UNIT 9

1. UNIT 9 Vocabulary • Types of pollution • Environmental effects Grammar and functions • Expressing degree • Graphs & Figures • Revision of the grammar structures

2. ORAL PRACTICE • Give examples of how we pollute our air, land and water • How can we protect the environment? • Are you a green person? • What effects are attributed to global warming? • Describe the greenhouse effect. How could it be reduced?

3. LISTENING 1-Environmental pollution is the CONTAMINATIONOF THE AIR, LAND AND WATER CAUSED BY HUMAN PRODUCTS. 2-a) CHEMICALSRELEASEDBYINDUSTRIALPROCESSES b)EXHAUST FROM GASOLINE-POWERED VEHICLES LIKE AUTOMOBILES, c) REFUSE AND GASES EMITTED BY FACTORIES, d)sewage and GARBAGE DISPOSED OF BY CITIES, e) PESTICIDES USED IN AGRICULTURE. 3-THE AMOUNT OF RELEASED POLLUTANTS. 4- a) CONSERVATION EFFORTS, SUCH AS RECYCLING b) NEW TECHNOLOGIES ALLOW INDUSTRY TO RELEASE FEWER POLLUTANTS INTO THE ENVIRONMENT. 5-The long-term effects of pollution are not yet PRECISELYknown, but it is WIDELYbelieved by scientists that GLOBAL WARMING - THE HEATING OF THE EARTH’S ATMOSPHERE AS A RESULT OF THE GREENHOUSE EFFECT is a threat to most forms of life on the planet .

4. ADJ/ADV • Quantity(+N):all/every/each| most|many/much| some, several| (a) few/(a) little | no (+N) /none (PRONOUN)/not any • Frequency(+VB):always|usual(ly), normal(ly), general(ly)|often, frequent(ly)| sometimes, occasional(ly)| rare(ly), seldom, hardly/ scarcely ever| never • Certainty(+VB):certain(ly),undoubtedly, absolutely|probably,likely to(+INF)| possibly,perhaps,maybe| Uncertainly,unlikely to| certain(ly) not, definite(ly) not • Degree(+VB/Adj):very + ADJ. Significantly, substantially, dramatically, strongly, widely (used)mostly, greatly, highly, too, rather, fairly, quite slightly, hardly, scarcelyNew sitesforwindfarmsare likely to be mostly offshore Global carbon emissions have significantly increased in the last years

5. EXERCISE DEGREE A 1 We installed a complete new system We installed a completely new system 2 It was a really enjoyable film It was a real enjoyable film 3 The product is full guaranteed for a year The product is fully guaranteed for a year 4 The new car was a closely guarded secret The new car was a close guarded secret 5 He's a highly paid executive He's a high paid executive

6. EXERCISE DEGREE B • Plant and animal life can be greatly affected by global warming • He's a highlyqualified engineer • It was a badlywritten report and it needed a lot of corrections • He presented a wellstructured report • Supercharger engines achieve extremelyhigh performance • Lignite’s energy content is rather low • Wind power is likelyto be the most widelyused renewable energy source in the future • Stacked solar cells significantlyincrease the efficiency of solar cells • With a better control of CO2 emissions global warming would neverhave increased • Simply throwing trash into the recycling bin hardlydoes anything to reduce rubbish

7. TRANSLATION • Industrial and domestic pollutionHAVE/HAS RISEN/INCREASED IN THE LAST 50 YEARS. • Industrial air pollution includes the so-called “greenhouse gases”, LIKE/SUCH AS CARBON DIOXIDE and CFCs … . • BESIDES/IN ADDITION TO THESE GASES, we must not forget sulphur dioxide and nitrogen oxides, • WHICH RESULT IN/GIVE RISE TO ACID RAIN. • The largest single cause of industrial air pollution is the electricity industry, AS/SINCE ALL FOSSIL FUELS PRODUCE, AT LEAST, CARBON DIOXIDE. • NEW TECHNOLOGIES ARE BEING APPLIED in a few places in order to minimize the effect of dangerous gas emissions, • but these technologies are still very expensive and WOULD MAKE/CAUSE THE PRICE OF ELECTRICITY Ø/TO RISE/INCREASE .

