(3) (1) (total 4 marks) - tasker milwardscience.taskermilward.org.uk/mod1/ks4physics/aqa/p1 part...

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)

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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.

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(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)

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(b) Calculate how efficient the car engine is at transferring the energy from petrol into useful movement.

[Show your working].

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.....................................................................................................................................

..................................................................................................................................... (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.

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.....................................................................................................................................

..................................................................................................................................... (4)

(Total 9 marks)

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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)

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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.

.....................................................................................................................................

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..................................................................................................................................... (2)

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(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.

(1)

Type of electromagnetic radiation

Tick ( )

gamma

infra red

ultraviolet

X-ray

(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)

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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)

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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.

(i) The energy input to the solar cells is ................................................ energy. (1)

(ii) The useful energy output from the solar cells is ........................................ energy. (1)

chemical electrical heat light sound

(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)

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(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)

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(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.

(1)

Water heated to produce steam

→ Steam turns a turbine

→ Turbine turns a coil in a

..........................

→ Electricity is produced

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(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)

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(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)

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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)

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(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)

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(a) The table gives information about some ways of reducing the energy consumption in a house.

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.

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..................................................................................................................................... (3)

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

(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.

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..................................................................................................................................... (2)

(Total 5 marks)

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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)

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(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.

Air is a good ........................................... . When trapped between two sheets of glass it

reduces heat loss by .......................................... and .................................................... (3)

conduction conductor convection evaporation insulator radiation

(c) The table gives information about three types of house insulation.

Type of 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

(i) Use the information in the table to calculate the payback time for cavity wall insulation.

........................................................................................................................... (1)

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(ii) Explain why people often install loft insulation before installing double glazing or cavity wall insulation.

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........................................................................................................................... (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.

A washing machine is designed to transform electrical energy into heat and

......................................................... energy (1)

kinetic light sound

(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

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(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)

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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)

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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.

Energy that is not usefully transformed by the fan heater is wasted as

................................................. energy. (1)

chemical heat kinetic sound

(c) The table gives information about two different fan heaters.

Complete the following sentence by drawing a ring around the line in the box that is correct.

(1) (Total 5 marks)

Useful energy

transferred each second in joules

Wasted energy transferred each second in joules

Fan heater L 1200 10

Fan heater M 1200 20

Fan heater L

is more efficient than

has the same efficiency as

is less efficient than

fan heater M.

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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)

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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.

Assume 1 kilowatt-hour (kWh) of energy costs 12 p.


.....................................................................................................................................

.....................................................................................................................................

Extra cost per year = £ .............................. (2)

total cost = number of kilowatt-hours × cost per kilowatt-hour

(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.


.....................................................................................................................................

.....................................................................................................................................

Price reduced by = £ ........................................ (2)

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(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 = .............................. (2)

efficiency =

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(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 wasted = .............................. kilowatt-hours (2)

energy transferred (kilowatt-hour, kWh)

= power (kilowatt, kW)

× time (hour, h)

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(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.


...........................................................................................................................

Cost = .............................. p (1)

total cost = number of kilowatt-hours × cost per kilowatt-hour

(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)

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(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.

(1) (Total 4 marks)

Television A has

a higher efficiency than

the same efficiency as

a lower efficiency than

television B.

Q21. The pictures show three different types of electric heater.

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(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 = .............................. kilowatt-hours (2)

energy transferred = power × time

(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)

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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.

(2)

(ii) Explain why the vacuum between the glass walls of the flask reduces heat transfer by conduction and convection.

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

........................................................................................................................... (2)

Feature Conduction Convection Radiation

vacuum

silvered surfaces

plastic cap

(b) The diagram shows a gas flame patio heater.

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(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.

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(a) Use words from the box to complete the following sentence.

Solar cells are designed to transform .............................................................. energy into

.............................................................. energy. (2)

electrical heat light sound

(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.


...........................................................................................................................

...........................................................................................................................

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)

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(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.

Energy input Electrical

Useful energy output

Kinetic

Power rating 1200 watts

Efficiency 0.8

(a) 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.

........................................................................................................................

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Cost of waste energy = ...................................... p (4)

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(b) Explain what happens to the waste energy.

........................................................................................................................

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........................................................................................................................

........................................................................................................................ (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

(2)

boiler condenser furnace generator

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(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

(1)

decrease.

not change.

increase.

carbon dioxide emitted into the atmosphere will

(d) Some types of power station generate electricity by burning a biofuel.

Give one example of a biofuel.

........................................................................................................................ (1)

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(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)

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M1. (a) (i) 15*

(ii) 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]

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(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

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(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]

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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]

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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]

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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

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(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 CO

2 or global warming

ignore reference to conservation of energy 1

[5]

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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

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(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

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(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

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(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

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(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

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)

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]

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

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(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

of 52

(e) (nuclear) fission 1

[7]

of 52

(3) (1) (total 4 marks) - tasker milwardscience.taskermilward.org.uk/mod1/ks4physics/aqa/p1 part...

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