Exercises

1. Answer the questions:

1. What is a capacitor used for? 2. What are the main parts of a capacitor? 3. What is the function of insulators? 4. What does the capacity of a capacitor depend on? 5. What is the difference between a fixed capacitor and a variable one? 6. What should be done in order to change the capacity of a capacitor? 7. What is the relation between the value of capacity and the distance of plates? 8. What type of insulators have variable capacitors? 9. What should be done in case a capacitor has a trouble?

2. Find the correct variant. Remember it:

1. a capacitor is used

a) to supply voltage

b) to increase the voltage output

c) to store energy

2. the main parts of a capacitor are

a) insulators only

b) metal plates only

c) metal plates and insulators between them

3. the function of insulators is

a) to store energy

b) to isolate the metal plates

c) to prevent a short between the metal plates

4. the capacity of a capacitor depends on

a) the size of the plates

b) the distance between the plates

c) the material of the insulators

5. the capacity of a fixed capacitor

a) is constant

b) is varied

6. the plates of a variable capacitor

a) can be moved

b) cannot be moved

8. Energy Supply

Word List

issue amount sustainable approach renewable reduced consumption environmental consequence to cause to disrupt a threat

[΄isju:] [ə΄maunt] [səst΄einəbl] [ə΄prout∫] [ri΄nju:əbl] [ri΄dju:st] [kən΄sΛmp∫ən] [invaiərən΄məntəl] [΄kənsikwəns] [΄ko:z] [dis΄rΛpt] [΄θret]

проблема кількість ті, що лежать в основі підхід відновний зменшений споживання оточуюче середовище наслідок визивати руйнувати погроза

Exercise 1. Find antonyms:

to disrupt rapidly death to reduce developed health

slowly life to increase to create illness developing

Exercise 2. Find the equivalents:

energy supply improved technology reduced consumption to cause changes environmental threat standard of living the global warming nuclear energy

поліпшена технологія визивати зміни погроза навкол. середовищу рівень життя зменшене споживання постачання енергії ядерна енергія глобальне потепління

Read the text

Energy supply

The issue of energy has two main aspects: type of energy used and amount of energy used. Sustainable approaches to energy supply are based on nuclear, renewable energy sources and more effective use of energy, through either improved technology or reduced energy consumption.

The environmental consequences of today’s energy policies are potentially catastrophic. The global warming caused by burning fossil fuels will disrupt thousand of kilometers of heavily populated and productive tropical coastline, as well as causing major changes in agro ecological zones in both temperate and tropical areas. Ecologists are concerned that natural ecosystems will not be able to adapt rapidly enough to these changes through migration of plant and animal species, since the climate has not changed this rapidly previously. The ability of human societies to adapt to these changes is an open question.

The burning of fossil fuels also causes acid rain, contributing to the death of large areas of forest in Europe. Toxic heavy metals originating from fossil fuels or released under acid soil conditions (primary cadmium, zinc and lead) are also found in disturbingly high concentrations in soils and vegetation in many places in Europe. The risk associated with nuclear energy is also great, as illustrated by the Chernobyl accident. It would be ironic if, in our efforts to reduce acid rain and the greenhouse effect, we shifted to nuclear power, which may pose an even greater environmental threat.

The answer lies partly in development of renewable energy sources such as biomass, methane, sun, wind, waterfall and wave power. The other part of the solution lies in using less energy and getting more out of each unit of energy (increased energy efficiency).

In order to stabilize the CO₂ concentration in the atmosphere, CO₂ production must be reduced by 60-70 per cent in the developed countries. Through improved energy efficiency, choice of energy source and new technology some of this reduction can be achieved. The rest will have to be achieved by cutting down unnecessary consumption and a reduction in standard of living measured in terms of material consumption. However, quality of life need not necessarily be reduced—in fact; it may increase because of better physical and mental health.

Exercise 3. Answer the following questions:

1. What are approaches to energy supply based on?

2. Why are environmental consequences of today’s energy policies catastrophic?

3. What does burning of fossil fuel cause?

4. How can the problem of reduced energy consumption be solved?