Unformatted text preview: 13.52 CHAPTER 13. TRANSMISSION LINES ::ll:::::1Q25%QZQZQZQWQZQZQZWZﬁﬂﬁﬂﬁxﬂzIE!!!|[::
Z62aMWQZQZWZﬂMQZﬂZKQZﬂZ§ﬁZQZQ z=-I z=0 Figure 13.57: Capacitive loaded transmission line. (1. If the source voltage is a step function given by V36) = 4u(t), ﬁnd and plot the
voltages V+(z, t), V_(z,t), V(z, t) on the transmission line at time t = 00. Problem 13.46: A coaxial cable with a polyethylene (5,. = 2.25) dielectric has an
inner radius “a” and an outer radius “12” such that (b/a) = 2.72. a. Determine the inductance and capacitance of a one—meter length of the cable and
then ﬁnd its characteristic impedance. b. A 4-m long length of the coaxial cable is charged to 100 volts and then disconnected
from the power supply so that the cable is open circuited at the source end. At time
t = 0 it is connected to a load having an impedance of 0.33 - Z0 ohms. Determine the
voltage across and current through the load, and the voltage across the open-circuited end of the cable as a function of time for times up to 0.1 as. Problem 13.47: A 5-km long transmission line, which is open—circuited at its out-
put end, has a distributed inductance of L2 : 0.4 ,uH/m, a distributed capacitance of
Ce = 40 pF/m, and negligible losses. A DC source of internal resistance, R5 = 50 Q,
and open—circuit voltage, VS = 10 V, has been connected to the line for 10 minutes.
At this time (t = 0), a load resistance of 100 Q is connected across the output end of
the line. a. By means of a bounce diagram, analyze the effect of connecting the 100—9 load.
Extend your diagram for a least three times the interval it takes for a disturbance to
travel the length of the line. b. At the time the initial disturbance reaches the source, what will be the voltage
across the line at its mid-point? c. Immediately after the initial disturbance reaches the source, What current will the source deliver? \/ ...
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- Fall '06