1. Read the text, translate it and answer the questions.

Resistors

A resistor is one of the most common elements of any circuit. Resistors are used:

1. To reduce the value of current in the circuit;

2. To produce IR voltage drop and in this way to change the value of the voltage.

When current is passes through a resistor its temperature raises high. The higher is the value of current the higher is the temperature of a resistor. Each resistor has a maximum temperature to which it may be heated without a trouble. If the temperature rises higher the resistor gets open and opens the circuit. Resistors are rated in Watts. Some resistors have a constant value – these are fixed resistors, the value of other resistors may be varied – these are variable resistors.

1. What are the main functions of resistors?

2. What happens to resistor when its temperature rises high?

3. What is the name of resistors with constant value?

2. Find the correct variant.

1. A cell is used

1. To increase the voltage output

2. To reduce the current capacity

3. To supply electric energy

2. The terminals of a cell are used

1. To conduct current

2. To increase voltage

3. To connect the battery to a circuit

3. When cells are connected in series

1. All the positive terminals are connected together

2. All the negative terminals are connected together

3. The positive terminal of one cell is connected to the negative terminal of the second

4. Cells are connected in series in order

1. To increase the current capacity

2. To increase the voltage output

5. In order to increase the current capacity

1. Cells are connected in series

2. Cells are connected in parallel

3. Make up sentences, using words and word-combinations.

Capacitor, insulator, isolate, store, apply, move, great, frequency, prevent from, distance

Additional material for card № 5

1. Read the text, translate it and answer the questions.

Electric cells

An electric cell is used to produce and supply electric energy. It consists of an electrolyte and to electrodes. Electrodes are used ass terminals, they connect the cell to the circuit – current passes through the terminals and the bulb lights.

Cells can be connected in series, in parallel and in series-parallel. In order to increase the current capacity cells should be connected in parallel. In order to increase the voltage output cells should be connected in series. In case a battery has a large current capacity and a large voltage output, its cells are connected in series-parallel. When cells are connected in parallel their negative terminals are connected together and their positive terminals are also connected.

1. What is the function of electric cell?

2. What does an electric cell consist of?

3. How to connect electric cells?

2. Find the correct variant.

1. A capacitor is used

1. To supply voltage

2. To increase the voltage output

3. To store energy

2. The main parts of a capacitor are

1. Insulators only

2. Metal plates only

3. Metal plates and insulators between them

3. The function of insulators is

1. To store energy

2. To isolate the metal plates

3. To prevent a short between the metal plates

4. The capacity of a fixed capacitor

1. Is constant

2. Is varied

5. The capacity of a capacitor depends on

1. the size of plates

2. the distance between the plates

3. the material of the insulator