Упр .8. Вставьте нужное слово .

1. either; 2. either... or; 3. neither; 4. neither... nor

1. Energy can... be created... destroyed.

2. Matter can exist in... of three states: solid, liquid or gaseous.

3. When we rub two surfaces together, we do work, yet... of the bodies is given a kinetic energy,

4. There are two common ways to connect cells... in parallel... in series.

 

Упр. 9. Переведите на русский язык. Назовите время и залог.

1. Half of the power generated by the Kuibyshev hydroelectric station is transmitted by long-distance power line to Moscow.

2. Intensive research is being carried on in the field of electronics.

3. In our country many power plants have been put into operation in the course of the last 10 years.

4. This instrument may be used both for a direct current and for an alternating current.

 5. The basic circuit of the instrument was described in detail in the last article.

Упр. 10. Переведите на английский.

1. Дом строится. 2. Рабочие строят дом, 3. Студенты используют этот прибор. 4. Этот прибор используется в работе. 5. Ему помогут. 6. Он поможет.

Упр. 11. Поставьте вопросы к подчеркнутым словам.

1. Electricity plays an important part in our everyday life.

2. In the middle of the last century Maxwell worked out a theory of electromagnetism.

3. In our experiment the rubber rod has attracted the ball.

4. The first atomic power station was built in the USSR in 1954.

5. The explanation of magnetism will be given in the next lesson.

 

Lesson 4.

Text.

The Induction Coil

The induction coil is known to consist of two coils wound together but connected separately. The simplest induction coil is illustrated in Fig. 6. One coil is wound about a core with its ends connected in series.

On the outside of the first coil la wound a second coil of fine wire with its ends connected to two carbon rods. We know the inside coil lo be called the primary coil. The outside coil of small wire is called the secondary coil.

One should remember the number of turns on an induction coil determines the change in voltage. For example, an induction coil with a good core has a hundred turns of wire on the primary coil and is connected with a battery. The secondary coil has a thousand turns, or ten times as many turns as on the primary. A six-volt battery forces the electricity through the primary circuit. The secondary coil having ten times as many turns of wire as the primary coil, has approximately ten times many volts, or sixty volts. Anyone who touches both terminals of the secondary coil will receive a shock.

 

People are known to differ in their "ability" to be shocked by a current of electricity. The nerves and the heart are affected by shock. A shock, which might be fatal to some people, would hardly be felt by others. Also, the electricity in attempting to flow through the body, needs a good connection. Since water is known to conduct electricity, a person may get a severe shock if he is standing on a damp floor or if his hands are wet when in contact with an electric appliance.

The strength of an induction coil proved to depend upon the size of wires used, the number of turns of wire in each coil and the current used. We also consider the strength of an induction coil to depend upon the workmanship of the person making the coil.

Words and word combinations:

induction coil – индукционная катушка

separately - отдельно

wind (wound) – наматывать, обматывать

core – сердечник

turn –виток

approximately – приблизительно

severe – серьезный

strength –сила

to affect –воздействовать

damp –сырой

workmanship – квалификация, мастерство

 

Assignment:

I. Find in the text the following words and word combinations:

Простейший, наружная катушка, тысяча витков, проводит электрический ток, может получить шок, зависит от мастерства (квалификации), сила индукционной катушки, первичная катушка, способность, тонкий провод, прикасаться к обоим зажимам, серьезный шок.

II. Answer the questions.

1. What does a simple induction coil consist of

2. How do we call the inside coil?

3. How do we coil the coil wound on the outside of the first coil?

4. What will happen if you touch both terminals of flu- secondary coil?

5. Do people differ in their "ability" to be shocked by a current of electricity?

6. May a person gel a severe shock if he is standing on a damp floor?

7. Is it dangerous for a person if his hands arc wet when he is in contact with an electrical appliance?

8. What does the strength of an induction coil depend upon?