1. Read and translate the text in a written form: The Questions that Stump Scientists

We’ve come to “the end of science”, writer John Horgan declared recently, saying that all the really important discoveries have already been made. An informal survey of young scientists in a variety of fields turned up some topics that might be worth a look. And one of them is high-temperature superconductors. Resistance (friction of electrons) is an unavoidable hassle for electrical devices-except for when it isn’t. Superconductors are materials that allow electricity to flow through them unimpeded, a kind of electronic perpetual motion. Once thought to occur only at the outrageously cold temperatures near absolute zero, the discovery of superconductivity at relatively balmy temperatures (as warm as 200 degrees Fahrenheit) was worth a Nobel Prize. But a decade later, there still isn’t a theory that can explain why it happens. “Every tool known to solid-state physics has been brought to bear on this problem”, says Doug Bonn, a physics professor at the University of British Columbia. Technical applications are already on the way, but the lack of a solid theory is holding things up.

2. Make up a plan of the text in the form of questions.

TEXT C

1. Mind the following words:

1. amber - бурштин

2. rubbed – натертий

3. investigate – досліджувати

4. sealing-wax rod –сургучна палка

5. repel – відштовхувати

2. Listen to the text “The nature of Electricity” and try to understand it.

3. Answer the following questions:

1. What did ancient Greeks observe with a piece of rubbed amber?

2. What did ‘electric’ mean?

3. When were the most discoveries in electricity made?

4. What do similar kinds of electricity do?

5. When do kinds of electricity attract each other?

UNIT 6

TEXT A

Transistor characteristics

1. Read and remember the words and their translations:

1. Small-dimensioned device-тонкомерний пристрій

2. radiant energy-промениста енергія

3. electrical conductive property-електропровідна властивість

4. insulator-ізолятор,діелектрик

5. resistance-опір

6. lead sulphide-сульфат свинцю

7. arsenic-миш’як

8. film-плівка

2. Match the words that go together. Translate them.

1. To consume a) resistance

2. To transform b) property

3. Sensitive to c) energy

4. To decrease d) power

5. To react to e) batteries

6. Electrical f) light

7. Solar g) infrared radiation

3. Read and translate the text:

Transistors made it possible to design compact, small-dimensioned electronic devices which consume very little power. The transistors are used for direct transformation of heat energy into electrical energy by means of thermal elements. They are also used to transform radiant energy into electricity with the help of photocells or so called solar batteries. In later years light sources and lasers were built on the basis of transistors. Transistors revolutionized radio engineering and electronics. Having small size and other properties, transistors make it possible to produce devices which cannot be made with vacuum tubes. Transistors are extremely sensitive to external influences, thousandths of one per cent of admixtures changing their electrical conductive properties by hundreds of thousands times. They are very sensitive to the action of light, nuclear particles, pressure, etc. Transistors being sensitive to light, engineers have to take this property into consideration. Some transistors act as insulators in the darkness, cadmium sulphide presenting one of them. But already under ordinary room temperature their resistances decrease millions of times. This property was used as the basis for making so called photoresistances. Some of them react not only to visible light but also to ultraviolet, infrared and X-rays and radioactive radiation. At present such photoresistances, being very small in size, are successfully used as the main elements for various measuring instruments and automatic devices. The supply of transistors is inexhaustible. But up to now only a limited number of them has been used for engineering purposes. Semiconductors are- germanium, silicon, selenium and some of the simple compounds like lead sulphide and arsenic and phosphorus with indium and gallium. The electrical properties of germanium may be changed, provided the latter is exposed to light. A very fine technology has been developed for obtaining transistors with preset physical properties by introducing into them admixtures of gold, copper, nickel, zinc, etc. Scientists have had considerable success in developing special films which protect the transistor crystals from outer influences and change their properties, these films making it possible to create a new family of miniaturized instruments.