B. Text Study

I. Look at the title of the text. Make your predictions about the content of it. Read the text and answer the question.

When can people get an electric shock?

Text B

ELECTRIC SHOCK AND SAFETY ELECTRIC SYSTEM

The strength of current depends on both the voltage and the resistance in a circuit. A current of 50 ma is dangerous for a man; it may result in an electric shock. One gets an electric shock in case one touches live conductors when the power is on. And a current of 100 ma and higher is lethal. Thus, before working on a circuit, deenergize it and work on it with the power off.

Earthing system serves to protect attending personnel from electric shocks when voltage арреаrs on parts that are normally dead. The risk of an electric shock decreases with decreasing voltage. In wet and hot atmosphere the risk of electric shock increases. Safe voltage for circuits used in dry atmosphere is under 36 V. When the power is on contacts live conductors are dangerous for life. When a live conductor is touched with both hands the resistance of the conductor is from 10,000 to 50,000 ohms. When a live conductor is touched with one hand the resistance is much higher. The higher is the body resistance, the smaller is the current that flows through the body. Take it into consideration and work with one hand if the power is on! Or work on the circuit with the power off!

Thus measures are taken to protect attending personnel from contacts with live parts of installations under voltage.

The danger of electric shock disappears provided the metal parts of installations under voltage are connected with ground by means of safety earthing. Connecting to ground is made by means of measuring devices. The faulty parts should be detected, eliminated, and replaced by new ones.

II. Read the text and define whether the following statements are true or false.

1. A current of 60ma isn’t dangerous for a man.

2. When the power is on it’s possible to get an electric shock.

3. It’s impossible to protect people from electric shocks by means of earhting system.

4. The risk of electric shock decreases in wet and hot atmosphere.

5. The risk of electric shock is much higher when a live conductor is touched with one hand.

III. Expand the sentences.

1. The strength of current depends on both ….

2. One gets an electric shock in case ….

3. Safe voltage for circuits used in dry atmosphere is ….

4. When the power is on contacts live conductors are ….

5. The resistance of the conductor is from 10,000 to 50,000 ohms when ….

6. The higher is the body resistance, the smaller ….

7. The danger of electric shock disappears provided ….

IV. Now decide which of the following statements express important ideas or supporting details for this reading.

1. a) A current may be dangerous for a man, it may result in an electric shock.

b) One gets an electric shock in case one touches live conductors when the power is on.

c) A current of 100ma and higher is lethal.

2. a) When a live conductor is touched with both hands the resistance of the conductor is from 10,000 to 50,000 ohms.

b) When a live conductor is touched with one hand the resistance is much higher.

c) The higher is the body resistance, the smaller is the current that flows through the body.

3. a) Earthing system serves to protect personnel from electric shocks.

b) Connecting to ground is made by means of measuring devices.

c) The faulty parts should be detected, eliminated, and replaced by new ones.

d) Safety measures should be taken to protect people from electric current.

V. Find the words – carriers of the primary and the secondary information in paragraph 1.

VI. Define the function of commas in paragraph 2.

VII. Find out the means of connection between clauses, parts of the sentence and sentences.

VIII. Arrange the sentences in the logical order according to the text.

1. Earthing system serves to protect attending personnel from electric shocks.

2.The strength of current depends on the voltage and resistance in a circuit.

3. Сurrent may result in electric shock.

4. It is necessary to work with one hand if the power is on or work with the power off.

IX. Give the main points of the text in 4-5 sentences.

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