluctuates
•
insufficient hours of sunlight in some countries
•
average low intensity in some countries
[11]
Page 53 of 72
M7.
(a)
ions / electrons gain (kinetic) energy
accept atom / particles / molecules for ion
accept ions vibrate faster
accept ions vibrate with a bigger amplitude
accept ions vibrate more
do not accept ions move faster
1
(free) electrons transfer energy by collision with ions
or energy transferred by collisions between vibrating ions
1
(b)
move faster or take up more space
do not accept start to move / vibrate
1
(warmer) water expands or becomes less dense (than cooler water)
do not accept answers in terms of particles expanding
1
warm water rises (through colder water) or colder water falls to take its place
1
(c)
transfer of energy by waves / infrared (radiation)
accept rays for waves
do not accept transfer of energy by electromagnetic waves
ignore reference to heat
1
[6]
M8.
(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]
Page 54 of 72
M9.
(a)
(heat) is conducted through the glass
the answers must be within the context of the question
1
(heat) passes through glass and air by radiation
both glass and air required
1
(heat) crosses the air gap by convection
mention of conduction through air is neutral
1
(b)
any one from
light
accept sunlight
gamma rays
X-rays
radio
accept sound or ir or microwaves or electromagnet waves
1
(c)
any two from
cuts down convection currents
accept stops air moving
air pockets trap air (from moving)
accept has air pockets
do not accept stops heat moving or traps heat
foam is a poor conductor
air in the foam is a good insulator
accept air is a good insulator in air pockets for both marks
2
(d)
evaporation (of the water)
do not accept rain is cold
1
takes energy from the house
accept takes heat away or higher energy molecules leave first
1
[8]
M10.
(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
Page 55 of 72
(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]
M11.
(a)
(i)
convection current correctly shown
with arrows extending to above
insulation label line
circulation must show water rising in the left half of the tank accept
continuous or broken arrows must be at least one arrow up and
one arrow down
allow 1 mark for correct diagram which does not extend high
enough
2
(ii)
it expands or it gets less dense
do not allow hot water rises
do not accept explanation in terms of molecules expanding or
changing density
do not accept lighter or heavier
1
more dense water falls
allow cold water falls if qualified with a suitable reason
1
(b)
(i)
reflects heat back into the room or where it came from
accept infrared or radiation or energy for heat
accept bounce for reflect if in correct context
1
(ii)
air is a (good) insulator or poor conductor or air stops conduction
do not accept plastic foam is a good insulator or bad conductor
1
air is trapped
1
convection loss reduced or stopped
1
(c)
two out of the following three:
any answer which gains credit must contain a comparison
rate of evaporation decreases
accept less sweat can evaporate or evaporation is more difficult
Page 56 of 72
less heat energy removed from the body
higher humidity the less water vapour can be absorbed (into the air)
accept sweat for water vapour
do not credit description of high humidity
accept a correct answer in terms of dynamic equilibrium
2
[10]
M12.
(a)
(i)
2(.0)
accept 2000 W or 2000 watt(s)
accept answer given in table
do not accept 2000
1
(ii)
4.5
allow 1 mark for correct substitution
ie 1.5 × 3
allow 1 mark for the answers 1.5 or 6(.0)
2
(iii)
54
or
their (a)(ii) × 12 correctly calculated
allow 1 mark for correct substitution
ie 4.5 × 12
or
their (a)(ii) × 12
allow 1 mark if correct answer is given in pounds eg £54
2
(b)
(i)
6 pm
1
temperature starts to rise faster
only scores if 6 pm given
or
graph (line) is steeper / steepest
it refers to graph gradient or temperature
accept answers in terms of relative temperature rise
eg 5 to 6 pm 2 °C rise, 6 to 7 pm 6 °C rise
accept temperature rises sharply / rapidly / quickly
do not accept temperature starts to rise
1
(ii)
middle box ticked
1
[8]
Page 57 of 72
M13.
