4. Вставьте вместо пропусков местоимения some, any или no и переведите предложения на русский язык.

1. You may come at … time that is convenient to you. 2. Will there be … concerts at the club next month? 3. … trees remain green all the year round. 4. I have …time to help you. 5. Can I have … milk in my tea? I don’t like it black.

5. Перепишите следующие предложения: подчеркните причастие I и причастие II и установите функцию каждого из них, т.е. укажите, является ли оно определением, обстоятельством или частью глагола-сказуемого. Переведите предложения на русский язык.

1. Natural rubber is а thermoplastic material that becomes soft when heated and hard when cooled.

2. Matter composed of any сhеmiсаl combination of elements is called а compound.

3. Тhе smallest particle having all the characteristics of an elements is called an atom.

4. While bombarding the upper layers of the atmosphere, cosmic rays reach the surface of the earth. .

6. Переведите текст, пользуясь словарём. Текст перепишите.

Inductance and Mutual Inductance

Any conductor has some definite value of inductance. The induc­tance of a conductor shows how well it can provide induced voltage.

Elements of a circuit with a definite value of inductance are coils of wire called inductors. The inductance of a coil depends upon its size and material. The greater the number of turns of a coil, the higher is its inductance. An iron core also increases the value of inductance. Coils of this type are used for low-frequency currents while coils with an air core are used for high-frequency currents.

Two coils A and В are brought close together and a source of vary­ing current is applied to coil A. If a measuring device is connected across the terminals of coil В it will be found that a voltage is induced in this coil though the two coils do not touch. The secondary voltage, that is the voltage in coil B, is called induced voltage and energy from one coil to the other transfers by induction. The coil across which the current is applied is called the primary; that in which voltage is induced is called the secondary. The primary and the secondary coils have mutual inductance. Mutual inductance is measured in the same units as inductance, that is in henries.

Thus, when a rate of change of one ampere per second in the primary coil will produce one volt in the secondary coil, the two coils have one henry of mutual inductance.

It should be taken into consideration that induction by a varying current results from the change in current not in the current value. The faster the current changes, the higher the induced voltage.

7. Ответьте на вопросы к тексту.

1. What are elements with a definite value of inductance called?

2. What does the inductance of a coil depend upon?

3. How does the inductance of a coil depend upon the material of its core?

4. In what units is the value of mutual inductance measured?

5. What does induction by a varying current result from?

6. What is the relation between the current changes and the value of in­duced voltage?

7. For what type of current is an air core used?

8. What is the relation between the number of turns of a coil and its inductance value?

8. Вместо точек вставьте артикль, где это необходимо и переведите предложения на русский язык.

1. There is … telephone in the room. 2. … Baikal is … deepest of all the lakes in the world. 3. He has won … thousand roubles. 4. … poor in New York live in slums. 5. … courage was his main quality.

9. Перепишите предложения, подчеркните в них отглагольное существительное и переведите предложения на русский язык.

1. Many metals working processes include the melting of metal. 2. They started to the loading of the ship. 3. I was awakened by their loud taking. 4. He took part in the sitting of our group.

10. Перепишите следующие предложения, подчеркните в них инфинитив глагола и переведите предложения на русский язык, обращая внимание на функцию инфинитива.

1. То design new buildings is the work of аn architect.

2. То measures vоlumеs we must know the dimensions of а body.

3. Our plant was the first to install the automatic equipment.

4. The main purpose of the computers is to solve complex problems quickly.

11. Дайте полный ответ на следующие вопросы:

1. What is your name?

2. Where do you work?

3. What is your specialty?

4. Have you ever been in Moscow?

5. What is the weather like today?

6. Is it warm or cold for this season of the year?

7. How must you behave in the street?