Use words from the box to answer the questions below. chemical electrical gravitational potential. kinetic light sound thermal

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1 Energy Transfer Exam Practice Q1. In a power station, coal can be used to generate electricity. Drayton Manor High School (a) Use words from the box to answer the questions below. chemical electrical gravitational potential kinetic light sound thermal (i) What is the useful energy transfer when coal is burnt?... energy is transferred to... energy Some of the energy stored in coal is wasted when it is burnt. Give the name of one type of energy released that is not useful.... Wind turbines are also used to generate electricity. The wind turns the turbine blades and the turbine blades turn a generator. Use words from the box opposite. Complete the sentence to show the useful energy transfer in a wind turbine and generator.... energy is transferred to... energy (c) Suggest one disadvantage of using wind to generate electricity. (d) Sugar cane is a plant. The sugar from the cane is used to make alcohol. Alcohol is a fuel. (i) Which energy source do plants use to produce sugar?... Is sugar cane a renewable or non-renewable source of energy? Tick one box. Page 1

2 renewable source non-renewable source Give a reason for your answer.... maximum 7 marks Q2. 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 (3) Complete the following sentence using one of the words from the box. chemical heat kinetic sound Energy that is not usefully transformed by the fan heater is wasted as... energy. (1) (c) The table gives information about two different fan heaters. Useful energy transferred each second in joules Wasted energy transferred each second in joules Fan heater L Fan heater M Complete the following sentence by drawing a ring around the line in the box that is correct. Fan heater L is more efficient than has the same efficiency as fan heater M. Page 2

3 is less efficient than (1) (Total 5 marks) Q3. Meera used the Internet to find out about energy resources. The drawing below shows what Meera saw on her computer screen. (a) Coal is a fossil fuel. Give the names of two other fossil fuels in the list on the screen....and... 2 marks (i) Wave energy is an example of a renewable energy resource. From the list on the screen above choose two other renewable energy resources....and... 2 marks Meera found out how wave energy can be used to generate electricity. She saw the diagram below on the Internet. Page 3

4 Each box below shows a stage in generating electricity. A The air turns the turbine. B The turbine turns the generator. C The waves move up the chamber. D The generator produces electricity. E The waves push the air up the chamber. On the lines below write the letters of the stages in the correct order. Two have been done for you....c a Q4. The drawing below shows a solar panel fixed to the roof of a house in Britain. 2 marks (a) Daniel measured the energy output from this solar panel during one day in June. The graph below shows his results. Page 4

5 (i) Why does the energy output from the solar panel vary during the day? Daniel used the solar panel to run a motor. The motor needs 0.7 kj/s to run at full speed. Use the graph to find out how long Daniel s motor would run at full speed.... hours Daniel measured the energy output from a different solar panel. This type of solar panel turns so that it always faces the Sun. The graph below shows the energy output for this panel during one day in mid-summer. Page 5

6 (i) On the graph above draw another curve to show how the energy output for this solar panel might vary on a day in mid-winter. 2 marks Between 7am and 7pm the solar panel turns through an angle of 180. Calculate the angle the solar panel turns through each hour degrees maximum 5 marks Q5. (a) The diagram shows the energy transformations produced by a TV. (i) Use the information in the diagram and the equation in the box to calculate the efficiency of the TV. efficiency = Show clearly how you work out your answer. Page 6

7 Drayton Manor High School Efficiency =... (2) What eventually happens to the useful energy transferred by the TV? (1) Electrical appliances left on standby use energy. The bar chart shows the power for the appliances that one family leaves on standby when they go on holiday. The family is on holiday for a total of 175 hours (i) Use the information in the bar chart and the equation in the box to calculate the energy wasted by leaving the compact stereo on standby while the family is on holiday. energy transferred (kilowatt-hour, kwh) = power (kilowatt, kw) time (hour, h) Show clearly how you work out your answer Energy wasted =... kilowatt-hours (2) 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. Page 7

8 total cost = number of kilowatt-hours cost per kilowatt-hour Show clearly how you work out your answer.... Cost =... p (1) (c) A headline from a recent newspaper article is shown below. Explain why leaving appliances on standby damages the environment Q6. John used an electrical heater to heat a cup of water. He kept stirring the water. When the temperature reached 20 C, he started his stopwatch and measured the temperature of the water every half minute. (2) (Total 8 marks) He switched off the heater after 4 minutes, but continued to record the temperature. His results are shown in the table. One measurement is missing and another appears to be wrong. Time (minutes) Temperature (ºC) Page 8

9 (a) Use the results in the table to draw a graph on the grid. Label the axes. Plot the points and draw a smooth curve of best fit. 4 marks From your curve, estimate the temperature of the water after three minutes.... C maximum 5 marks Q7. The drawing below shows a garden water feature. It is solar-powered. Page 9

10 The solar cell absorbs energy from the Sun. The solar cell is connected to a motor in the bowl. The motor drives a pump. Water is pumped up to the jug and it flows back down to the bowl. (a) Use the information above to help you to complete the following sentences. Choose words from the list. (i) The useful energy change in the solar cell is from light to... energy. The useful energy change in the motor is from electrical energy to... energy. (iii) As the water flows from the jug to the bowl... energy is changed into... energy. 2 marks Give one advantage and one disadvantage of using a solar cell to power the water feature. advantage disadvantage maximum 6 marks Q8. Keith has a wind-up radio. It does not use batteries. It is powered by a steel spring. Page 10

