Test . Atmospheric Electricity

Grammar material: : The Present Perfect/Past Simple Tense

Text “Atmospheric electricity”.

Electricity plays such an important part in modern life that in order to get it, men have been burning millions of coal. Coal is burned instead of its being mainly used as a source of valuable chemical substances which it contains. Therefore, finding new sources of electric energy is a most important problem that scientists and engineers try to solve. In this connection one might ask: "Is it possible to develop methods of harnessing lightning?" In other words, could atmospheric electricity be transformed into useful energy?

Indeed, hundreds of millions of volts are required for a lightning spark about one and a half kilometre long. However, this does not represent very much energy because of intervals between single thunderstorms. As for the power spent in producing lightning flashes all over the world, it is only about 1/10,000 of the power got by mankind from the sun, both in the form of light and that of heat. Thus, the source in question may interest only the scientists of the future.

It has already been mentioned that atmospheric electricity is the earliest manifestation of electricity known to man. However, nobody understood that phenomenon and its properties until Benjamin Franklin made his kite experiment. On studying the Leyden jar (for long years the only known condenser), Franklin began thinking that lightning was a strong spark of electricity. He began experimenting in order to draw electricity from the clouds to the earth. The story about his famous kite is known all over the world.

On a stormy day Franklin and his son went into the country taking with them some necessary things such as: a kite with a long string, a key and so on. The key was connected to the lower end of the string. "If lightning is the same as electricity," Franklin thought, "then some of its sparks must come down the kite string to the key." Soon the kite was flying high among the clouds where lightning flashed. However, the kite having been raised, some time passed before there was any proof of its being electrified. Then the rain fell and wetted the string. The wet string conducted the electricity from the clouds down the string to the key. Franklin and his son both saw electric sparks which grew bigger and stronger. Thus, it was proved that lightning is a discharge of electricity like that got from the batteries of Leyden jars. Trying to develop a method of protecting buildings during thunderstorms, Franklin continued studying that problem and invented the lightning conductor. He wrote necessary instructions for the installation of his invention, the principle of his lightning conductor being in use until plow. Thus, protecting buildings from strokes of lightning was the first discovery in the field of electricity employed for the good of mankind.

Test . Atmospheric Electricity

I. Fill in the blanks with the words from the box:

Protect, electrified, connected, because of, power, instead of, substances, valuable, developed, burn

1. Uranium is dangerous …its radioactivity.

2. We … coal to get energy.

3. My work is … with semiconductors.

4. Franklin … a new theory of electricity.

5. These objects are … .

6. What fuel can be used … coal?

7. The reactor supplies …to the turbine.

8. Many chemical … can be produced from coal.

9. Coal is the source of … substances.

10. We must …our nature.

II. Match the word combinations:

important jar

modern electricity

chemical power-plant

atmospheric part

earliest buildings

Leyden manifestation

protect life

nuclear substances

III. Find the end of the sentences:

1.Benjamin Franklin… 1. -was connected to the lower end of the string.

2. Nobody… 2. - invented the lightning conductor.

3. The story… 3. - understood that phenomenon.

4. The key… 4. - of the kite was known all over the world.

5. Franklin… 5. - made his kite experiment.

Date: 2016-04-22; view: 1463