1. Electron tubes can respond to very small control signal and produce a corresponding but larger signal.
2. Ammeters are connected in series with the circuit in which the current is to be measured.
3. Only a half wave of the a-c power supply is able to pass through the tube.
4. Acting at high speeds or high voltages, electron tubes can produce special radiations (such as radio or X-rays).
5. Since these vapour-filled tubes carry so much more current, their heated cathodes must be able to produce more electrons.
6. In the new model vacuum tubes must have been replaced by semiconductors.
7. While ordinary radio tubes will reach operating temperatures in 5 to 20 seconds, the vapour-filled tubes may need a longer warming time.
8. When the device or lead to which the battery is to be connected requires more current than can be taken safely from a single cell, the calls may be connected in parallel.
9. Suppose that two frequency changes are to be operated in parallel.
10. Other impurities, especially boron, which associates easily with silicon, must be removed or reduced to negligible level.
11. Chemical elements may be added to intrinsic silicon to alter its conductivity.
12. It can be said that the half-moon antenna has a simpler structure than the radial-mode horn.
13. However, there are some specific properties that distinguish semiconductors used for electronic devices from materials which generally might be said to have semiconducting characteristics.
14. To be useful for electronic device manufacture, the silicon must be obtained in its elemental form,that is free of oxygen, and also in its single crystal form.
15. It may seem strange that the silicon should first be purified at great expense, and then impurities added, however it is only in this way that a high degree of control can be exercised over the electrical conductivity.
16. The analysis should be performed at all frequencies over which the device has gain.
17. An out-of-band oscillation could possibly be at a large enough amplitude to cause a reduction in in-band gain or an increase in noise figure.
18. Stability should be analyzed so that the areas of potential instability can be evaluated and problem source and load impedances can be avoided.
19. The negative voltage can be supplied from a DC-DC converter driven by the same voltage regulator that feeds the active bias network.
20. For maximum mixer efficiency, the following additional guidelines should be followed.
21. Improved scattering and diffraction models for terrestrial and man-made targets must be developed to accurately predict the performance of a wireless system.
22. Equipment that has to be made is not complex and the rest is readily available in audio laboratories.
23. To maximize actuation performance the saturation magnetization should be maximized.
24. The type of over–voltage protection can be selected independently for each pad.
25. Observed spectra can be decomposed and compared against a library of laboratory spectra, so as to identify molecules and minerals.
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