8. TRANSLATION • Two important causes of water pollution are ACID RAIN AND THERMAL POLLUTION. • Land pollution is also an environmental THREAT • IT ALSO TAKES PLACE/HAPPENS/OCCURS WHEN THE INDUSTRIAL WASTE is buried or ….. • Usually, …but, AS WE HAVE SEEN, …, • and … UNLESS WE CONTRIBUTE to reduce global pollution AS MUCH AS WE CAN.

9. VIDEO: TYPES OF POLLUTIONAir pollution: 1:45-2:20 • Main causes: TOXIC GASES & EXHAUSTS THAT ARE LED OUT INTO THE AIR • Produced by: • INDUSTRIES • VOLCANOS • JET PLANES • AUTOMOBILES • FOTEST FIRES • BURNING OF GARBAGE • Consequences: CONTAIN MANY HARMFUL GASES THAT CAUSE • DISEASES IN HUMAN BEINGS • DESTRUCTION OF VEGETATION • DAMAGE TO THE STRUCTURES ON EARTH • CAN ALSO FORM ACID RAIN

10. VIDEO: TYPES OF POLLUTIONWater pollution: 2:20-2:55 • Main causes: EFFLUENTS LED INTO WATER BODIES FROM • INDUSTRIES • SEWAGE FROM TOWNS & CITIES • WASHING CLOTHES & CATTLE IN WATER BODIES • RESIDUES OF FERTILIZERS & PESTICIDES CARRIED INTO WATER BODIES DURING RAIN The list of pollutants can be quite long • OIL SPILL IN THE OCEANS HARMS MARINE LIFE

11. VIDEO: TYPES OF POLLUTIONLand pollution: 2:55-4:22 • Main sources: HEAPS OF SOLID WASTE FROM • HOUSES, CATTLE SHEDS, INDUSTRIES, AGRICULTURAL FIELDS • It includes: • HAZARDOUS WASTE • GLASS • FRUIT & VEGETABLE WASTE • DEAD BODIES OF ANIMALS • OLD CLOTHES, PAPER, PLASTIC BOTTLES, CANS • EXCRETA, CHEMICALS, WOOD PIECES • Consequences: • THE HEAPS OF SOLID WASTE PROVIDE BREEDING GROUND FOR GERMS • IN ADDITION TO SPOILING THE BEAUTY AND SURROUNDINGS THEY EMIT FOUL SMELL • Solutions: CONTROLLING LAND POLLUTION. WASTE DISPOSAL DONE CAREFULLY & SCIENTIFICALLY. IT DEPENDS ON THE KIND OF SOLID WASTE: • CONSTRUCTING MATERIAL IS BURIED IN LAND FILLS • PLASTIC, TIN CANS, METAL SCRAP, PAPER MUST BE RECYCLED • PLANT & HOUSEHOLD ORGANIC MATERIAL SHOULD BE TURNED INTO MANURE • BIOGAS CAN BE OBTAINED FROM BIODEGRADABLE WASTE • WASTE FROM HOSPITAL & NURSING HOMES SHOULD BE BURNT IN INCINERATORS

12. VIDEO: TYPES OF POLLUTION Soil pollution: 4:20-4:57 • Difference with air pollution: LOCALIZED PHENOMENON (AIR & WATER POLLUTION SPREADS TO LONG DISTANCES) • The two main reasons for soil pollution are: • POLLUTANTS WASHED DOWN FROM THE ATMOSPHERE BECAUSE OF RAIN • INSECTICIDES AND PESTICIDES APPLIED TO THE CROPS THIS ALTERS THE COMPOSITION AND QUALITY OF THE SOIL Noise pollution: 4:57-6:00 • What is noise?: ANY UNWANTED SOUND • Unit of measurement:DECIBEL (DB) • Examples: THE LOWEST SOUND = 1 db, A ROCKET TAKING OFF = 180 db. NORMAL TALK= 60db • Consequences: PRODUCE ADVERSE EFFECTS ON HUMAN BEINGS & OTHER ANIMAL LIFE • Which two aspects of noise are injurious for health? LOUDNESS and DURATION OF NOISE • Other consequences: ACUTE DAMAGE TO THE EAR DRUM, DEAFNESS, LOWERS EFFICIENCY OF WORK, DISTURBS SLEEP, IRRABILITY Thermal pollution: 6:00-6:25 • What is thermal pollution?: RELEASE OF HEATED GASES OR WATER REPEATEDLY INTO THE ENVIRONMENT, INCLUDING WATER BODIES • Consequences: • IF RELEASED IN THE ATMOSPHERE THEY WARM UP THE AIR IN THAT AREA • IF RELEASED IN WATER BODIES THEY KILL THE AQUATIC LIFE

