8. According to the dialogues ask your friend;

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1. - why he has chosen this speciality;

2. - what his favourite special subject is and why;

3. - what problems are solved by specialists of the specialists he has chosen.

9. Read the following dialogue and find some more information on the topic.

A: When was the first recorded observation about

electricity made?

B: As much as I know it was made by the Greek

philosopher Thales.

A: What did he state, I wonder?

B: Don't you know? He stated that a piece of amber

rubbed with fur attracted light objects such as feathers

and bits of straw.

B: Did he make any experiments?

A: No, as far as it is known Thales liked to do this but

he did not experiment systematically. Twenty two

centuries passed before there was any progress.

B: Oh, it was just about the time that Galileo

discovered the laws of the pendulum and accelerated

bodies. So it was at the time when the study of

magnetism and of electrical phenomena began.

A: How was it found out that some substances can be

"electrified"?

B: It is a well-known fact that having been rubbed

many substances behaved like amber did.

A: Can only similar substances become electrified or

acquire electrical charges, being touched together and

then separated?

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B: No. later on it was discovered that any two

unsimilar substances could be electrified. As a matter

of fact rubbing is not essential. It merely forces the

two substances into close contact.

A: When was the modern concept of the nature of

electricity arrived at?

B: The modem concept of the nature of electricity

arrived at the nineteenth century.

A: Yes, I know it quite well. Before an atom has been

regarded as the ultimate subdivision of matter. Today

an atom is regarded as an electrical system.

B: What do you know about a nucleus, a proton and

an electron?

A: In the electrical system there is a nucleus

containing positively charged particles. These

particles are called protons. The nucleus is surrounded

by the lighter negatively charged units - electrons. So,

the most essential constituent of matter is made up of

electrically charged particles.

B: I see that you have an idea about this but you didn't

tell me when matter is neutral.

A: But everybody knows that matter having equal

amounts of both charges is neutral - that it produces

no electrical effects.

B: And what happens if the number of negative

charges is unlike the number of positive ones?

A: Well, then the matter will produce electrical

effects. Having lost some of its electrons, the atom has

a positive charge; having an excess of electrons - it

has a negative charge.

B: So, as a matter of fact you do know the material.

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10. Answer the questions:

1. When were the ideas of the nature of matter and electricity arrived at?

2. How was an atom regarded up to the second half of the nineteenth century?

3. How is an atom regarded today?

4. What is matter now considered to be made up of?

5. What matter is neutral?

-

6. When does matter produce electrical effects?

7. When has an atom a positive charge?

8. When has an atom a negative charge?

11. Speak on the topic "Nature of electricity".

12. Make up a project "Electricity at Our Homes".

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Part 2

Classes of Electricity

1. Remember the words and word combinations:

Branch

Magnetism

Electrostatics

Electrodynamics

Property

Molecule

Substance

To store energy

A field of force

The arranged movement

At rest

Static electricity

Charge

A condenser plate

In motion

Dynamic electricity

To flow

Wire

2. Read and translate the text:

The study of electricity may be divided into three classes or branches: magnetism, electrostatics and electrodynamics. Magnetism is the property of the molecules of iron and certain other substances through which they store energy in a field of force because of

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the arranged movement of the electrons in their atoms. Electrostatics is the study of electricity at rest, or static electricity. Examples of this type of electricity are charges on condenser plates. Rubbing glass with silk produces static electricity. Electrodynamics is the study of electricity in motion, or dynamic electricity. The electricity which flows through wires for light and power purposes is a good example of the latter type of electricity.

This flow of electricity through a conductor is analogous to the flow of water through a pipe. A difference of pressure at the two ends of the pipe is necessary in order to maintain a flow of water. A difference of electric pressure is necessary to maintain a flow of electricity in a conductor. Different substances differ in electrical conductivity because of the ease with their atoms give up electrons. Electrical energy has intensity and quantity. Instruments have been devised which can be used to measure it in amperes and volts.

3. Answer the questions:

1. What classes or branches of electricity do you know?

2. What is magnetism?

3. What is electrostatics?

4. What is electrodynamics?

5. What is a good example of dynamic electricity?

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4. Match the words with their definitions:

1) Magnetism a) is the study of electricity at rest

2) Electrostatics b) is the property of the molecules

of iron

3) Static electricity c) is the study of electricity in

motion

4) Electrodynamics d) is the study of electricity at

rest •

5. Translate into English:

1. Науку про електрику можна поділити на три класи або галузі.

2.Електродинаміка — наука про електрику в русі. 3. Електростатика - наука про електрику в спокої.

6. Make up a dialogue about the classes of electricity. Use the following expressions:

- To arrange movement;

- Three classes;

- The study of electricity;

- This type of electricity

7. Learn the following terms used in electricity:

Alternating current is an electric current that reverses the direction of its flow many times a second.

Conductor is a substance that transmits electricity.

Direct current is an electric current that flows in only one direction.

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Electric current is a flow of electrons or ions.

Electric circuit is the path or paths followed by an electric current.

Electric field is the space around a charged particle in which its charge has an effect.

Electric induction is the process by which an electrically charged object charges another object without touching it.

Electromotive force, also called voltage, is the pressure that pushes an electric current through a circuit.

Electron is a particle of an atom that carries one unit of negative charge.

Fuse is a device that prevents too much current from flowing through a circuit.

Insulator is a substance that conducts hardly any electricity.

Ion is an atom that has either gained or lost electrons and is electrically charged.

Proton is a particle of an atom that carries one unit of positive charge.

Resistance is the opposition to the flow of an electric current in a circuit.

Rheostat is a device that increases the resistance in an electric current.

Semiconductor is a substance that conducts electricity better than insulator but not as well as a conductor.

Static electricity is electrons or ions that are not moving.

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Transformer is a device that increases or decreases the voltage of alternating current.