Fixed resistors have

a) A constant value

b) A variable value

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

Cell, increase, output, voltage, stop operating, substitute, in case, in parallel, in series.

Additional material for card № 4

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.

A cell is used

a) To increase the voltage output

b) To reduce the current capacity

c) To supply electric energy

The terminals of a cell are used

a) To conduct current

b) To increase voltage

c) To connect the battery to a circuit

When cells are connected in series

a) All the positive terminals are connected together

b) All the negative terminals are connected together

c) The positive terminal of one cell is connected to the negative terminal of the second

Cells are connected in series in order

a) To increase the current capacity

b) To increase the voltage output

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