13. LISTENING: GREENHOUSE EFFECT • A greenhouse is a building whose sides and roof are made of glass so that the temperature inside is magnified. And it is used to grow plants that need high temperatures. • These changes result from increasing the carbon dioxide levels in the atmosphere, thus raising the surface temperature of the earth. And this is known as the “Greenhouse Effect”. • since 1860, with a sharp increase since 1958. • The main reason is the burning of fossil fuels. • by about 15% -from about 290 to about 340 parts per million. • about 0.032%

14. LISTENING: GREENHOUSE EFFECT • incoming sunlight consists of many wavelengths, including some very dangerous ones. • But ozone, water vapour and CO2 destroy the harmful wavelengths. So what reaches the earth is visible light. It is absorbed and reradiated into the atmosphere as longer wavelength infrared (IR) radiation, or heat, as the earth cools. • This IR radiation is absorbed by CO2. • The CO2 then radiates a portion of the absorbed heat energy back to the earth, to warm the atmosphere. • Like the glass in a greenhouse, the CO2 in the atmosphere acts as a one-way filter that allows visible light to enter the Earth’s atmosphere, but prevents longer wavelength heat radiation from leaving. • Assuming that energy is arriving from the sun at a constant rate, then as the level of CO2 increases, the average surface temperature of the Earth should rise. • in 1863, but it was taken as a serious matter in 1956. • a projected increase in CO2 to 375 parts per million in the year 2000 could cause the average air temperature to increase by about 0.5ºC.

15. GRAPHS & FIGURES • As can be seen/ As shown INTHE TABLE/ GRAPH • As can be seen / As shown IN ØTable/Graph 2 • UP: RISE / INCREASE / GROW /CLIMB /GO UP • DOWN: DECREASE / DROP / FALL / DECLINE/ GO DOWN Typically N & Vb are modified by DEGREE ADJ/ADV ( e.g. a sharp increase / increased sharply) PREPOSITIONS: - Figures: BY(about)Ø 10% /FROM…(UP)TO Ø 10%/ACCOUNT FOR 10% • Time: OVER a period / FROM …TO /… DURING/… SINCE (1994)/ FOR a long time • With NOUNS : Rise / increase / growth / drop / change / decline / decrease + IN value

16. EXERCISE B: US Electricity • The two PIECHARTS ILLUSTRATE the production of electricity in the US BY SOURCE in 2003 and 2012. • In general, COAL was the most important …., although nuclear power GREW in importance. • In 2003, coal-powered stations were the main source of electricity, producing 46% of electricity, and this FIGURE increased TO 55% in 2012. • The SECOND most important source … was natural gas, with almost 25%. • However, by 2012, this had DECLINED to just 12.3%. • Hydroelectric power also declined OVER the same period, FROM 16% to less than 14%. • BY CONTRAST nuclear energy gained in importance. • It ROSE from just 1.4% of production in 2003 to almost 14% in 2012, a TEN FOLD increase. • IN SUMMARY more electricity was produced from coal and nuclear energy, WHILE natural gas, hydroelectric power, and oil declined IN IMPORTANCE

17. VIDEO: HOUSING PRICES • What is VERY SIGNIFICANT about in the four countries OVER THE DECADE is that the houses in Japan DECLINEDSHARPLYIN VALUE, FALLINGBY 40% • This CONTRASTSVERY STRONGLY with Australia. • The latter did see A MARGINAL DROPIN house prices FROM2000 TO2002 • but the next two years experienced VERY STRONG GROWTH. • After A STABLE PERIOD LASTING four years Australian house prices DOUBLEDIN VALUE … • … so that OVERTHE WHOLE PERIOD house prices in Australia RECORDEDGROWTHOF 120%

18. VIDEO: HOUSING PRICES • SIMILARLY, the UK saw A CONSIDERABLE INCREASE • From2000TO 2008 house prices MORE THAN DOUBLED … • … but after that FELLSHARPLY • Canada also stands IN SHARP CONTRAST … • …because it is the only country where HOUSE PRICE GROWTHWASREGULAR

