№1. Which of the following terms does not belong to electronics?
Transistor, resistor, capacitor, contractor, processor.


The most advancing technology of the present industrial age is that of electronics. The introduction of the transistor in its day seemed a marvel of compactness compared with the glass vacuum tube. Now the size of electronic devices has been reduced by 10 every five years which has led to a great compression. When the term microelectronics first came into use, a chip of silicon a tenth of a square inch might hold 10 to 20 transistors, together with a few diodes, capacitors and resistors. Now such chips can contain thousands of separate electronic components.

Before the appearance of the transistor each type of component in an electronic circuit was made from one or more materials with the required electrical characteristics. For example, carbon was used for resistors, ceramics and a dielectric for capacitors, tungsten for emitters in vacuum tubes and so on. These components were then used like building blocks in creating a circuit with specified characteristics and responses. Circuits were combined into systems, such as a radio transmitter, a radio receiver, a radar set or a computer.

From the earliest days electronics has been a technology of complex interconnections. A small radar set can easily have as many interconnections as an oil refinery. To simplify a system design and reduce the number of interconnections engineers developed a series of standard circuit modules. Each module performed a specific function and was used as logical building block for creating the systems. The transistor could readily be assembled with resistors and capacitors of about the same size on a small plastic board. These modular circuit boards of the size of a playing card could then be plugged together as needed.

As transistor technology developed it was important to decrease the size of components and the length of interconnections. The physical limit of finding room for connections in an ever decreasing area was fast approaching. This limitation and the complexity of system design made the search for a new technology imperative.

The technology that resulted was microelectronics embodied in the integrated circuit. It made possible to produce (as a part of a single chip of silicon) transistors, diodes, resistors and capacitors joining them into a complete circuit.

The technology that produces such high-density electronic circuits is called large-scale integration, or LSI. Although the term has no precise definition, it is usually reserved for integrated circuits that comprise 100 or more “gates”, or individual circuit functions, with a density of 50,000 to 100,000 components per square inch. If the upper value could be achieved throughout a cubic inch of material, the density of electronic components would be about a fourth of the density of nerve cells in the human brain.

It now seems inevitable that microelectronic circuits, including LSI, will soon find their way into a variety of new applications which will have great impact on industry and everyday life.


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