(a)
(i)
2.1
correct answer only
1
(ii)
3.15
or
their (a)(i) × 1.5 correctly calculated
allow 1 mark for correct substitution
ie 2.1 × 1.5
or
their (a)(i) × 1.5
2
kilowatt-hour
accept kWh
or
a substitution 2100 × 5400 scores 1 mark
2100 × 5400 incorrectly calculated with answer in joules scores 2
marks
an answer of 11 340 000 scores 2 marks
an answer of 11 340 000 J scores 3 marks
1
(iii)
most (input) energy is usefully transformed
accept does not waste a lot of energy
accept most of the output / energy is useful
do not accept it does not waste energy
1
(b)
the room is losing energy / heat
1
at the same rate as the heater supplies it
this mark only scores if the first is scored
do not accept heater reaches same temperature as room /
surroundings
rate of heat gain = rate of heat loss scores both marks
1
[7]
M14.
(a)
(matt) black is a good emitter of infrared / radiation
accept heat for infrared / radiation
ignore reference to good absorber
attracts heat negates this marking point
1
to give maximum (rate of) energy transfer (to surroundings)
accept temperature (of coolant) falls fast(er)
accept black emits more radiation for 1 mark
black emits most radiation / black is the best emitter of radiation for
2 marks
1
Page 58 of 72
(b)
the fins increase the surface area
accept heat for energy
1
so increasing the (rate of) energy transfer
or
so more fins greater (rate of) energy transfer
1
(c)
114 000
allow 1 mark for correct temperature change, ie 15 (°C)
or
allow 2 marks for correct substitution, ie 2 × 3 800 × 15
answers of 851 200 or 737 200 gain 2 marks
or
substitution 2 × 3800 × 112 or 2 × 3800 × 97 gains 1 mark
an answer of 114 kJ gains 3 marks
3
(d)
increases the efficiency
1
less (input) energy is wasted
accept some of the energy that would have been wasted is
(usefully) used
or
more (input) energy is usefully used
accept heat for energy
1
[9]
M15.
(a)
(i)
The volume of boiling water.
1
(ii)
any one from:
•
(more) precise
do not accept better (reading)
•
accurate
•
reliable
do not accept thermometer is unreliable
•
removes human / reading error
accept easier to read
accept take temperature more frequently
1
Page 59 of 72
(b)
B
marks are for the explanation
temperature falls faster
this mark point cannot score if A chosen
1
because black is a better / good emitter
ignore reference to better absorber
accept for both marks an answer in terms of why A is the white can
1
(c)
(i)
faster than
1
(ii)
darker / black surfaces absorb heat faster
accept black is a better / good absorber
dark surfaces attract heat negates this mark
1
(iii)
air is a bad / poor conductor
or
air is a good insulator
accept air is an insulator
1
[7]
M16.
(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 60 of 72
(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]
M17.
(a)
(i)
conduction
1
Page 61 of 72
(ii)
atoms gain (kinetic) energy
accept particles / molecules for atoms
do not accept electrons for atoms
or
atoms vibrate with a bigger amplitude
accept vibrate faster / more
do not accept start to vibrate
or
atoms collide with neighbouring atoms
1
transferring energy to (neighbouring / other) atoms
do not accept heat for energy
or
making these other atoms vibrate with a bigger amplitude
accept faster / more for bigger amplitude
mention of (free) electrons moving and passing on energy negates
this mark
1
(b)
(i)
5 (°C) to 25 (°C)
either order
1
(ii)
a correct example of doubling temperature difference doubling heat transfer
eg going from 5 to 10 (°C) difference doubles heat transfer from 30 to 60 (J/s)
accept for heat transfer number of joules / it
allow 1 mark for correctly reading 1 set of data eg at 5 °C the heat
transfer is 30
or
for every 5°C increase in temperature difference heat transfer
increases by 30 (J/s)
no credit for stating they are directly proportional
2
(iii)
1800
allow 1 mark for obtaining heat transfer value = 120
2
(c)
payback time calculated as 33 years
calculations must be correct to score the first mark point
explanations must relate to it not being cost effective
1
Page 62 of 72
this is greater than lifetime of windows
or
total savings (over 30 years) = £4800 (1)
this is less than cost of windows (1)
or
= 176 (1)
this is more than the yearly savings (1)
1
[10]
M18.
accept atoms / particles for ions throughout
(a metal has) free electrons
accept mobile for free
1
(kinetic) energy of (free) electrons increases
accept energy of ions increases
accept ions vibrate with a bigger amplitude
accept ions vibrate more
do not accept electrons vibrate more
1
(free) electrons move faster
1
or
electrons move through metal
accept electrons collide with other electrons / ions
(so) electrons transfer energy to other electrons / ions
accept ions transfer energy to neighbouring ions
1
[4]
M19.
