3 1-18.     In most applications, a designer would try to ensure that an electron tube operates at which of the following points on the curve? 1.    A   2.    B   3.    C   4.    D 1-19.     An electron tube operating at point A on the curve would have what plate resistance? 1. 7 k W 2. 10 k W 3. 30 k W 4.    100 k W 1-20.     An electron tube operating at point D can be said to be in what condition? 1.    Plate saturation   2.    Cathode saturation   3.    Both 1 and 2 above   4.    Normal operation _______________________________________ MATCH EACH ELECTRON- TUBE OPERATING CHARACTERISTIC IN COLUMN A WITH ITS CORRESPONDING CHARACTERISTIC- CURVE POINT IN COLUMN B. A. CHARACTERISTICS   B. POINTS   1-21.      Conduction occurs only at the outer fringe of the space charge   1.  A   1-22.      All the electrons of the space charge are attracted to the plate   2.  B   1-23.      The point at which the tube can be operated most efficiently   3.  C   4.  D _______________________________________ 1-24.     An electron tube is operated at 300 volts and a plate current of 60 milliamperes. To avoid being damaged, the tube must have what minimum plate dissipation rating?   1.    5000 watts   2. 18 watts   3. 5 watts   4. 0.18 watt 1-25.     Under which of the following conditions can a tube be considered operating beyond its peak inverse voltage rating? 1.    When the plates glow cherry red   2.    When current flows from the plate to the cathode   3.    When current flows from the cathode in the form of an arc   4.    When current flows from the cathode to the plate and damage occurs 1-26.     Why does control grid voltage of a triode exercise greater control than plate voltage over conduction of the tube? 1.    The grid is operated at a higher voltage than the plate   2.    The grid adds electrons to the electron stream   3.    The grid is closer to the plate than the cathode   4.    The grid is closer to the cathode than the plate 1-27.     The plate load resistor in an electron- tube circuit performs what function? 1.    It converts variations in plate voltage to current variations   2.    It limits the amount of plate voltage that can be applied to the tube   3.    It converts variations in plate current to variations in plate voltage   4.    It limits the amount of plate current that can flow through the tube