II. Make up  ten different types of questions to the text.

III. Give Russian equivalents.

plug fuse, cartridge fuse, plug fuse has blown, short circuit, the carrying capacity of wire, open circuit, to take care of

IV. Translate the following pairs of words, paying attention to prefixes.

to move — to remove; to load — to overload; to write — to rewrite; to increase — to decrease; conductor — non-conductor; possible — impossible; to charge — to discharge; to heat — to superheat; to place — to replace; to make — to remake; to change — to unchange; to measure — to remeasure

V. Translate the sentences paying attention to the words underlined.

1. The flow of current forced through the tungsten causes heat, a white heat and this gives off light.

2. The above-mentioned phenomenon may be due to two causes.

3. Heating a substance we cause a more rapid motion of its molecules.

4. There must be a potential difference to cause electrons to move through the metal conductor.

5. The voltage being increased, the field becomes strong enough to cause electrons to produce additional ions by collisions.

VI. Translate the sentences.

1. Electric current will flow if there is a continuous path of conductors, i.e. an electric circuit.

2. If you increased the cross-section of a conductor, you would reduce its resistance.

3. We could charge an object by induction provided we held a charged body near the object to be charged.

4. If people of the past had known that lightning was atmospheric electricity, they would not have invented numerous stories.

5. We should not he able to change an object by induction, unless we brought a charged body near it.

 

VII. Translate the following sentences paying attention to the word "provided".

1. These electrical devices are provided with rubber insulators.

2. The electrical devices provided with rubber insulators were produced at a large factory.

3. These electrical devices can work for a long time, provided they are made of good material.

4. The electrical current flows provided there is a completed circuit.

5. Lightning did not strike the house as it was provided with lightning conductor.

6. Ohm's law provides the possibility of determining resistance, provided the voltage and current are known.

Lesson 5.

Text.

Storage Batteries

Something of the construction and care of storage batteries should be known in order to use them in correct way.

The usual automobile storage battery consists of three 2-volt cells assembled in a case. The top of each cell is covered and sealed. Every cell has a screw cap, which may be removed for testing or adding water. Each cell contains two groups of thin lead plates separated from each other by thin sheets of metal. These are immersed in a solution of distilled water and sulphuric acid in the proportion of one part of acid to two and one half parts of water, by volume. The solution of acid and water is known to be called the electrolyte.

One of the groups of plates is called positive and the other group is known to be the negative. The level of the electrolyte in each cell of a battery must be kept above the tops of the plates in order to insure proper performance. To do this, since only the water in the electrolyte evaporates, distilled water must be added from time to time. Do not overfill a battery, as the acid will eat the cable insulation or will corrode the terminals.

 

Words and word combinations:

construction – конструкция, сооружение

care – уход

а screw cap – ввертный болт

sulphuric acid – серная кислота

solution – раствор

assembled- смонтированный

case – емкость для хранения чего-либо

overfill – переполнять

sealed – опломбировать, герметически закрыть

are immersed – погружены

insure – страховать(ся), обеспечивать

 proper performance – должное функционирование,   

                           режим работы, эксплуатация

 evaporate – выпаривать

 corrode - вытравливать

Assignment:

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

Смонтированные в корпус, каждый элемент включает, раствор дисциллированной воды, называется электролитом, уровень электролита, время от времени, не переполняйте батарею.