Indicate whether each of the following statements is true or false. High frequen
ID: 1311513 • Letter: I
Question
Indicate whether each of the following statements is true or false. High frequency cable waves travel faster than low frequency cable waves. The frequency of a cable wave is the sanie as the frequency of the source of the wave. The voltage reflection coefficient will be -1 at a short circuited end of a cable. A piare standing wave results in a cable that terminates in an open circuit. Transmission line effects can be ignored if the length of the line is longer than l/4th of the wavelength of the signal.Explanation / Answer
A. True
As we increase ? from zero, the wave velocity increases from zero and approaches 1 / ?(LC). Thus high-frequency waves travel more quickly than low-frequency waves. Consider RG58/U cable at 1 kHz. We have ?L = 1.7 m?/m << R = 53 m?/m. So v = 25 m/?s at 1 kHz. As ? ? ? we have v ? 200 m/?s.
B. False
Impedance could occur between the source and the cable wave
C. True
Reflection coefficient of +1 is the result of a open circuit and reflection coefficient of -1 is the result of a short circuit
D. True
A pure standing wave is unachievable although it would lead to a large power loss.
E. False
Transmission line effects become negligible if length of the line is shorter than 1/4th of the wavelength of the signal.