Вопрос № 347363 - Английский язык

Прочитайте текст и заполните пропуски подходящими по смыслу словами
When 1__________________ electrons suddenly strike a metallic 2_______________ they give up their kinetic 3_________________ to the electrons and atoms which they strike. Some of the bombarding electrons collide directly with free 4_________________ on the metal surface and may knock them out from the surface. The electrons freed in this way are known as secondary emission electrons, since the primary electrons from some other source must be available to bombard the secondary electron-emitting surface.

Прочитайте текст и заполните пропуски подходящими по смыслу словами
Thermionic emission is the most important and one most commonly used in electron 1_______________. In this 2________________ the metal is heated, resulting in increased thermal or kinetic 3________________ of the unbound electrons. Thus, a greater number of electrons will attain sufficient speed and energy to escape from the surface of the emitter. The number of electrons released per unit area of an emitting surface is related to the absolute 4_________________ of the cathode and a quantity of the work an electron must perform when escaping from the emitting surface.

Прочитайте текст и заполните пропуски подходящими по смыслу словами
We are finally ready to apply the knowledge we gained in previous sections about electrons, vacuum 1_________________ and transistors to some practical matters. In the following sections we shall consider a variety of circuits employing electron tubes and transistors. 2_________________ are combinations of tubes or transistors with other components, such as resistors, capacitors and inductors, and form the 3________________ building blocks of electronic systems: radio, automatic computer and so on. To understand the systems, you must be familiar with the circuits that 4_______________ them up.

Прочитайте текст и заполните пропуски подходящими по смыслу словами
Now we shall discuss amplifier circuits, or more specifically, audio amplifiers. 1 _________ is an electron tube or transistor circuit, which 2_________________ up an ac signal applied to its input. It is called a voltage amplifier if the magnitude of the output  3  __________ . From the amplifier is considerably greater than that of the input voltage. As a matter of fact the ratio of the output voltage to the 4__________________ voltage is called the amplification or gain of the amplifier.

Прочитайте текст и заполните пропуски подходящими по смыслу словами
When a number of 1_______________ are hooked up in series so that the output of one serves as the input to the next amplifier stage, the function of the early stages is usually to 2______________ up the voltage to a high level, while the last stage builds up the power to a level sufficient to operate an output device. Audio amplifiers amplify electrical ac 3_______________ that have a frequency range corresponding to the range of human hearing, or from about 20 to 15,000 cycles per 4________________.

Прочитайте текст и заполните пропуски подходящими по смыслу словами
The reflection of 1_______________ waves from aircraft had been observed in England in the early 1930s and the possibility for aircraft detection was discussed in 1934. It was soon realized that radio waves would be the 2________________ alternative to the existing inadequate acoustic warning equipment, which merely listened for the sound of aircraft 3________________ and had too short a range for proper warning of approach of last aircraft. In contrast, experiments indicated that radar could give a warning when the 4_________________ was 100 miles or more away.