5. Make up a dialogue about the electric currents. Use the following expressions:

- Is made up of tiny crystals;

- A regular and orderly arrangement;

- Electromotive force;

- Electric current;

- To measure;

- Direct current;

- Alternating current;

- Pulsating current.

6. Imagine that you are an electrician and some of your friends ask you about electric currents, try to explain it them.

7. Read the dialogue and make up your own one:

Teacher: When will electrons move?

Student: If given a path, electrons dislodged from the

parent atom, will move.

T: Well, what do you know about the electric current?

S: The electric current is a quantity of electrons

flowing in a circuit per second of time.

T: And what is the unit of measure for current?

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S: The unit of measure for current is the ampere. One

coulomb passing a point in a circuit per second, the

current strength is 1 ampere. The ampere is therefore a

rate unit.

T: Why do the electrons move along the circuit?

S: The electrons move around the circuit because the

e.m.f. drives them.

T: When is the rate of electron flow doubled?

S: It is doubled, if the force is doubled. It means that

other factors being constant, the current is directly

proportional to the e.m.f.

T: What other factor determining the magnitude of the

current do you know?

S: This is the ease with which the electrons are

allowed to pass along the circuit. This "ease" or

conductivity may be defined as the number of amperes

per volt in a circuit.

T: And when is a current proportional to the

conductivity?

S: All other factors being constant, the current is

directly proportional to the conductivity. If the

conductivity is doubled, the current will also doubled.

T: How is a magnetic field developed?

S: A stream of electrons in a circuit will develop a

magnetic field around the conductor along which the

electrons are moving.

T: What does the strength of the field depend upon?

S: The strength of the magnetic field depends upon the

current strength along the conductor.

T: And what about the direction of the field?

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S: The direction of the field depends upon the direction of the current flow. T: When is the current called direct or alternating? S: If the force causing the electron flow is unidirectional, the current is called direct. The force changing its direction of effort periodically, the current is known as alternating. T: That will do!

8. Translate into English:

Що таке сила струму? Це кількість електрики, яка проходить через коло за 1 секунду. Одиниця вимірювання сили струму - ампер. Електрорушійна сила рухає електрони в колі. Якщо е.р.с. подвоюється, то сила струму теж подвоюється. Відомо, що потік електронів у колі створює магнітне поле навколо провідника, по якому рухаються електрони. Напрула електричного струму залежить від сили струму в провіднику. Напрямок поля залежить від напрямку потока.