4.
Several methods of coupling are used to transfer energy into, or out
of, waveguides. The device that is used to remove samples of energy
from a waveguide and transfer these samples to associated test
equipment is a
a.
directional coupler.
b.
dummy load.
c.
horn.
d.
loop.
5.
If a rotating choke joint is used to couple two sections of waveguide
together, the two physical sections appear as one electrical section.
Why does the choke joint make the two waveguide sections appear as one
electrical section?
a.
The choke joint
appears
as
a
half-wave
open
circuit
to
the
waveguides.
b.
The choke joint appears as a half-wave short circuit to the
waveguides.
c.
The choke joint
appears
as
a
half-wave
open
circuit
to
the
waveguides.
d.
The choke joint appears as a quarter-wave short circuit to the
waveguides.
6.
Twisted sections of waveguide must be at least two wavelengths long to
prevent reflections and loss of power. Twisted sections of waveguide
are used primarily to
a.
change the polarization of the waves.
b.
connect waveguides to directional couplers.
c.
connect fixed waveguides to rotating waveguides.
d.
match the load impedance to the characteristic impedance of the
waveguide.
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