21
3-22. Swr measurements are taken for which of
the following purposes?
1. To determine the output frequency of
the system under test
2. To determine the matching quality of
the transmission line termination
3. To determine the coupling quality of
the transmission line
4. To determine system output power
3-23. Couplers containing slots are used with rf
probes to provide access to which of the
following components?
1. Wavemeters
2. Unidirectional couplers
3. Open transmission lines
4. Waveguides
3-24. The wavelength of a standing wave is
measured on a short-circuited, terminated
line using a magnetic or electric probe in
which of the following ways?
1. By multiplying the average current by
the peak current
2. By dividing the average voltage by
the peak voltage
3. By measuring the distance between a
maximum voltage point and a
maximum current point
4. By measuring the distance between
alternate maximum or minimum
current points along the line
3-25. A neon lamp moved parallel to a two-
wire parallel transmission line will glow
at its brightest at which of the following
points?
1. Maximum current points
2. Maximum voltage points
3. Maximum voltage and current points
4. Maximum and minimum current
points
3-26. A milliammeter moved parallel to a two-
wire transmission line will show its
highest indication at which of the
following points?
1. Maximum voltage points
2. Maximum current points
3. Maximum current and voltage points
4. Maximum and minimum voltage
points
3-27. Which of the following devices may be
used to measure swr without measuring
the standing wave?
1. Bridge
2. Rf probe
3. Neon lamps
4. Milliammeter
3-28. When using an RC bridge to measure
swr, which of the following factor(s)
must you consider as the applied
frequency increases?
1. Skin effect
2. Stray inductance
3. Stray capacitance
4. All of the above
3-29. Before a newly constructed bridge can be
calibrated, adjustments must be made for
which of the following reasons?
1. To determine the frequency range of
the bridge
2. To keep stray effects at a minimum
3. To adjust the rf voltage amplitude
4. To determine the characteristic
impedance of the circuit
