Task1: Study this statement: “Twenty billion batteries are sold every year.” Why you think this is so? What different kinds of batteries are there? list some of the things you use which contain batteries Compare your list with someone else's Answers: I think it is so, because in the world, millions of electric devices which contain batteries have been used They can be computer mice, remote controls, cell phones, torches, etc…Each of these devices has its own kind of baterry For example, a cell phone has a small thin battery in the shape of square or rectangle while a torch often has a bigger battery Task2: Try to complete this table of the differences between two kinds of cells Use these tems: secondary zinc manganese dioxide portable phones Zinc-carbon cell cadmium torches primary NiCad cell Type of cell Positive electrode primary manganese dioxide Negative electrode Example of use Type of cell Positive electrode Task 4: secondary Negativeelectrode EMF Example of use nickel zinc cadmium torches Zinc-carbon cell a manganese dioxide A zinc ISV and the internal resistance about O.SQ in torches NiCad cell nickel cadmium 1.2V and is made in the same sizes as primary cells HP2, PP3; button types are also available portable phones Task 6: f It’s called a transformer iron core It’s protecs a circuit d It’s called a milliampe meter It measures very small currents c It’s called a resistor.it adds resistance to a circuit a: It’s called a adjustable capacitor It varies capacitance in a circuit g:It’s called a potentiometers It varies the current in ciircuit j : It’s called a voltmeter It measures voltages 10 i : 4e: b: Task Each ofthese verbs has a related noun ending in -er or -or which refers to an instrument or component Complete the column of nouns You have met these nouns in this and earlier units oscillate transmit oscillator transmitter transform transformer charge charger 5.rectify rectifier process processer amplify amplifier collect collectter detect detecter 10 tune tuner task 10.Match each component or unit with its function in a battery charger 1-a 2-h 3-d 4-f 5-g 6-c 7-g 8-e Task 11describe the block diagram of the battery charger and the function of each building block Your description should answer these questions: 1.battery charger function ac line changes into line with lower voltage dc