IV. Перепишите предложения, подчеркнув в каждом из них глагол – сказуемое и определите его видо-временную форму и залог. Переведите предложения на русский язык.
1. As copper is a good conductor we were recommended to use it when we were carrying on our research work.
2. When the insulator is covered with a thin film of conducting electrolyte, a leakage current flows to ground over the insulator surface and this gives rise to heating.
ВАРИАНТ IV
1. Перепишите текст, письменно переведите его на русский язык.
THE TRANSFORMER
1.A transformer cannot be called a machine for it has no moving parts. We know the transformer to be an apparatus designed for changing voltages and currents by means of magnetic induction.
2.A two-winding transformer is known to consist of two coils so arranged that the magnetic lines of force of one coil pass through the other. Transformers being generally used only with alternating current, there is no need to make and break the circuit. The alternating current in one coil induces an e.m.f. in the other one because of the alternations in the value of the current in the first coil.
3.In order to strengthen the magnetic field passing through the coils of a transformer, a closed core of iron is generally used. The iron core provides a good path for the magnetic lines of force and nearly all the lines of force from one coil pass through the other, except the dissipation flux. An ideal transformer has no load losses. It means that all the lines of force of one coil pass through the other, and vice versa. However, the ordinary transformer is supposed to have no-load losses.
4.The coil on which the current is impressed on the input side of the transformer is called the primary, while the one from which the induced current is obtained on the output side is called the secondary. In case the secondary has more turns than the primary, the output voltage is larger than the input voltage and the transformer is called a step-up transformer. The secondary having fewer turns than the primary, the transformer is called step-down transformer.
5.If the same number of magnetic lines of force pass through two – coils, the ratio of the e.m.f.'s to be induced in the two coils is proportional to the ratio of the number of turns, in the two coils. In the transformer this means that the e.m.f. in the secondary is to e.m.f. in the primary as the number of turns in; the secondary is to the number of turns in the primary.
II. Выпишите из текста предложения, содержащие грамматические обороты:
1)объективный инфинитивный оборот (сложное дополнение) – 1 абзац;
2)субъективный инфинитивный оборот (сложное подлежащие) – 2, 3 абзацы;
3)Независимый причастный оборот – 2, 4 абзацы.
III. Переведите на русский язык следующие технические термины и словосочетания:
alternating voltage, magnetic inductions, magnetic line of force, value of current, core of iron, dissipation flux, non-load losses, primary coil of a transformer, secondary coil of a transformer, input voltage, output voltage, number of turns in a coil, step - up transformer, step - down transformer.
IV. Перепишите предложения, подчеркнув в каждом из них глагол – сказуемое и определите его видо-временную форму и залог. Переведите предложения на русский язык.
1. The coil which is supplied with current is called the primary winding of a transformer.
2. A transformer is used for changing the voltage or current value in an electrical circuit. It is the transformer which has made long-distance power transmission possible.
ВАРИАНТ V
1. Перепишите текст, письменно переведите его на русский язык.
ELECROMOTIVE FORCE
1.The electromotive force (e.m.f.) is the very force that moves the electrons from one point in an eclectic circuit towards another. The greater the electromotive force, the greater the pressure on the electrons moving through the conductor. A battery or other source of an electromotive force is simply a device that produces a potential difference necessary for causing electric current to flow along a conductor. We know the current to flow through a conductor in case there is a potential difference between the ends of the conductor, for it is then that an e.m.f. is present.
2.The e.m.f. is measurable, the volt being the unit in which it is measured. The unit of e.m.f. is the electromotive force of such a source of energy whose work on carrying one coulomb equals one joule.
3.One should distinguish between an electromotive force and a potential difference. A generator or a battery is a source of electromotive force, whereas the voltage across a resistance in which a current is flowing is a potential difference or voltage drop. In general, the e.m.f. of a battery or a generator cannot be measured exactly at its, terminals, since these devices have an internal voltage drop when the circuit is completed.
4.If an e.m.f. is applied to a path which allows the electrons to pass, they will move toward the point of higher potential, and then a current is said to flow in the circuit.
5.In a closed circuit consisting of a source of e.m.f., of metallic conductors and a device, the electric current is flowing from a plus terminal of a source of
e.m.f. to a minus terminal, giving up its energy in the, form of heat. When the current flows through a source of e.m.f. in the direction in which the e.m.f. tends to produce current energy is transferred from the source of e.m.f. to the circuit. Quite the opposite, the current flowing against the e.m.f., energy is transferred from the circuit to the source of e.m.f.
II. Выпишите из текста предложения, содержащие грамматические обороты:
1)объективный инфинитивный оборот (сложное дополнение) – 1 абзац;
2)субъективный инфинитивный оборот (сложное подлежащие) – 4 абзац;
3)Независимый причастный оборот – 2, 5 абзацы.
III. Переведите на русский язык следующие технические термины и словосочетания:
electric circuit, closed circuit, potential difference, unit of e.m.f., voltage drop, internal voltage drop, voltage across a resistance, terminals of a battery, to transfer energy, direction of e.m.f., to measure the e.m.f., resistance of a conductor.
IV. Перепишите предложения, подчеркнув в каждом из них глагол – сказуемое и определите его видо-временную форму и залог. Переведите предложения на русский язык.
1.If an e.m.f. is applied to a path, the electrons will motive toward the point of higher potential.
2.We have already seen that an electric current produces a magnetic effect.