ekaterinasolda

10.09.2020 08:58

Английский язык

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1. What is polythene? 2. Where are polythene cables widely used?
3. When did their industrial production start?
4. What types of polythene cables are there?

What is polythene? It is a thermoplastic material used as insulator. Polythene is mainly
used in cases where a chemically-resistant plastic material is needed.
It is well-known fact that cables are classified as belonging to the main parts in the
modern communication systems. Cables used in communication differ in length, construction,
properties and cost. Polythene cables are widely used in transmitting electrical energy from area
to area. Polythene cables are comparatively new devices. Their industrial production started only
after World War II. They have many advantages: they may be used for both
a conductor insulation and a sheath which makes them one of the most usable substance in
industry.
There exist two types of polythene cables: the one having polythene insulation for the
conductors, and the other having paper insulation. The number of pairs in different cables is also
differen