Vocabulary

Complete the definitions (1-9) below with the liTE3flK5iirailwords in the text.


 


                   
   
 
   
   
 
       
 
 
 

1 A
Optical fibres

.. . I3S

I(JP Optical fibres

Optical fibres started to replace some uses of copper cables in the 1970s. They are made from glass and are usually about 120 EJ25 jJJSsJs in MMilWWJ Some of themost common everyday uses are in telecommunications, close-circuit television (CCTV), and cable television.

1 ________________________________

Optical fibres carry signals more ^jjj^^fl than copper cable and with a much higher bandwidth. This means that fibres can carry more channels of information over longer distances.

2 _________________________________________________

Optical fibre cables are much lighter and thinner than copper cables with the same bandwidth. This means less space is needed in underground cabling U2HSJ

3 _________________________________________________

It is difficult to steal information from optical fibres. They are not harmed by electromagnetic interference, for example from radio signals or lightning. They don't BBffElso they can be used safely in [J222329atmospheres, for example in petrochemical plants.

4 _________________________________________________

Optical fibres are more expensive |^3 metre than copper. However, one optical fibre can carry many more signals than a single copper cable and the longer transmission distances mean that fewer expensive repeaters are required. Also, copper cable uses more electrical power to deliver the signals.

 

5 _________________________________________________

<L±

Optical fibres can't be spliced as easily as copper cable. Employees need special training yjUiilliliSme expensive nflffgfiTland measurement equipment.

Internet zone

Read the text again a» d match the headings (A-E) with the paragraphs (1-5).

A Training and skill> D Price
B Size and wiight E C ipacity

C Security


. is one

millionth of a metre.

2 The________ is the

distance across a circle.

3 A________ substance is

one that burns easily.

4 ________ means joining

the ends of two cables together.

5 To________ means to

start to burn.

6 ________ are tubes for

carrying cables.

7 ________ is a common

short way of saying 'for each.

8 ________ means to touch

with your hands.

9 ________ means in a way

that produces a good result and doesn't waste time, energy, or resources.