Power Engineering. Соколова Е.В. - 18 стр.

       2 The indirectly heated cathode consists of a metallic sleeve coated with emit-
ting substance, and is heated bywlraspassing through channels in a ceramic insulating
core placed the sleeve. The advantage of this construction is that entire cathode is at a
uniform potential, since it carries none of the heating current. It is therefore referred
to also as a unimpotential cathode. Another advantage is that the heater wires are so
close together that the current in them produces practically no magnetic field, which
otherwise would also affect the electron flow and thereby contribute to the hum in the
tube output.

      6.6 Переведите словосочетания

        a) wire filament, electron stream, tube elements, tube output, transformer wind-
ing, filament-heating current;
        b) this may cause fluctuations; they result in the development of hum in the
tube output; as much as possible; it is common practice

      6.7 Ответьте на вопросы

       1 What types of cathodes are employed in vacuum tubes? 2 What is common
practice to reduce the fluctuations as much possible? 3. Where is a ceramic insulating
core placed? 4. What is the advantage of the indirectly heated cathode?

      6.8 Переведите предложения

       1 Не would have connected these circuits much quicker.2This might cause
fluctuations which would result in the development of hum in the tube output. 3.
Were the temperature increased, the velocity of the molecular motion would be in-
creased. 4. Had the filament been heated, we should have obtained the electron emis-
sion. 5. It is essential that the entire cathode should be at a uniform potential. 6. It is
necessary that a means be provided for cooling the winding 7. Provided all the re-
quirements were met, the effciency of the apparatus would be increased. 8. If alternat-
ing current were used for heating, the different parts of the cathode would not be at
constant potential.

      6.9 Определите, какой частью речи являются слова

      frequently, constant, possible, advantage, practically ;ceramic, transformer.

      6.10 Прочтите диалог в ролях

      Dialogue

      A. I get excited at the thought that in a week I'll take my English exam.
      B. I'm sure everything will be all right. You are good at languages and you
have been working hard during this term.
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