(a)
(i)
correct data point identified (4, 0.96)
1
(ii)
a decrease in
1
Page 63 of 72
(b)
(i)
no / less atmospheric pollution
accept specific examples eg no CO2 / greenhouse gases produced
accept no harmful gases / fumes
accept reduced pollution from transportation (of coal)
accept does not contribute to global warming
it / they refers to solar cells
do not accept no / less pollution
does not harm the environment is insufficient
it is a renewable energy source is insufficient
1
(ii)
8
allow 1 mark for showing correct method ie
subsequent step is shown
provided that no
2
(iii)
increase
1
(iv)
these marks can score even if (b)(iii) is wrong
less / no electricity generated
accept energy for electricity
accept reduced power / voltage output
1
(because) lower light intensity (hitting solar panel / cell)
or
so decreases money paid / gained (from selling electricity)
allow less light / sun (hitting solar panel / cell)
1
[8]
M20.
(a)
(i)
radiation
ignore thermal / infrared
1
(ii)
black is a better / good absorber (of heat / radiation)
ignore reference to black being a good emitter
black absorbs heat is insufficient
do not accept black attracts / absorbs the Sun
do not accept black attracts heat
1
Page 64 of 72
(so) temperature rises faster
must be an indication of heating up quicker
or
white is a worse / poor absorber (of heat / radiation) (1)
accept white is a better / good reflector (of heat / radiation)
(so if white faces) temperature would rise slower (1)
ignore any reference to light
1
(b)
(i)
1.2 (hours) or 1 hour 12 minutes
no tolerance
1
(ii)
increases (rapidly at first then increases at a slower rate)
do not accept increases at a steady rate
1
(c)
(i)
any two from:
•
(fill with) same mass / volume / amount of water
•
same level of (sun)light / sunshine
accept same heat / light source
accept same place
•
outside for the same (length of) time
•
outside at same time (of day / year)
•
initial water temperature
•
the side of the bag facing the Sun
do not accept any factors to do with the construction of plastic
bags eg thickness
2
(ii)
curved line drawn above given line
both lines must start from the same point
ignore if continues beyond one hour or levels off after 1 hour
do not accept a straight line
1
[8]
M21.
(a)
(i)
convection
1
(ii)
conduction
1
(b)
(i)
2
1
Page 65 of 72
black is the best absorber (of thermal energy / heat)
accept black is the best emitter (of thermal energy / heat)
note that a comparative is needed (eg better or best)
1
(ii)
the colour of the metal plates
1
(iii)
any one from:
•
more precise / accurate / reliable
do not accept better reading
do not accept thermometer is unreliable
•
can measure continuously
•
take many readings in a small time
•
removes (human) reading error
accept easier to read
•
can compare / draw graphs automatically
•
records data automatically
1
(c)
(i)
radiation
accept radiates
accept infra red (IR) waves
do not accept heat waves
1
(ii)
to reflect (heat away from the fire fighter)
accept it reflects
accept it is a poor absorber (of thermal radiation / heat)
do not accept deflect / bounce for reflect
1
(d)
N
the mark is for the reason which does not score if M is chosen
transfers / absorbs less heat
or
gives smallest increase in temperature
accept will keep fire fighters cooler
accept N is cooler (after 15 minutes)
an answer N goes up to 52°C and M goes up to 100°C is
insufficient
1
[9]
Page 66 of 72
M22.
(a)
to reflect (the infrared)
accept (shiny surfaces) are good reflectors
ignore reference to incorrect type of wave
1
(b)
black
1
best absorber (of infrared)
answer should be comparative
black absorbs (infrared) is insufficient
accept good absorber (of infrared)
ignore reference to emitter
ignore attracts heat
ignore reference to conduction
1
(c)
to reduce energy loss
accept to stop energy loss
accept heat for energy
accept to stop / reduce convection
or
so temperature of water increases faster
accept to heat water faster
accept cooks food faster
or
reduces loss of water (by evaporation)
1
(d)
672 000
allow 1 mark for correct substitution, ie 2 × 4200 × 80 provided no
subsequent step shown
2
[6]
M23.