19. VIDEO: HOUSING PRICES • The table data shows that THE 120% CHANGE INHOUSE PRICES in Australia …. • … was FROMA QUARTER OF A MILLION DOLLARS TOMORE THAN HALF A MILLION DOLLARS • However AVERAGEANNUAL WAGES during that period ONLYINCREASEDBY ABOUT 50% • The effect of this is that in 2000 HOUSE PRICES EQUATEDTO 570% … • while ten years later THAT FIGURE HAD CLIMBED CONSIDERABLYTO 780%

20. VIDEOACID RAIN PARAGRAPH 1 • Which is the common thing in some lakes of Europe? • What is happening to some forests in Central Europe? • Which percentage of forests is affected? • What is happening to the future of salmon and trout fishing in N & Sw? • How many lakes in Sweden are not capable of supporting fish? • Which is the cause? PARAGRAPH 2 • Which substances contain sulphur? • When does this sulphur become sulphuric acid? • What happens to this sulphuric acid • Which are the consequences of it falling locally? • what happens to pollution produced in Britain? PARAGRAPH 3 • What effects does it have? • For example in Scandinavia the fish were disappearing from the lakes why?. • That is, what?

21. VIDEOACID RAIN PARAGRAPH 1 • they are threatened by a huge ecological disaster • the great forests are now dead or dying • 30% • the future of salmon and trout fishing is threatened • More than 4,000 • acid rain PARAGRAPH 2 • All fossil fuels, that is coal, oil and gas contain sulphur • when these are burnt, such as in power stations or motor vehicles • This sulphuric acid goes up into the air with the exhaust fumes and sooner or later it must fall back to earth • people who live in, near power stations notice that their cars rust quickly or that their masonry gets worn away • It is transported as far as Scandinavia PARAGRAPH 3 • it damages vehicles and buildings, but it also has serious ecological effects • this was due to the acidification of the lakes, • there was so much sulphuric acid in the rain that the lakes themselves became acid which killed the fish

22. VIDEOACID RAIN PARAGRAPH 4 • Apart from the fish, what other things does it affect? • In Czechoslovakia what happened in the 60’s ? • When was the phenomenon noticed in Germany? • What is the situation now? • Which is the main source of acid rain? • What is required in Japan and W Germany? • What do these mechanism do? • What is the solution in Britain? • Is that any real use? PARAGRAPH 5 • Which fuel could make some difference? • What is another major source of acid rain? • What is possible with this type of fuel? • What do these mechanisms do? • When is this solution not possible? • Why? PARAGRAPH 6 • Summarize this paragraph

23. VIDEOACID RAIN PARAGRAPH 4 • Acid rain also affects trees • In Czechoslovakia in the 60’s trees began to die and now there are large areas of former forest which consist of only dead trees • in the late 70s • many forest areas are dying and some are already dead • electric power stations • laws requiring their power stations to build filter installations • prevent the acid getting out into the air • that the chimneys be built taller so that the pollution is more distributed • it improves our air in our cities but it distributes the pollution further afield, so that forests in Scandinavia get affected PARAGRAPH 5 • the introduction of lead-free petrol • motor vehicles • it would be possible to build exhaust filters • prevent the release of acid • with lead in the petrol • because it prevents the filter mechanism from working PARAGRAPH 6 • some of the forests are already too badly affected to be saved, but there are a lot more forests which are slightly affected, and if action was taken now, then they perhaps could be saved. • Our forests and lakes are more than just places for relaxation and leisure. They are an essential part of the ecological balance which keeps our planet alive. If the problem is not faced very soon, it may be too late

24. UNIT 10 Vocabulary • Wastedisposal • Recycling Grammar and functions • Describingprocesses: Sequencing • Revision of the grammar structures

