English Unlimited HTL 3, Schulbuch mit Audio-CD und CD-ROM

39 Success 03 LANGUAGE SKILLS EXPLORE LOOK AGAIN EXTRAS Read the paragraphs about electricity generation and measurement. Parts of the text are missing. Choose the correct sentence parts to complete the text. There are two extra parts that you should not use. a 50 How is electricity generated? A generator is a device that converts mechanical energy into electrical energy. In 1831, Michael Faraday discovered that when a magnet is moved inside a coil of wire, (1) . ‰is relationship between electricity and magnetism is what makes generators work. A generator uses magnets and coils of wire, (2) . ‰e rotor usually is a rotating sha¢ with coils or magnets attached. On a wind turbine, the rotating blades are attached to a drive sha¢ (3) . ‰e same principle applies to any form of generator, (4) : steam in thermal power plants, combustion gases in gas-red power plants or water in hydropower plants. How is electricity measured? Electricity is measured in units of power called ‘watts’. ‰e name is derived from James Watt, a Scottish scientist. A kilowatt represents 1,000 watts. A kilowatthour (kWh) equals the energy of 1,000 watts (5) . Other important units of measurement are volts and amps, used to measure electric potential and electric current. Read more about volts and amps, and about the scientists Alessandro Volta and André-Marie Ampère on the internet. a which spins inside the generator b forming the rotor (the rotating part) or the stator (the fixed part) of a generator c which always turns anticlockwise d only the driving force is different e electric current flows in the wire f blades that turn g working for one hour Label the cross-section of a wind turbine in 50a with words from the box. There are two extra words you should not use. b Listen to Mark talking about energy production and answer the questions using a maximum of four words. 1 What field is Mark’s company working in? 2 How many people work for Mark’s company? 3 What do you need to generate energy from wind? 4 What do solar power plants need to be efficient? 5 Why is geothermal energy expensive? 6 What were hydropower plants called previously? 7 Where will this interview be printed? 8 Where should you mention the interview? 51 TCD 1/19 blades combustion chamber drive shaft generator voltage Nur zu Prüfzwecken – Eigentum des Verlags öbv