- •Vocabulary 138
- •Electric current serves lis in a thousand ways
- •Exercises
- •Active Words and Expressions
- •Exercises
- •Exercises
- •Lightning
- •Active Words and Expressions
- •Exercises
- •Magnetism
- •Exercises
- •Idioms early history
- •Active Words and Expressions
- •Exercises
- •Lomonosov
- •Active Words and Expressions
- •Exercises
- •Volta's short biography
- •Electric current
- •Active Words and Expressions
- •What is heat?
- •Active Words and Expressions
- •Electric circuit
- •Voltmeter
- •Conductors and insulators
- •Active Words and Expressions
- •Exercises
- •Insulator surface treatment
- •Electromotive force and resistance
- •Active Words and Expressions
- •Exercises
- •Heating effect of an electric current
- •Active Words and Expressions
- •Exercises
- •III. Complete the following sentences:
- •IV. Answer the following questions:
- •V. Translate the following word combinations:
- •VI. Define the meaning of the prefixes in the following words, translate them:
- •IX. Translate tfie following sentences paying attention to the words in bold type:
- •X. Read and retell the following text.
- •If there were no electricity
- •XI. Speak on the heating effect of an electric current.
- •IV. Translate the following sentences and define the functions of tfie word that
- •V. Translate the following sentences paying attention to the words in bold type:
- •VI. Fill in the blanks with suitable prepositions and form sentences with the following infinitives: -
- •VII. Compare:
- •VIII. Translate the following sentences, paying atten- tion to the words in bold type:
- •IX. Form nouns from the following verbs and translate them:
- •X. Give a short summary of the text.
- •XI. Look at Fig. 9 and describe Oersted's discovery.
- •XII. Describe fig. 10.
- •VI. Read the following abbreviations:
- •VII. Define the following terms:
- •IX. Form five sentences combining suitable parts of the sentence given in columns I and II:
- •II. Answer the following questions:
- •IV. Define the following terms:
- •V. (a) Choose the right term; (b) explain the statement:
- •VI. Translate the following sentences:
- •VII. Translate the following text:
- •VIII. Retell the text.
- •Transformers
- •3 Single-pnase transformers stepping generator voltage up to 275.000 volts
- •2300 To 230 volt
- •2300 Volt motor
- •230 Volt induction motor
- •Transmission system
- •IV. Form as many words as possible using suffixes and prefixes. Define what parts of speech the new words are and translate them:
- •V. Form nouns from the following words using suitable suffixes:
- •VI. Translate the following word combinations:
- •VII. Arrange the following words and expressions in pairs of a) synonyms, b) antonyms:
- •IX. Compare:
- •X. Translate the following text:
- •XI. Retell the text
- •IV. Translate the following sentences using the Passive Voice:
- •V. Form sentences according to the models given below:
- •VI. Answer the following questions:
- •IV. Answer the following questions:
- •V. Define the following terms:
- •VI. Form six sentences using the following nouns quali- fied by adjectives:
- •VII. Translate the following text:
- •VIII. Describe Fig. 15.
- •IV. Translate the following sentences:
- •V. Translate the following sentences:
- •VII. Give a heading to each paragraph of the text. Explain why you have given such a heading.
- •VIII. Speak on:
- •IX. Translate the following text:
- •Active Words and Expressions
- •Exercises
- •IV. Translate the following words and word-combinations:
- •V. Answer the following questions:
- •VIII. Speak on the possible uses of solar energy.
- •IX. Read and retell the following story;
- •1. Energy
- •2. Electric fish
- •4. Surface tension
- •5. Electric meter
- •7. Refrigerator
- •10. Electron theory
- •11. Thermocouple and photocell
- •12. Electric lamp
- •13. Faraday's discovery
- •15. Steam turbine
- •16. Units of measurement
- •17. Plasma generator
- •18. Laser
- •19. Semiconductors
- •20. Steam power station
- •21. Hydroelectric power station
- •22. Current flow
- •23. Gases, solids, liquids and plasma
- •Idioms, Conjunctional and Prepositional Phrases
- •Vocabulary
- •Impulse wheel ['impals ,wi:l] активная турбина
1. Energy
What is energy? A scientist would say that energy is the ability to do work. You use energy when you walk. You carry your books with you to the Institute. It takes energy to carry books. You can do nothing without using energy. You wash with water warmed by energy. You put on clothes washed and ironed with energy.
There are many forms of energy. Each of these is useful to us. For example, we use heat energy to do a lot of useful things, namely, to heat our homes, to transport us from one place to another, and so on. Automobiles, trams, trains and airplanes are moved by changing heat energy to other forms of energy.
Electrical energy does many things for us. It is changed to other forms, such as: light, mechanical, heat, chemical, and others. When you watch television, you hear the sound and see the picture. The television (TV) set gets warm. Thus, electrical energy changes to heat, light and sound.
Many machines use electrical energy. They change energy from one form to another. Devices that are operated with electrical energy help us to work. Indeed, electricity plays, an important part in modern life.
2. Electric fish
The electric fish is mentioned in the oldest writings of man. History tells us that the Greeks and the Romans knew about it. They knew, for example, that any man coming into contact with the electric fish could obtain an electric shock. In later years, experiments were made to find out the nature and amount of the shock given by one of them
called the electric eel. The so-called electric eel is found in the tropical waters of South America.
Small electric eels, only one inch long, can give a small shock. However, by the time they are 6 inches long their internal battery gives as much as 200 volts. When it is quite grown a good electric eel can generate 600 volts. When it is short circuited, a current of 1 ampere can be obtained. A two-metre long eel could light a dozen 50 watt lamps.
The electricity in the electric eel seems to be produced at will. Besides, the discharges take place at speeds from 10 to 100 per second. It is interesting to mention here that the eel's head end is positively charged and the opposite end is negatively charged. By the way, the electric eel has some ability for finding polarity. Thus, if two charged electrodes are placed in water, even in the dark, the electric fish which is somewhere near the electrodes, will move towards the positive electrode, possibly thinking that it is the head of a friend.
3. APPLICATIONS OF THE ELECTROMAGNET
Electromagnets always find an application when it is , desirable to convert electrical energy into mechanical energy.
Telegraph systems and telephones, relays, motors and generators, radio sets and television sets, electrical measuring instruments as well as thousands of other valuable and necessary devices are known to contain electromagnets. They may be used, as well, to protect electrical circuits against overloads and underloads.
One of the first applications of the electromagnet was in telegraphy. Shilling, associate.member of the Petersburg Academy of Sciences, was the first to construct the electromagnetic telegraph. He demonstrated his invention as far back as 1832.
As mentioned above, the telephone also uses electromagnets, uses many of them, in fact. As soon as man learned to send word over the long wires of the telegraph circuit, the next problem to be solved was the telephone. Was it not possible to send the spoken word over similar wires? As a matter of fact, the first practical telephone was invented by the American scientist Bell in 1876 ?.nd was further improved by Edison.
HI