ВАРИАНТ 3 I. Перепишите следующие предложения, подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму и залог. Переведите предложения на…

ВАРИАНТ 3

I. Перепишите следующие предложения, подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму и залог. Переведите предложения на русский язык.

1. Much work had been done for improving soil fertility on this farm.

2. Modern agriculture is developing in close contact with science and new technologies.

3. Our industry will increase the output of faster and more powerful tractors.

4. The driver usually increases speed gradually.

5. Some cities are so noisy and polluted that in many places vehicles have been banned in the city centre.

6. I was watching TV from 7 to 9 p. m. yesterday.

7. Ann had done her homework before her parents came.

II. В следующих предложениях подчеркните Participle I и Participle II установите функции каждого из них, т.е. укажите, является ли оно определением, обстоятельством или частью глагола-сказуемого. Переведите предложения на русский язык.

1. A letter sent from St. Petersburg today will be in Moscow tomorrow.

2. When sending the telegram, she forgot to write her name.

3. A fish taken out of the water cannot live.

4. They will be working at that time tomorrow.

5. He had translated the text before I came.

III. Работа с текстом:

a) переведите текст письменно на русский язык;

b) составьте глоссарий (13-15 слов или словосочетаний терминологического характера с их значениями);

с) письменно ответьте на вопросы.

EFFECTS PRODUCED BY A CURRENT

         The current flow is detected and measured by any of the effects that it produces. There are three important effects accompanying the motion of electric charges: the heating, the magnetic, and chemical effects, the latter is manifested under special conditions.

The production of heat is perhaps the most familiar among the principal effects of an electric current. The heating effect of the current is found to occur in the electric circuit itself. It is detected owing to an increase in the temperature of the circuit. This effect represents a continual transformation of electric energy into heat. For instance, the current which flows through the filament of an incandescent lamp heats that filament to a high temperature.

The heat produced per second depends both upon the resistance of the conductor and upon the amount of current carried through it. The thinner the wire is, the greater the developed heat is. On the contrary, the larger the wire is, the more negligible the heat produced is. Heat is greatly desirable at times but at other times it represents a waste of useful energy. It is this waste that is generally called "heat loss" for it serves no useful purposes and decreases efficiency.

The heat developed in the electric circuit is of great practical importance for heating, lighting and other purposes. Owing to it people are provided with a large number of appliances, such as: electric lamps that light our homes, streets and factories, electrical heaters that are widely used to meet industrial requirements, and a hundred and one other necessary and irreplaceable things which have been serving mankind for so many years.

The electric current can manifest itself in some other way. It is the motion of the electric charges that produces the magnetic forces. A conductor of any kind carrying an electric current, a magnetic field is set up about that conductor. This effect exists always whenever an electric current flows, although in many cases it is so weak that one neglects it in dealing with the circuit. An electric charge at rest does not manifest any magnetic effect. The use of such a machine as the electric motor has become possible owing to the electromagnetic effect.

The last effect to be considered is the chemical one. The chemical effect is known to occur when an electric current flows through a liquid. Thanks to it a metal can be transferred from one part of the liquid to another. It may also effect chemical changes in the part of the circuit comprising the liquid and the two electrodes which are found in this liquid. Any of the above mentioned effects may be used for detecting and measuring current.

Answer the questions.

1. What are three important effects accompanying the motion of electric charges?

2. How is the heating effect of the current detected?

3. What is heat loss?

4. What is the other way of the electric current manifestation?

5. When does the chemical effect of the electric current occur?

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