Work in pairs. Put questions to your partner and he (she) will answer them.

1. if it is possible to see a single drop of water in the sea. 2. if the steam-generator of the nuclear reactor contains water.3. if man has learned to split atoms. 4. if atomic power finds new application in industry. 5. if our country constructed the first in the world nuclear power plant.

6. Arrange the words given in Columns 1 and II in pairs of antonyms:

I                                 II

possible                 past

useful                    impossible

to construct           to find

present                  useless

largest                   limited

unlimited               smallest

to increase             to destroy

to lose                   to decrease

7. Fill in the blanks with prepositions:

I. Electricity plays an important part... our everyday life. 2. It is difficult to imagine now how people could do... electricity. 3. As my friend lives near the institute he usually goes there... foot. 4. I often go... bed late... night. 5. One form... power can be changed... another form. 6. Only a little part... solar power is used directly... present.

8. Translate the following sentences paying attention to the words need and turn:

1. Modern civilization needs more and more electricity. 2.You needn't go to the laboratory today. 3. The power needs in industry are increasing day by day. 4. People needn't use kerosine lamps today. 5. What do we need electric power for? 6. The Earth turns round the Sun. 7. Cold turns water into ice. 8. The Sun in its turn turns ice into water. 9. The turbines are turned by steam, gas and water. 10. In their turn turbines turn generators. 11. The teacher says: "It is your turn to read." 12. When you enter a dark room, turn the light on, and leaving it turn the light off. 13. It is possible to turn solar power into electric power owing to semicon­ductors.

9. Put all possible questions to the following sentences:

1. Useful power can be got from a nuclear reactor.       

2. The first nuclear power station was constructed in our country in 1954.  

Define the following words according to the model given below.

Model: The motor is a device transforming electric power into mechanical power.

power, battery, kinetic power, nuclear reactor, potential power

11.     Speak on:

1. The operation of a nuclear reactor.

2. The first industrial nuclear power station. 

3. The peaceful uses of atomic power.

12. Retell the text.

LESSON FOUR

MAGNETISM

In studying the electric current, we observe the following relation between magnetism and the electric current: on the one hand magnetism is produced by a current and on the other hand the current is produced from magnetism.

The earliest practical application of magnetism was con­nected with the use of a simple compass consisting of one small magnet pointing north and south.

A great step forward in the scientific study of magnetism was made by Gilbert, the well-known English physicist (1540-1603). He carried out various important experiments on electricity and magnetism and wrote a book where he put together all that was known about magnetism. He proved that the earth itself was a great magnet.

Reference must be made here to Galileo, the famous Italian astronomer, physicist and mathematician. He took great interest in Gilbert's achievements and also studied the prop­erties of magnetic materials. He experimented with them trying to increase their attracting power. One of his magnets, for example, could lift objects weighing 25 times its own weight.

At present, we are quite familiar with the fact that in magnetic materials, such as iron and steel, the molecules themselves are minute magnets, each of them hav­ing a north pole and a south pole. These molecules usually arrange themselves in a disorderly way, their north and south poles pointing in all directions and neutralizing one another.

The process of magnetization consists of turning these little magnets until all their north poles point in one direction and south poles in the other.

When iron and steel are magnetized, the molecules arrange themselves in a new orderly way instead of the disarrangement in which they neutralize each other. Dividing a bar magnet into two parts, one finds that each of the two parts is a magnet having both a north pole and a south pole. In other words, we obtain two smaller magnets instead of our having a single one of a larger size. Dividing one of these two smaller magnets into two will give us the same result. Thus, we could continue this process, always get­ting similar results.

On placing an unmagnetized iron bar near a strong magnet, we mag­netize it. Rubbing the magnet is not required for that process. In other words, our iron bar has been magnetized by the strong magnet without rubbing it.

 Exercises