IV. Language.

Exercise 1. Find the correspondence.

1. to increase voltage 2. negative terminal 3. opposite direction 4. electrical wires 5. charged particles 6. to meet industrial requirement 7. important statements 8. wide application 9. battery terminal 10. steel wire 11. minute particles

1. маленькі частинки 2. важливе ствердження (утвердження) 3. задовольняти вимоги промисловості 4. протилежний напрямок 5. стальний провід 6. збільшувати напругу 7. заряджені частинки 8. електричні проводи 9. негативно заряджена клема 10. широке використання 11. клема батареї

Exercise 2. Form six sentences combining suitable parts of the sentences given n columns I and II.

I II

1. The electric current is 1. The energy of position

2. kinetic energy is 2. electricity at rest

3. static electricity is 3. the flow of moving

4. Potential energy is 4. the energy of motion

5. The direct current is 5. a discharge of electricity

6. Lighting is 6. the flow of electrons in one direction

7. The alternating current is 7. the flow of electrons in one direction and then in the opposite one.

V. Comprehension.

Exercise 1. Find the wrong statements and correct them:

1. Electrons flow from the positively charged terminal of the battery to the negatively charged terminal.

2. Ampere supposed the current to flow from the negative pole to the positive one.

3. Static electricity is used for practical purposes.

4. Static electricity is not very high in voltage and it is easy to control it.

5. The direct current is known to flow first in one direction and then in the opposite one.

6. The direct current used for power and lighting purposes is assumed to do through 50 cycles a second.

Exercise 2. Answer the following questions:

1. Who first produced a source of continuous current ?

2. After whom was the unit of current named ?

3. Who determined the difference between the current and the static charges ?

4. What did Ampere suppose ?

5. When does a wire carry an electric current ?

6. What can you say about electrolytes ?

7. What do you call d.c. ?

8. What is the advantage of a.c. ?

9. Where is a.c. used ?

10. Who first applied a.c. ?

VI. Practice.

Exercise 1. Ask you group-mates the following questions. Let him / her answer them:

1. If electricity is a form of energy;

2. If there are two types of electricity;

3. If alternating voltage can be increased and decreased;

4. If Ampere determined the difference between the current and the static charges;

5. If the electric current can flow through liquids and through gases;

6. If the electrolytes change greatly when the current passes through them;

7. If a negatively charged electron will move to the positive end of the wire.

Exercise 2. Explain why:

1. static electricity cannot be used to light lamps, to boil water, and so on;

2. voltage is increased or decreased;

3. the unit of electric preassure is called volt;

4. Ampere was wrong as to the current direction;

5. the current is said to flow from the positive end of the wire to its negative end.

Exercise 3. Use the plan to speak about Electric Current:

1. Ampere`s supposition as to the current direction.

2. Electron and electric charge.

3. Substances, electric current can flow through.

4. D.c. and a.c. current.