25. LISTENING: WASTE DISPOSAL • Which are the 4 main sources of waste? MINES (39%), AGRICULTURE (53%), INDUSTRY (2%), DOMESTIC HOMES / WASTE (6%) • Where does it go? • OPEN DUMPS (55%) • NOT COLLECTED OR DISPOSED OF (23%) LEFT ON THE SPOT • LAND-FILL METHOD (12%) BURIED IN THE GROUND • BURNT (9%) • DUMPED TO SEE (1%) DOMESTIC WASTE (RUBBISH, GARBAGE) • Open dumps: advantages : EASY TO OPERATE and THE CHEAPEST OF THE 3 • disadvantages: unsightly, CAUSE AIR POLLUTION WHEN RUBBISH IS BURNT, SMELL, MATERIALS & LAND ARE WASTED and they can contaminate ... • Land fill : advantages: CHEAP, NO OBJECTABLE SMELLS OR PESTS, and when the landfill is completed LAND MORE USEFUL THAN BEFORE (e.g. sports field or park) Disadvantages : WASTE MATERIALS and USES A LARGE AREA OF LAND …. • Incineration (i.e. BURNING) Advantages: …about 80% OF DOMESTIC RUBBISH and REDUCE ITS VOLUME BY 90%; it requires VERY LITTLE LAND and it produces INCOME FROM THE RECOVERY OF WASTE METAL & GLASS Disadvantages: EXPENSIVE TO BUILD AN INCINERATION PLANT and CAUSES AIR POLLUTION unless sophisticated pollution controls are installed.

26. TRANSLATION: RESOURCE RECOVERY • Numerous thermal processes recover energy IN DIFFERENT WAYS FROM SOLID WASTE. • THESE SYSTEMS/METHODS ARE DIVIDED INTO TWO GROUPS: combustion processes and pyrolysis processes. • A number of companies burn in-plant wastes in conventional incinerators INORDER TO PRODUCE/GENERATE STEAM; • THE WATER FLOWING through the tubes ALLOWS THE HEAT GENERATED IN THE COMBUSTION CHAMBER TO BE ABSORBED AND GENERATE STEAM. • Pyrolysis CONSISTS OF DECOMPOSING CHEMICALLY SOLID WASTE by heat in an oxygen-reduced atmosphere. • THIS RESULTS IN A GAS THAT CONTAINS various gases, DEPENDING ON THE ORGANIC CHARACTERISTICS OF THE LYROLIZED MATERIAL • IF USERS SEPARATED THEIR RUBBISH A LARGER AMOUNT OF WASTE COULD BE RECYCLEDand that would improve life in our planet • … since THE GREATER THE RECYCLED VOLUME ,THE LONGER OUR NATURAL RESOURCES WILL LAST

27. VIDEO-STORY OF ALUMINIUM RECYCLING • Which are the properties of Al? LIGHT & DURABLE • What kind of metal s it? NON-FERROUS METAL • It is normally used for? DRINK CANS • How much was recycled in Devon last year? 660 tonnes of Al cans • Which other material is also collected? STEEL • How? On kerbside BINS, BOXES, BAGS, RECYCLING BANKS

28. VIDEO-STORY OF ALUMINIUM RECYCLING • AFTER THE CANS HAVE BEEN COLLECTED, THEY ARE TAKEN TO A RECYCLING DEPOT (b) • IN ORDER TO SEPARATE STEEL CANS FROM ALUMNIUM, A GIANT MAGNET IS USED TO REMOVE STEEL (e) • ALUMNIUM ISTHENCRUSHED AND BALED (c) • THE ALUMNIUM ISTHENSENT TO A REPROCESSING COMPANY (h) • ONCE IT ARRIVES IT IS SHREDDED INTO BITS THE SIZE OF A TEN-PENCE PIECE (g) • THE SHREDS ARETHENPASSEDTHROUGH A DOUBLE MAGNETIC DRUM SEPARATOR TO REMOVE STEEL CONTAMINATES THAT MAY HAVE BEEN MISSED (k) • BEFORE THE CANS CAN BE MELTED, THEY NEED TO BE DE-COATED OF THE VARNISH LACQUER WHICH IS USED DURING MANUFACTURING TO PROTECT THE CANS (d) • THIS IS REMOVED BY BLOWING HOT AIR THROUGH THE SHREDS (l) • THE HOT, DE-COATED CANS CAN THENBE FED INTO A HUGE 90 TONNE FURNACE TOBE MELTED (i) • NEXT THE MOLTEN METAL IS CAST INTO INGOTS. THIS IS ACHIEVED BY TILTING THE FURNACE AND POURING THE MOLTEN METAL INTO A CASTING UNIT (f) • AFTER BEING CAST AND CHILLED, THE ALUMNIUM INGOTS ARE CUT SQUARE AND SENT OFF TO THE MILL, WHERE THEY ARE ROLLED OUT INTO SHEETS (a) • THE SHEET ALUMINIUM ISTHENSOLD ONTO MANUFACTURERS FOR A RANGE OF USES (j)

