Вопрос № 223090 - Английский язык

Прочитайте текст и определите, какой из заголовков соответствует тексту
Materials having a very high resistance are called insulators. Current passes through insulators with great difficulty.
The most common insulators are air, paper, rubber, plastics.
Any insulator can conduct current when a high enough voltage is applied to it. Currents of great value must be applied to insulators in order to make them conduct. The higher the resistance of an insulator, the greater the applied voltage must be.
When an insulator is connected to a voltage source, it stores electric charge and a potential is produced on the insulator. Thus, insulators have the two main functions:
1. to isolate conducting wires and thus to prevent a short between them and
2. to store electric charge when a voltage source is applied.

Прочитайте текст и определите, какой из заголовков соответствует тексту
Conductors are materials having a low resistance so that current easily passes through them. The lower the resistance of the material, the more current can pass through it.
The most common conductors are metals. Silver and copper are the best of them. The advantage of copper is that it is much cheaper than silver. Thus copper is widely used to produce wire conductors. One of the common functions of wire conductors is to connect a voltage source to a load resistance. Since copper wire conductors have a very low resistance a minimum voltage drop is produced in them. Thus, all of the applied voltage can produce current in the load resistance.

Прочитайте текст и определите, какой из заголовков соответствует тексту
Current transformers are used for operating ammeters, wattmeters, and other measuring devices. They produce in the meters a current lower than the measured current but proportional to it.
Current transformers also insulate the instrument from the circuit which is being measured. This is necessary for high voltage circuits.

Прочитайте текст и определите, какой из заголовков соответствует тексту
Current is a flow of electricity through a circuit. Let us consider two main types of current: direct and alternating. A direct current (d.c.) flows through a conducting circuit in one direction only. It flows provided a direct voltage source is applied to the circuit.
An alternating current (a.c.) is a current that changes its direction of flow through a circuit. It flows provided an alternating voltage source is applied to the circuit. Alternating current flows in cycles. The number of cycles per second is called the frequency of the current. In a 60-cycle alternating current circuit the current flows in one direction 60 times and in the other direction 60 times per second.

Прочитайте текст и определите, какой из заголовков соответствует тексту
Alternating current (a.c.) is converted into direct current by means of a rectifier.
A half-wave rectifier consists of a diode in series with a resistance. In order to put a rectifier into operation, a source of a.c. should be applied to it. When an a.c. source is applied the diode begins to conduct. The rectifier passes currents during positive half-cycles of the applied voltage. That is why it is called a half-wave rectifier. When the device operates direct current (d.c.) flows in the same direction. It is a pulsating current. Since pulsations should be eliminated, a filter is applied. Pulsations are eliminated by means of this filter.

Прочитайте текст и заполните пропуски подходящими по смыслу словами
Electronics is a rather young 1____________. It belongs to the twentieth century. Within a short period it has become a powerful means of progress.
Electronics surrounds us everywhere. Television, radio-receiving, tape-recording - are all based on 2_____________. The ideas of electronics are embodied in 3______________ technology and means of automation, biology and genetics which have 4______________ biotechnology as a new branch of the national economy.