Exercises

I. Read the following words:

core, source, vary, merely, circuit, winding, design, frequency, primary, secondary; molecular, essentially, sufficiently, efficiency, eliminate, prohibitive; hysteresis.

II. Find in the text English equivalents for the following words and make up sentences, using them:

в отличие от, по сути, в соответствии, вдвое больше, иметь силу (оставаться в силе), и наоборот, поэтому, точно так же, как; согласно, поскольку.

III. Find in the text antonyms for:

different, the former, to increase, useless.

IV. Give as many English equivalents as you know for:

применять, превращать, спокойный, состоять из, соединять, также, только, называться, величина, сила, дважды, иметь силу, следовательно, уменьшать, желать, различный.

V. Translate into English:

Приборы, преобразующие токи с изменением их силы и напряжения, называются трансформаторами. Известно, что первый трансформатор построен в 1882 году русским изобретателем - самоучкой И. Ф. Усагиным.

Трансформатор называется повышающим, если он повышает напряжение, и понижающим, если он понижает напряжение.

На электростанции устанавливаются трансформаторы, повышающие напряжение, тогда как на месте потребления устанавливаются понижающие трансформаторы.

Мы знаем, что понижение напряжения необходимо потому, что электрические потребители электроэнергии работают обычно с напряжением в 120 - 220 вольт.

VI. Answer the following questions:

1. What is a generator used for?

2. What is a transformer used for?

3. What does a transformer consist of?

4. What kinds of cores do you know?

5. How does the electromagnetic field around the primary coil change if a varying voltage is applied to it?

6. What does the value of the induced emf' depend upon?

7. How are transformers classed?

8. When does the inductive reactance of the transformer increase?

9. Where must air core transformers be used?

VII. Describe the figure.

Упражнения к лекции 2. Перевод как вид языковой деятельности

Choose one of the topics below and prepare to talk about it:

1. Academician A. F. Yoffe - his biography and the beginning of his scientific activity.

2. The theory of semiconductors at that time.

3. Academician Yoffe's views upon scientific research in general.

4. The problem of direct conversion of solar energy into electricity.

5. The use of semiconductors nowadays.

MICHAEL FARADAY

Michael Faraday (1791 - 1867), the great English experimental physicist, was born in the family of a blacksmith, his early life being spent earning his living as a bookbinder's apprentice. Taking time from his work to read some of the books passing through his hands, Faraday became intensely interested in science. He even performed such of the simpler experiments as he could afford out of his meager wages.

He happened to attend four lectures on chemistry by Sir Humphry Davy in 1812. Disliking his trade as a bookbinder, he applied to Davy for a position. As proof of his earnestness Faraday sent along with his application the notes he had taken of Davy's four lectures. Davy became so interested that he engaged Faraday in 1813 as apparatus assistant. In 1814 - 15 Faraday travelled with Davy on the continent and saw many of the continental scientists. He was encouraged by Davy to begin original research, and in 1816 he published his first paper. In 1819 he published six papers more. In 1818 eleven; and in 1819 nineteen papers. This remarkable output was attained in spite of Faraday's having no university training. As a matter of fact, he was almost entirely self-taught.

About 1820 he began his electrical researches which resulted in the famous discovery of the motion of a wire carrying a current in the field of a magnet. Since a current-carrying wire would move in a magnetic field, should not the reverse be true and a magnet be made to produce current in a wire? For days he experimented with magnets and coils of wire until in desperation he plunged a magnet down into a coil and observed that a current was generated in the coil. Why had he not discovered this before? The motion was the thing; it was the connecting link he had failed to realize. For this discovery the whole scientific world paid him due tribute.