29. VIDEO-STORY OF ALUMINIUM RECYCLING i-The cans are collected and taken to a recycling depot A- A magnet is used to separate the steel cans from aluminium F- Next aluminium is crushed and baled C- After this the aluminium is sent to a reprocessing company E- Here the aluminum is cut down into very small pieces B- A magnetic drum is used to remove any rests of steel K- The varnish coat that protected the can is removed before melting L- This is done by blowing hot air G- Once the cans have been decoated, they are taken to a furnace H- Subsequently, the liquid aluminum is poured into casts J- The square ingots are then rolled into sheets D- And these aluminium sheets are used to manufacture new products USES: Car parts (wheels), bikes, packaging (foil, cans), construction parts, household appliances

30. VIDEO-STORY OF ALUMINIUM RECYCLING • Which are the characteristics of Aluminium? LIGHT, DURABLE, THE MOST WIDELY USED NON FERROUS METAL • How much was recycled in Devon last year? 660 TONNES OF ALUMNIUM CANS • Where is Aluminium collected from? KERBSIDE BINS, BOXES, BAGS, RECYCLING BANKS EXPLAIN THE STEPS OF ALUMNIUM RECYCLING • AFTER THE CANS HAVE BEEN COLLECTED, THEY ARE TAKEN TO A RECYCLING DEPOT • IN ORDER TO SEPARATE STEEL CANS FROM ALUMNIUM, A GIANT MAGNET IS USED TO REMOVE STEEL • ALUMNIUM IS THEN CRUSHED AND BALED • THE ALUMNIUM IS THEN SENT TO A REPROCESSING COMPANY • IT IS SHREDDED INTO BITS THE SIZE OF A TEN-PENCE PIECE • THE SHREDS ARE PASSED THROUGH A DOUBLE MAGNETIC DRUM SEPARATOR TO REMOVE STEEL CONTAMINATES THAT MAY HAVE BEEN MISSED

31. VIDEO-STORY OF ALUMINIUM RECYCLING • BEFORE THE CANS CAN BE MELTED, THEY NEED TO BE DE-COATED OF THE VARNISH LACQUER WHICH IS USED DURING MANUFACTURING TO PROTECT THE CANS • THIS IS REMVED BY BLOWING HOT AIR THROUGH THE SHREDS • THE HOT, DE-COATED CANS CAN THEN BE FED INT A HUGE 90 TONNE FURNACE TO BE MELTED • NEXT THE MOLTEN METAL IS CAST INTO INGOTS. THIS IS ACHIEVED BY TILTING THE FURNACE AND POURING THE MOLTEN METAL INTO A CASTING UNIT • AFTER BEING CAST AND CHILLED, THE ALUMNIUM INGOTS ARE CUT SQUARE AND SENT OFF TO THE MILL, WHERE THEY ARE ROLLED OUT INTO SHEETS • THE SHEET ALUMINIUM IS SOLD ONTO MANUFACTURERS FOR A RANGE OF USES Give examples of use of recycled aluminium • CAR PARTS, SUCH AS ALLOY WHEELS, BIKES, PACKAGING (eg FOIL & CANS), CONSTRUCTION PARTS, HOUSEHOLD APPLIANCES

32. ALUMINIUM RECYCLING- REORDER 1 Aluminum cans are gathered from recycling centers 6 They are sent to a scrap processing company where they are collected into large bales. 3 The bales are then sent to an aluminum company where the cans are shredded, crushed, stripped and burned 7 They are then sent into a furnace where they are melted with new, untouched aluminum and the two are melted together. 5 The new aluminum is then poured out into sheets, and cut down into sheets 1/100th of an inch thick. 2 The aluminum then cools, and is coiled up into large rolls and sent to can makers. 4 The can makers then mold the aluminum into can shapes, and send them off to soda makers to bottle their beverage.

33. Sample exam: MULTIPLE CHOICE • Electromagnetism led to the development of electric motors • As opposed to engines, motors need electricity to work • Generators can produce as much energy as 1.5 million volts • The addition of chromium prevents iron from corroding • Variation in the field around a conductor may be produced by varying the strength of the field • The conductor in which an emf is induced should be part of a circuit • Conductors let electricity flow through them • If a compass is left near an electric current, its needle will be deflected • What would happen if you heated this bar? • A piece of iron is magnetised when it is placed near a current