1
GATE ECE 2016 Set 2
+2
-0.6
A lossless microstrip transmission line consists of a trace of width w. It is drawn over a practically infinite ground plane and is separated by a dielectric slab of thickness 𝑡 and relative permittivity $${\varepsilon _r}\, > \,1$$. The inductance per unit length and the characteristic impedance of this line are L and $$Z_o$$ respectively. Which one of the following inequalities is always satisfied?
A
$${Z_o}\, > \,\sqrt {{{Lt} \over {{\varepsilon _o}\,{\varepsilon _r}\,w}}}$$
B
$${Z_o}\, < \,\sqrt {{{Lt} \over {{\varepsilon _o}\,{\varepsilon _r}\,w}}}$$
C
$${Z_o}\, > \,\sqrt {{{Lw} \over {{\varepsilon _o}\,{\varepsilon _r}\,t}}}$$
D
$${Z_o}\, < \,\sqrt {{{Lw} \over {{\varepsilon _o}\,{\varepsilon _r}\,t}}}$$
2
GATE ECE 2015 Set 3
+2
-0.6
Consider the 3 m long lossless air-filled transmission line shown in the figure. It has a characteristic impedance of $$120\pi \,\Omega$$, is terminated by a short circuit, and is excited with a frequency of 37.5 MHz. What is the nature of the input impedance $$({Z_{in}})$$?
A
Open
B
Short
C
Inductive
D
Capacitive
3
GATE ECE 2015 Set 3
Numerical
+2
-0
A 200 m long transmission line having parameters shown in the figure is terminated into a load ܴ$$R_L$$. The line is connected to a 400 V source having source resistance $$R_S$$ through a switch, which is closed at t = 0. The transient response of the circuit at the input of the line (z = 0) is also drawn in the figure. The value of ܴ$$R_L$$ (in $$\Omega$$ ) is ___________.
4
GATE ECE 2014 Set 2
Numerical
+2
-0
In the transmission line shown, the impedance $${Z_{in}}$$ (in ohms) between node A and the ground is