14. The beam-forming plates in a beam power tube create an electric
plane called the virtual cathode.
The purpose of this virtual
cathode is to
a.
repel the secondary electrons emitted from the plate.
b.
repel the electrons emitted from the actual cathode.
c.
increase the plate resistance of the tube.
d.
increase the screen current.
15. If a pentode's screen and suppressor grid leads are connected to
the plate lead, the pentode's characteristics will more closely
resemble those of a
a.
c.
b.
triode.
d.
beam power tube.
16. Assume that, as an experiment, you rewind the wires of the
control grid of a pentode so as to make it a variable- pentode. How
will this "new" tube differ in its operation from one with a
conventional control grid?
a.
The plate current will become independent of plate voltage at
lower plate potentials.
b.
The plate resistance will increase at low values of grid
bias.
c.
The grid-bias cutoff voltage will be greater.
d.
The grid current will increase.
17.
The suppressor grid in a pentode is located between the
a.
control grid and the screen grid.
b.
cathode and the control grid.
c.
screen grid and the plate.
d.
screen and the cathode.
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