2. Remember the new words and expressions:

• Electronic devices – електронні пристрої

• Vacuum tube – вакуумна трубка

• Applications - застосування

• Electronic industry – електронна промисловість

• Conductivity - провідність

• Insulators - ізолятори

• Heating - тепло

• Converting heat – зворотне тепло

• Thermocouples - термопари

• Photocells - фотоелементи

• sun-ray energy – енергія сонячного проміння

• Refrigerators – холодильні камери

3.Answer the following questions:

1. Has the transistor become an important member of electronic devices?

2. What does the term "semi-conductor" mean?

3. What elements do the semi-conductors include?

4. The conductivity of semi-conductors increases with heating, does not it?

5. Does the light as well as heat increase the conductivities of semi-conductors?

6. Are photocells capable of transforming 10 per cent of sun-ray energy into electric power?

4. Finish the sentences:

• The term "semi-conductor" means…

• They include such elements as…

• The conductivity of semi-conductors increases…

• Light as well as heat increases the conductivities of…

• Engineers and physicists see in them the way of…

• Converting heat' into electricity without using…

• This could be done by means of the thermocouples…

• Photocells made of semi-conductors are capable of …

5. Make up the dialogue about transistors, using the words from the text:

• semi-conductor

• elements

• increase

• Engineers and physicists

• Boiler

• 10 per cent

Unit 17.

PROTECTION AND CONTROL EQUIPMENT

1. Read and translate the text:

PROTECTION AND CONTROL EQUIPMENT

In electrical systems for the generation, distribution and use of electrical energy, considerable control equipment is necessary. It can be divided into two classes:

a) Equipment used at the generating and distributing end;

b) Equipment used at the receiving end of the system.

Safety switches are used at the point where the power enters a building. They are of the knife type and are usually enclosed in metallic boxes. A magnetic contactor is used to make and break the circuit at the points where considerable power is used.

An automatic starter is a device which is used to keep the current from being excessive while the motor is obtaining full speed. It is a kind of a resistance inserted in series with the direct current armature. As the motor obtains speed it gradually removes.

2. Remember the new words and expressions:

• electrical systems

• considerable

• control equipment

• generating

• distributing end

• receiving end

• safety switch

• the knife switch

• to make and break the circuit

• to keep the current from being excessive

• in series

• gradually removes

3. Make up the plan according to the text.

4. Translate into Ukrainian:

• поділятися на два класи

• контрольне оснащення

• аварійний вимикач

• послідовно

• металеві короби

• замикати і розмикати коло

• відсікач напруги

• поступово виводиться

• повна швидкість

• опір

5.Answer the questions:

1. What is necessary in electrical systems for the generation?

2. Can it be divided into two classes?

3. Are safety switches used at the point where the power enters a building?

4. They are of the knife type and are usually enclosed in metallic boxes, are not are?

5. Why is a magnetic contactor used for?

6. What is an automatic starter?

6. Complete the sentences using the words in brackets:

(power, knife type, to make and break the circuit, device, resistance)

1. Safety switches are used at the point where the…enters a building.

2. They are of the… and are usually enclosed in metallic boxes.

3. A magnetic contactor is used… at the points where considerable power is used.

4. An automatic starter is a… which is used to keep the current from being excessive while the motor is obtaining full speed.

5. It is a kind of a… inserted in series with the direct current armature

Unit 18.

Engineering Profession