(a)
(i)
vacuum
do not allow stopper
1
(ii)
(absence of particles) means no (transfer of energy between)
particles for conduction
accept particles or atoms or molecules or electrons
1
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no movement of molecules for (transfer of energy by) convection
accept particles/atoms/electrons
if answer to (a)(i) is correct: then in (a)(ii) have stated
‘conduction and convection both need a
medium/particles/materials’ = 2 marks
(If medium is specified, it must be correct, conduction can be solid,
liquid or gas, convection must be liquid or gas)
if answer to (a)(i) is incorrect then in (a)(ii) have stated ‘conduction
and convection both need a medium...’= 1 mark, unless further
qualified by stating about absence of particles, in which case get a
second mark.
1
(b)
(i)
silvered surface
accept silver surface
1
(ii)
silvered is a bad emitter/radiator
1
surface reflects heat/energy/radiation (at inner and outer surface)
or is a bad absorber (of energy)
accept bounces off
1
[6]
M24.
(a)
B
no mark for B - marks are for the explanation
first two mark points can score even if A is chosen
draught increases (the rate of) evaporation
accept more evaporation happens
accept draught removes (evaporated) particles faster
do not accept answers in terms of particles gaining energy from
the fan / draught
1
evaporation has a cooling effect
accept (average) kinetic energy of (remaining) particles decreases
1
so temperature will fall faster / further
1
(b)
larger surface area
1
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increasing the (rate of) evaporation
accept more / faster evaporation
accept easier for particles to evaporate
or
for water to evaporate from
accept more particles can evaporate
accept water / particles which have evaporated are trapped
(in the bag)
answers in terms of exposure to the Sun are insufficient
1
[5]
M25.
(a) Marks awarded for this answer will be determined by the Quality of Written
Communication (QWC) as well as the standard of the scientific response. Examiners
should also refer to the information in the Marking guidance.
0 marks
No relevant content.
Level 1(1-2 marks)
There is a basic explanation of one feature
or
a simple statement relating reduction in energy transfer to one feature.
Level 2(3-4 marks)
There is a clear explanation of one feature
or
a simple statement relating reduction in energy transfer to two features.
Level 3(5-6 marks)
There is a detailed explanation of at least two features
or
a simple statement relating reduction in energy transfer to all four features.
Page 69 of 72
Examples of the points made in response
extra information
accept throughout:
heat for energy
loss for transfer
plastic cap:
•
plastic is a poor conductor
accept insulator for poor conductor
•
stops convection currents forming at the top of the flask so stopping energy
transfer by convection
•
molecules / particles evaporating from the (hot) liquid cannot move into the
(surrounding) air so stops energy transfer by evaporation
•
plastic cap reduces / stops energy transfer by conduction / convection /
evaporation
glass container:
•
glass is a poor conductor so reducing energy transfer by conduction
•
glass reduces / stops energy transfer by conduction
vacuum:
•
both conduction and convection require a medium / particles
•
so stops energy transfer between the two walls by conduction and convection
•
vacuum stops energy transfer by conduction / convection
silvered surfaces:
•
silvered surfaces reflect infrared radiation
accept heat for infrared
•
silvered surfaces are poor emitters of infrared radiation
•
infrared radiation (partly) reflected back (towards hot liquid)
•
silvered surfaces reduce / stop energy transfer by radiation
6
(b)
(the ears have a) small surface area
ears are small is insufficient
1
so reducing energy radiated / transferred (from the fox)
accept heat lost for energy radiated
do not accept stops heat loss
1
[8]
Page 70 of 72
M26.
(a)
(i)
£150
gets 2
Else 1000 – (250 + 350 + 100 + 150) or 1000 – 850
gets 1
2
(ii)
(Named) floor covering
OR Insulation under floor
for 1 mark
1
(b)
(i)
Draught proof doors or fibre glass in loft or in cavity
For draught proofing
gains 1 mark
Very low cost/easy to install
Repays for itself quickly/cost recuperated quickly
Reasonable energy saving
any 2 for 1 mark each
For loft insulation
Second lowest installation cost/easy to install
Reasonable large energy savings for this cost
Reasonable payback time
gains 1 mark
For foam filled cavity
Biggest energy/cash saving
Cost effective
any 2 for 1 mark each
3
(ii)
Double glazing
gains 1 mark
Costs most
Saves least energy
Least cost effective
any 2 for 1 mark each
3
[9]
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