Exercises

I. Learn the following words, groups of words. Translate the sentences.

1. cell — элемент. A battery is an electrical cell.

2. electromotive force — электродвижущая сила. Elec­tromotive force is the subject of the present article.

3. excess — избыток, излишек. How can we use the ex­cess of generated electrical energy?

4. far apart — на расстоянии. We shall place these lamps far apart.

5. free — свободный. Free electrons move within all met­als.

6. in case — в случае. The current flows in case the cir­cuit is closed.

7. to influence — влиять. The temperature influences the conductance of metals.

8. movement — движение. The movement of free elec­trons constitutes the electrical current.

9. to offer resistance — оказывать сопротивление. All substances offer some resistance to the passing current.

10. potential difference — разность потенциалов. The elec­trical current flows if there is a potential difference.

11. provided — при условии. The resistance in electrol­ytes decreases provided their temperature increases.

12. reason — причина, основание. What is the reason for current leakage off the conductors?

13. size — размер. What is the size of a nuclear reactor?

14. to suspend — подвешивать. Insulator strings are sus­pended from the towers of transmission lines.

15. unit — единица; установка, агрегат. The ampere is the unit of current. A generator is a unit which generates electricity.

16. unless — если не. The current will not flow unless there is a potential difference in the circuit.

II. Translate the following words paying attention to prefixes.

disorder, interaction, impossible, unequal, misunder­standing, reread, unbalanced, immaterial, dissimilar, interplanetary, mispronounce, rearrange, reconstruct

III. Translate the following groups of words.

solar cell, to offer great resistance, large size, electrical units, free time, provided the distance is small

в некоторых случаях, электродвижущая сила, прос­той элемент, подвешивать лампы, избыток электронов, разность потенциалов, свободное движение

IV. Translate the following sentences.

a) 1. If an e.m.f. is applied to a path, the electrons will move towards the point of higher potential. 2. If people of the past had known that lightning was atmospheric elec­tricity, they would not have invented numerous stories about it. 3. If a wire were held against an electrified body, electricity would flow along the wire to its other end. 4. If coal were not used as fuel, we should get more valuable products.

b) 1. Were that liquid heated, it would greatly expand. 2. Were there no flow of current between A and В in any direction, then A and В would be at the same potential. 3. Were the electromotive force alternating, the current would be alternating as well. 4. Should you break the cir­cuit, no current would flow. 5. Had they used a larger wa­ter pipe for their last experiment, more water would have passed through that pipe 6. The current will flow around the circuit unless we break the circuit in some point.

V. Translate the following sentences and define the function of the word provided.

1. These electrical devices are provided with rubber insulators. 2. These electrical devices provided with rub­ber insulators were produced at a large factory. 3. These electrical devices can work for a long time provided they are made of high-quality material. 4. The electric current flows provided there is a complete circuit. 5. Lightning did not strike the house as it was provided with a lightning conduc­tor. 6. Ohm's law provided the possibility of determining resistance provided the voltage and current were known. 7. The electrons will jump through the air forming an elec­tric spark provided the potential difference becomes great enough.

VI. Complete the following sentences.

a) 1. If my friend comes to Moscow, we ... . 2. If I had time tomorrow, I ... . 3. If my friend had not entered the institute last year, he ... . 4. If I were you I ... . 5. If the teacher had given me the dictionary at the last les­son, I ... . 6. If my brother goes to England, he ... .

b) 1. He would have done it unless ... . 2. We should have gone to the country yesterday provided ... . 3. I should finish my work in time tomorrow unless ... . 4. She will answer all the teacher's questions provided ... .

VII. Translate the following sentences.

1. It was in 1800 that Volta first produced a continu­ous current. 2. It is the thermometer that measures the temperature of a substance. 3. It was M.V. Lomonosov who stated that heat phenomena were due to molecular motion. 4. It is the ampere that is the unit of current. 5. It is in Russia that atomic energy was first used for peaceful purposes. 6. It was A.S. Popov who was the inventor of the radio. 7. It is the difference of potential that causes the free electrons to flow from one point of the conductor to another.

VIII. For the words and expressions given in (a) find the Russian equi­valents given in (b).

a) 1. in the same manner; 2. generally speaking; 3. to turn one's attention; 4. on the basis of; 5. electrical engi­neering; 6. for this reason; 7. to meet requirements; 8. by means of; 9. nevertheless; 10. on the contrary; 11. to offer resistance; 12. under such conditions; 13. as well as; 14. as a result; 15. in spite of; 16. under consideration

b) 1. в результате; 2. рассматриваемый; 3. при по­мощи; 4. в таких условиях; 5. оказывать сопротивление; 6. вообще говоря; 7. тем не менее; 8. таким же образом; 9. обращать внимание; 10. электротехника; 11. удовле­творять требованиям; 12. несмотря на; 13. на основе чего-л.; 14. наоборот; 15. также, тоже; 16. по этой при­чине

IX. Put all possible questions to the following sentences.

1. The excess electrons will flow towards the point of deficiency.

2. The parallel circuit provides two or more paths for current flow.

X. Apply suitable adjectives to the following nouns.

difference, spark, force, wire, factor, resistance, conductor, ball

XI. Form new words of the same root, define what parts of speech they are.

active, differ, ease, conductance, resist, generator, turn

XII. Answer the following questions.

1. What force moves the electrons from one point to another? 2. What is an electromotive force? 3. Is the electromotive force measurable? 4. What unit is used for meas­uring an e.m.f.? 5. What devices may be used as a source of an e.m.f.? 6. What factors greatly influence the current flow in the circuit? 7. What does resistance depend on? 8. What materials are good insulators? 9. What factors can influence the resistance of an electrical circuit? 10. Does silver wire offer less resistance than an iron wire?

XIII. Speak on:

1. Electromotive force. 2. Resistance.

XIV. Make up the annotation of the text and retell it.