II. Read and translate the text.

 

 

This is a circuit. Its elements are a voltage source, a resistor and a conductor. The circuit consists of a voltage source, a resistor and a conductor. A voltage source supplies current. A resistor reduces current. A conductor connects the elements of the circuit.

Compare circuit a with circuit b. What is the difference between them? Current passes through circuit a while no current passes through circuit b. Circuit b has an open. No cur­rent through circuit b results from an open. An open and a short are troubles in a circuit. A trouble in a circuit may result inno current in it.

III. Find English equivalents.

Цепь, обрыв, сокращать, снабжать, проводник, связывать, разница,

состоять из, повреждение, сравнение.

 

IV. Add necessary letter.

Circ-it, vol-age, resi-tor, curr-nt, sou-ce, eq-al, o-m, tro-ble, cond-ctor. 

V. Finish the sentences.

1. The circuit consists of….

2. A voltage source supplies….

3. A conductor connects……..

4. A trouble in a circuit may result…….

5. Current passes through………

VI. Complete these sentences, using the correct variant:

1. Circuit consists of          a) resistors and conductors.

                                            b) a voltage source and resistors.

                                             c) a voltage source, a resistor and a conductor.                                                             2. A voltage source             a) conducts current.

                                               b) reduces current.

                                                 c) supplies current

 3. A conductor                    a) connects the elements.

                                             b) supplies voltage.

                                              c) conducts current.

  4. A resistor                       a) connects the elements.

                                             b) supplies current.

                                             c) reduces current.

  5. No current results from   a) an open.

                                            b) a short.

 

 

VII. Solve these problems:

 

1.How much is the current in the circuit if a 60-volt source is connected

to a resistance of 1,600 ohms?

2.How much is the voltage in a circuit having a current equal to 25 amp,

if a 25-ohm resistance is connected to it?

3.A 70.35-ohm resistance is connected to the circuit. How much is the

voltage if the current equals 4.5 amp?

VIII. Pair work. Ask your group mate to compare circuits a and b (see Fig.1)

 

1.What do they have in common?

2.Which of the circuits has a trouble?

3.What does the trouble result from?

4.What does it result in?

 

IX. Answer the following questions:

1.What elements does a circuit consist of?

2.What is the function of a voltage source?

3.What is the function of a conductor?

4.What is the function of a resistor?

5.When is there no current in a circuit?

6.What does an open or a short result in?

ПРАКТИЧЕСКАЯ РАБОТА № 6

METERS

Цели: Введение и активизация в речи лексики по теме «Измерительные приборы».

Оборудование: комплект тестов, раздаточный материал.

 

                                     Vocabulary

I. Learn the words and expressions.

                              измерительный прибор

                             батарея

                              шкала

                             показания на шкале (прибора)

                             клемма

                             положительный

                            отрицательный

                            измерять