3-21. For a given voltage, what determines the
amount of current that will flow in a
2. Spacing of the wires
3. Diameter of the wires
4. Characteristic impedance
3-22. When the impedance of a transmission
line is measured, which of the following
values frequently is NOT considered?
3-23. The characteristic impedance of a long
transmission line may be determined by
using which of the following methods?
1. Trial and error
2. Calculating the impedance of the entire
3. Calculating the impedances at each end
of the line
4. Adding the impedances of successive
3-24. When should lumped values for
transmission-line constants be used to
calculate characteristic impedance?
1. When the line is short compared to one
2. When the line is long compared to one
3. When the line is infinitely long
3-25. In actual practice, the characteristic
impedance of a transmission line is
usually within which of the following
1. 0 to 0.9 ohm
2. 1 to 49 ohms
3. 50 to 600 ohms
4. 601 to 1,000 ohms
3-26. The input impedance of a transmission
line is affected by which of the following
1. Radiation loss
2. Series inductance
3. Parallel capacitance
4. Each of the above
3-27. When a dc voltage is applied to a
transmission line and the load absorbs all
the energy, what is the resulting
relationship between current and voltage?
1. They are in phase with each other
2. They are equal to Z0 of the line
3. They are out of phase with each other
4. They are evenly distributed along the
3-28. The initial waves that travel from the
source to the load of a transmission line
are referred to as what type of waves?
3-29. Waves that travel from the output end to
the input end of a transmission line are
referred to as what type of waves?