вар 1 What is an electric current?

Вариант 1
1.Перепишите следующие предложения и переведите их на русский язык,  обращая внимание на способы перевода инфинитива. Подчеркните инфинитив в английских предложениях.
1. To reduce current losses in electric wires voltage is increased and current is proportionally decreased.
2. The conductors to be used for transmitting the electric power to the trains are either the third rail or the overhead wire.
3. To convert a railway to electric haulage a costly reconstruction work is necessary.
2.Образуйте от данных глаголов две формы Participle I. Полученные причастия переведите на русский язык
Model: to read –    a) reading – читая, читающий;
                                   b) having read – прочитав
1) to offer; 2) to attend; 3) to bring; 4) to discover; 5) to find; 6) to do; 7) to say; 8) to obtain; 9) to deliver; 10) to shut; 11) to ring; 12) to declare; 13) to reduce; 14) to depart; 15) to implement.
3.  Перепишите и переведите предложения, обращая внимание на употребление Participle I . Подчеркните причастия I в английских предложениях и в переводе.
1. While reconstructing the tunnel the engineers equipped it for a.c. ( alternating current) electric traction.
•    2. Regenerative breaking is used on lines carrying high-density traffic.
3. Railway electrification attracts the attention of transport engineers in the countries facing the energy crisis.

4.  Образуйте Participle II от глаголов, данных в скобках. Полученные словосочетания переведите.
Model: a (to write) article – a written article – написанная статья.
1)    a (to damage) car; 2) freight (to transport) by railways; 3) an engine of (to improve) design; 4) (to weigh) luggage; 5) a (to choose) profession; 6) a (to restore) bridge; 7) a locomotive (to drive) by steam; 8) figures (to mention) in the report; 9) the (to forget) promise; 10) the distance (to cover) by train.

5.  Перепишите и переведите предложения, обращая внимание на употребление Participle II . Подчеркните причастия II в английских предложениях и в переводе.
1. The first method used in producing an electric current was chemical in nature.
2.  In the course of his experiments, A.Volt developed the first electric battery, a device known as a voltaic pile.
3.  Electronuclear machines more generally called particle accelerators, have played a vital role in the development of nuclear science and technology.

6. Перепишите и письменно переведите текст                                What is an electric current?
The question is often asked:”What is an electric current?”. No one has ever seen it. We only know of the existence of a current owing to its effects. A current can heat a conductor, it can have a chemical action when passing through a solution, or it can produce a magnetic effect. The practical unit of current is called the Ampere.
Two things are necessary to cause an electric current to flow: first- a complete circuit, and second –a driving force called the electromotive force.
A battery has a surplus of electrons on one of its two plates. If a copper wire is run from one plate to the other, a current flows in the complete circuit thus made. If a small bulb is placed in the circuit ,it will light up. If the batteries were disconnected and a generator substituted for it, we should have a typical lighting system. Both batteries and generators are the most common sources of electromotive force. The practical unit of electromotive force is the volt.
Current will flow more readily in some substances than in other. Such substances as porcelain, ebonite, rubber, glass are known as insulators. The practical unit of resistance is the Ohm.