11 (a) Keith winds up the spring. As the spring unwinds, potential energy in the spring is transferred to a generator, which then turns. The generator provides electrical energy for the radio. Fill the gaps in the sentences below to show the useful energy changes which take place in the generator and the speaker. (i) As the generator turns,... energy is changed to electrical energy. In the speaker, electrical energy is changed to... energy. When Keith turns the volume up so that the radio is louder, the spring unwinds more quickly. Why does the spring unwind more quickly? (c) The radio has a solar cell which can also provide electrical energy. Keith winds up his radio and takes it outside without changing the volume. The steel spring unwinds more slowly when sunlight falls on the solar cell. Explain why (d) The wind-up radio was designed for use in poorer countries. Suggest why wind-up radios are useful in poorer countries Page 11

12 M1. (a) (i) chemical answers must be in the correct order thermal accept kinetic heat is insufficient movement is insufficient any one from sound light kinetic electrical answers must be in the correct order both answers are required for the mark movement is insufficient for kinetic (c) any one from the wind speed varies accept it depends on the weather sometimes the wind does not blow accept the wind is unreliable the wind cannot be controlled accept it varies accept it could be too windy responses that do not refer to wind, such as they spoil the landscape or they kill birds or they are too noisy or interfere with TV and radio signals are insufficient (d) (i) Sun(light) accept light accept solar (energy) do not accept heat photosynthesis is insufficient 1 (L5) 1 (L5) renewable source both the correct answer and a correct explanation are required for the mark you can grow more plants accept you grow it (again) do not accept you can use it again it is a biofuel is insufficient M2. (a) iron hairdryer kettle answers can be in any order Page

13 sound Drayton Manor High School 1 (c) is more efficient than 1 [5] M3. (a) oil natural gas accept gas answers may be in either order 1 (L4) 1 (L4) (i) any two from answers may be in either order wind solar tidal biomass geothermal C E A B D if all three letters are correct, award two marks if one letter is correct, award one mark M4. (a) (i) any one from 2 (L4) 2 (L4) [6] the Earth rotates accept the Sun appears to move across the sky accept the Sun is in a different position at different times of day the amount of sunlight varies accept different cloud cover the angle of the Sun varies accept in the middle of the day the energy received is greatest do not accept in the middle of the day the Sun is hottest or brightest 6.0 accept any number from 5.8 to 6.2 (i) a graph starting after 6 am and ending before 6 pm a line below the existing line and flat or reaching a maximum between 12 noon and 1 pm 15 accept Page 13

14 [5] M5. (a) (i) 0.6 accept 60 % allow for useful energy = 480 answer 0.6 with any unit or 60 gains only 2 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 (i) 1.75 allow for converting to kw answers of 0.7, 0.525, 0.35, 0.875, 1.05, 5.25 gains answers of 1750 or 17.5 gains 2 21p or 0.21 or their (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 M6. (a) X-axis: time (minutes) 2 [8] Y-axis: temperature ( C) appropriate scales such as 2 cm represents 10 C, 2 cm represents 1 minute 11 points plotted to within half a small square a smooth curve of best fit (not dot-to-dot) pupils can gain credit for correct responses to other parts if the axes are wrongly labelled both answers are required for the mark units are required for the mark at least one zero must be included at the origin Page 14

15 an answer consistent with the drawn curve accept a tolerance of one small square [5] M7. (a) (i) electrical 1 (L5) kinetic accept movement (iii) gravitational potential accept gravitational or potential kinetic or sound or thermal accept heat for thermal accept for two marks kinetic into sound or kinetic into thermal answers must be in the correct order 1 advantage the energy will always be replaced accept it will not run out it is renewable accept it does not use fuel or mains electricity it is free to run accept it is cheap a battery might leak accept no pollution with a solar cell 1 (L5) disadvantage if the Sun goes in the pump will stop it will not work at night or in the dark accept it must be in the Sun to work accept it is not sunny all the time do not accept can be used again M8. (a) (i) kinetic accept movement or motion 1 (L5) [6 sound accept kinetic or movement or motion any one from answers must refer to energy or power loud sounds dissipate more energy than quieter sounds accept energy is used or needed more quickly energy is transferred more quickly accept it is using more power or more energy is Page 15

16 transferred per second more potential or kinetic energy is converted to sound accept more energy is converted to sound accept it is using or transferring more energy accept it produces more electrical energy do not accept it uses more electricity (c) any one from solar energy or light energy is used accept the radio is run by sunlight or light less energy is provided by or taken from the spring accept the light provides a second source of energy energy is provided by the solar cell accept the radio is run by the Sun accept the radio has two sources of energy (d) any one from batteries or mains electricity are not available batteries or mains are not needed people cannot afford batteries or mains electricity accept the energy resource is free accept they are cheap to run they are cheap is insufficient [5] Page 16