According to the models given below form sentences combining suitable parts of the sentence given in Columns I, II, III, IV,

Models: (a) The current is known to consist of moving electrons.

(b) We know lightning to be a discharge of electricity.

4. Translate the following sentences using the infinitive:

1. Чтобы быть хорошим инженером, необходимо много читать и учиться. 2. Пирометр используется для измерения температуры горячих металлов. 3. Человек научился рас­щеплять атомы для того, чтобы получить большое коли­чество энергии. 4. Ученые пытаются решить проблему, связанную с новыми явлениями электричества. 5. Громо­отвод — это металлическое приспособление для защиты зданий от молнии. 6. Проводить опыты с атмосферным элек­тричеством было очень опасно в то время. 7. Намагнитить предмет — это значит поместить его в поле магнита.

5. Work in pairs, ask your fellow-students the following questions:

1. if electricity is a form of power.

2. if there are two types of electricity.

3. if alternating voltage can be increased and decreased.

4. if Franklin made an important contribution to the science of electricity.

5. if Ampere determined the difference between the cur­rent and the static charges.

6. if the electric current can flow through liquids and through gases.

7. if the electrolytes change greatly when the current passes through them.

8. if a negatively charged electron will move to the pos­itive end of the wire.

6. Form six sentences combining suitable parts of the sentence given in Columns I and II:

I II

1.The electric current is 1. the power of position.

2. Kinetic power is 2. electricity at rest.

3. Static electricity is 3. the flow of moving electrons.

4. Potential power is 4. the power of motion.

5. The direct current is 5. a discharge of electricity.

6. Lightning is 6. the flow of electrons in one

direction.

7. Explain why:

1. static electricity cannot be used to light lamps, to boil water, to run electric trains and so on.

2. voltage is increased and decreased.

3. the unit of electric pressure is called the Volt.

4. students must learn English.

5. the flow of moving electrons is a form of the electric current.

6. Ampere was wrong as to the current direction.

7. the current is said to flow from the positive end of the wire to the negative end.

8. Define the meaning of the following words:

battery, alternating current, direct current, static elec­tricity, electric current, wire, laboratory, terminal, electron

9. The following statements are not true to the fact. Correct them:

1. Electrons flow from the positively charged terminal of the battery to the negatively charged terminal. 2. Ampere supposed the current to flow from the negative pole to the positive. 3. Static electricity is used for practical purposes. 4. Static electricity is not very high in voltage and it is easy to control it. 5. To show that the charges are unlike and opposite Franklin decided to call the charge on the rub­ber positive and that on the glass negative. 6. Galvani thought that electricity was generated because of the contact of the two dissimilar metals used. 7. Volta took great interest in atmospheric electricity and began to carry on similar exper­iments. 8. The direct current is known to flow first in one direction and then in the opposite one. 9. The direct current is used for power and lighting purposes is assumed to go through 50 cycles a second.