Упр. 8 Переведите на русский язык.

1. The electrical scientists work in laboratories, experimenting and testing and developing new ideas and principles about electrical action.

2. Being a good conductor, copper is often used in industry.

3. The atomic number and the atomic weight of any substance being known, you can easily determine the number of protons, neutrons, and electrons composing its structure.

4. A conductor of any kind being able to carry an electric current, a magnetic field is set up around the conductor.

5. Heating a substance we cause rapid motionof its molecules.

6. When an electric current flows through a resistance, there is a loss of energy as well as a loss of voltage or electric pressure, both these losses being directly proportional to the amount of resistance.

7. It is possible to measure the force causing a current to flow in the circuit,

8. The temperature being increased, the resistively of the semiconductor decreases.

9. Using energy of the atom we produce electric energy at the atomic power plants.

10. Electrons moving through a wire- electrical energy is generated.

Упр. 9 Переведите на русский язык, обращая внимание на способы перевода ” when (while)” + причастие.

  1 While explaining the results of the experiment, the professor wrote many formulas on the blackboard.

2. When rubbing a glass rod with a piece of silk you develop a large potential difference.

3. When finishing his experiment, lie carefully noted the results.

 

UNIT V.

TYPES OF CIRCUITS.

Lesson 1.

Text

Familiar Types of Circuits

Since you cannot see the electricity flow in circuits, you must "reason" where the current flows. To help you in such reasoning, make drawings or plans first. Then if it appears to work "on paper", do the wiring.

Any circuit is provided with a voltage source, a conductor, and a switch. A voltage source supplies current. A conductor is used lot connecting the elements of the circuit. A switch is used for controlling the current in the circuit.

There are many kinds of circuits, such as open circuits- closed circuits, short circuits, parallel circuits, and series circuits.

The circuit is said to be open when a switch is at rest or not being pressed or closed. A broken wire is an example of open circuits. An open circuit results in no current in it.

A closed circuit is simply a complete circuit. Pressing a pushbutton or making proper connections refers to closing circuits.

Short circuits are seldom desirable. They often result in damage. In other words, damage in the circuit often results from the short circuit. The short circuit refers to the conditions in the circuit which are the cause of fires, "blown" fuses, etc. Fuses are used as safety devices to stop the flow if it should become too great.

In everyday electric work, we very often deal with circuits where the current is divided between two or more branches. When a circuit is divided in such a manner that part of the current goes through one branch and part through another, it is called a parallel circuit.

A parallel circuit has the main line and parallel branches. In parallel circuits there is a difference between an open in the main line and an open in a branch. An open in the main line of a circuit of this type results in no current in the whole circuit while an open in a parallel branch results in no current in that branch only. This is the advantage of a parallel circuit.

When electrical devices are in a line so that the current is not divided at any point, they are said to be in series. The electric bell circuit is considered to be a typical example of a series circuit. The —(minus) terminal of each part of the circuit is joined to the +(plus) terminal of the next part, so that all the current does flow through each part of the circuit.

Words and word combinations:

familiar -обычный, знакомый

desirable –желаемый

complete – полный, завершенный, укомплектованный,

circuit – цепь, контур, схема, сеть

branch –ветвь, ответвления, отрасль

damage –повреждение, порча, ущерб

to appear- появляться

fuse –плавкий предохраниетель

seldom –редко

to refer – отсылать (к), ссылаться (на)

difference –разница

the electric bell –электрический звонок

trouble – неисправность, повреждение,нарушение

Assignment:

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

Электрические приборы, выключатель используется, повреждение цепи, главная линия, делится между двумя, источник напряжения, параллельная цепь, обычный виды электроцепей, предохранители используются как, причина пожаров, цепь короткого замыкания незамкнутая (разомкнутая) цепь, замкнутый интервал, последовательная цепь