Exercises:

1. Give Russian equivalents of the following phrases:

Unsheathed copper wires; highly susceptible; electromagnetic interference; communications media; insulated wire; related circuits; signal strength; long distances.

2. Say if the following sentences are true or false.

1. The earliest type of telephone line was referred to as open wire – sheathed copper wires strung on the telephone poles and secured by glass insulators. 2. Although open wire can’t be found in a few places, it has almost entirely been replaced with cable and other types of communications media. 3. These wide-diameter cables aren’t commonly used as telephone lines today and are often found in large buildings and under city streets. 4. Twisted-pair cable is susceptible to a variety of types of electrical interference (noise), which limits the practical distance that data can be transmitted without being garbled. 5. Cable is insulated wire.

3. Insert missing words, use the text’s vocabulary:

1. Although … can still be found in a few places, it has almost entirely been replaced with cable and other types of communications media. 2. Insulated pairs of wires … around each other- called twisted-pair cable- can be packed into bundles of a thousand or more pairs. 3. Twisted-pair cable is susceptible to a variety of types of electrical interference (noise). 4. Digital signals must be ‘refreshed’ every one to two miles through the use of an amplifier and related circuits. 5. Although … do increase the signal strength.

4. Translate these sentences into your native language:

1. Because it was uninsulated, this type of telephone line was highly susceptible to electromagnetic interference; the wires had to be spaced about 12 inches apart to minimize the problem. 2. These wide-diameter cables are commonly used as telephone lines today. 3. Twisted-pair cable is susceptible to a variety of types of electrical interference (noise), which limits the practical distance that data can be transmitted without being garbled. 4. To be received intact, digital signals must be ‘refreshed’ every one to two miles through the use of an amplifier and related circuits, which together are called repeaters.

5. Retell the text.

Text 3

Cables

Words and word combinations:

An insulated bundle – изолированная связка

threadlike fibers – нитевидные волокна

electric current – электрический ток

to distribute – распределять

to transmit – передавать

electronic devices – электронные устройства

intercontinental – межконтинентальный

fiber-optic cables – оптико-волоконные кабели

widespread – широко распространенный

artificial satellites – искусственные спутники

radio waves – радио волны

practical means – удобные средства

Cable, in electricity and communications, is an insulated bundle of wires or threadlike fibers that carry electric current or pulses of light. Cables are widely used to distribute electric power and to transmit communications signals. They are also used to connect parts of computers and other electronic devices. Electric cables range from intercontinental underwater cables that carry an electric current as small as one-thousandth of a watt to roadside electric lines that are capable of carrying thousands of watts of electricity. Fiber-optic cables transmit communications signals in the form of pulses of light.

Cables came into widespread use in the second half of the 1800’s, when telegraphs and telephones became common. Since the mid-1900’s, communications systems that use radio signals broadcast from transmitters on earth or in artificial satellites have begun to replace some cables. For example, telephone companies now use radio waves to carry most long-distance telephone calls. Communications satellites send television programs and other electronic messages throughout the world. In many cases, however, cables still provide the most practical means of communication.