GATE ECE
Electromagnetics
Transmission Lines
Previous Years Questions

Marks 1

The voltage of an electromagnetic wave propagating in a coaxial cable with uniform characteristic impedance is $$V(l) = {e^{ - \gamma l\, + \,j\,\ome...
A two wire transmission line terminates in a television set. The VSWR measured on the line is 5.8. The percentage of power that is reflected from the ...
The propagation constant of a lossy transmission line is (2 + j5) $${m^{ - 1}}$$ and its characteristic impedance is (50 + j0) $$\Omega $$ at $$\omega...
A coaxial cable is made of two brass conductors. The spacing between the conductors is filled with Teflon $$\left( {{\varepsilon _r} = 2.1,\,\,\tan \,...
In the following figure, the transmitter Tx sends a wideband modulated RF signal via a coaxial cable to the receiver Rx. The output impedance $${Z_T}$...
To maximize power transfer, a lossless transmission line is to be matched to a resistive load impedance via a $$\lambda /4$$ transformer as shown. ...
The return loss of a device is found to be 20 dB. The voltage standing wave ratio (VSWR) and magnitude of reflection coefficient are respectively.
A coaxial cable with an inner diameter of 1 mm and outer diameter of 2.4 mm is filled with a dielectric of relative permittivity 10.89. Given $${\mu _...
A transmission line of characteristic impedance 50 $$\Omega $$ is terminated by a 50 $$\Omega $$ load. When excited by a sinusoidal voltage source at ...
A transmission line has a characteristic impedance of 50 $$\Omega $$ and a resistance of 0.1 $$\Omega $$/m. If the line is distortionless, the attenua...
If the scattering matrix [S] of a two port network is $$$\left[ S \right] = \left[ {\matrix{ {0.2\,\angle \,\,{0^ \circ }} & {0.9\,\,\angle \,\...
Many circles are drawn in a Smith chart used for transmission line calculations. The circles shown in Fig. represent ...
The VSWR can have any value between
In an impedance Smith chart, a clockwise movement along a constant resistance circle gives rise to
A transmission line is distortionless if
The magnitudes of the open-circuit and short-circuit input impedances of a transmission line are 100$$\Omega \,$$ and 25$$\Omega \,$$ respectively. Th...
Assuming perfect conductors of a transmission line, pure TEM propagation is NOT possible in
All transmission line sections shown in Fig. have characteristic impedance $${R_0}\, + \,j0$$. The input impedance $${Z_{in}}$$ equals ...
A transmission line of 50$$\Omega $$ characteristic impedance is terminated with a 100 $$\Omega $$ resistance. The minimum impedance measured on the l...
A lossless transmission line having 50 $$\Omega $$ characteristic impedance and lenght $$\lambda /4$$ is short ciruited at one end and connected to an...
The capacitance per unit length and the characteristic impedance of a lossless transmission line are C and $$Z_0$$ respectively. The velocity of a tra...
A load impedance (200 + j0) $$\Omega $$ is to be matched to a 50$$\Omega $$ lossless transmission line by using a quarter wave line transformer (QWT)....

Marks 2

A microwave circuit consisting of lossless transmission lines $$T_1$$ and $$T_2$$ is shown in the figure. The plot shows the magnitude of the input re...
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 die...
Consider the 3 m long lossless air-filled transmission line shown in the figure. It has a characteristic impedance of $$120\pi \,\Omega $$, is termina...
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 havin...
In the transmission line shown, the impedance $${Z_{in}}$$ (in ohms) between node A and the ground is ...
For a parallel plate transmission line, let v be the speed of propagation and Z be the characteristic impedance. Neglecting fringe effects, a redution...
A transmission line with a characteristic impedance of 100 $$\Omega $$ is used to match a 50 $$\Omega $$ section to a 200 $$\Omega $$ section. If the ...
A transmission line of characteristic impedance 50 $$\Omega $$ is terminated in a load impedance $$Z_L$$. The VSWR of the line is measured as 5 and t...
In the circuit shown, all the transmission line sections are lossless. The Voltage Standing Wave Ration (VSWR) on the 60W line is ...
A transmission line terminates in two branches, each of length $$\lambda /4$$, as shown.The branches are terminated by 50 $$\Omega $$ loads. The lines...
One end of loss-less transmission line having the characteristic impedance of 75 $$\Omega $$ and length of 1 cm is short-ciruited. At 3 GHz, the input...
A load of 50 $$\Omega $$ is connected in shunt in a 2-wire transmission line of $$Z_0$$ = 50 $$\Omega $$ as shown in the Fig. The 2-port scattering pa...
The parallel branches of a 2-wire transmission line are terminated in 100 $$\Omega $$ and 200 $$\Omega $$ resistors as shown in the Fig. The character...
Characteristic impedance of a transmission line is 50$$\Omega $$. Input impedance of the open-circuited line is $${Z_{oc}} = 100\, + \,j\,\,150\Omega ...
Voltage standing wave pattern in a lossless transmission line with characteristic impedance 50 $$\Omega $$ and a resistive load is shown in Fig. Th...
Voltage standing wave pattern in a lossless transmission line with characteristic impedance 50 $$\Omega $$ and a resistive load is shown in Fig. Th...
A lossless transmission line is terminated in a load which reflects a part of the incident power. The measured VSWR is 2. The percentage of the power ...
Consider a 300$$\Omega $$, quarter-wave long (at 1 GHz) transmission line as shown in Fig. It is connected to a 10V, 50$$\Omega $$ sources at one end ...
Consider an impedance Z = R + jX marked with point P in an impedance Smith chart as shown in Fig. The movement from point P along a constant resistanc...
A short-circuited stub is shunt connected to a transmission line as shown in Fig. If $${Z_0} = 50\,\,\Omega $$, the admittance Y seen at the junction ...
In a twin-wire transmission line in air, the adjacent voltage maxima are at 12.5 cm and 27.5. The operating frequency is
In air, a lossless transmission line of length 50 cm with $$L = 10\,\mu H/m,\,\,C = 40\,\,pF/m$$ is operated at 25 MHz. Its electrical path length is...
If a pure resistance load, when connected to a lossless 75-ohm line, produces a VSWR of 3 on the line, then the load impedance can only be 25 ohms.
Consider a transmission line of characteristic impedance 50 ohm. Let it be terminated at one end by ( + j50) ohm. The VSWR produced by it in the trans...
A transmission line whose characteristic impedance is a pure resistance
The input impedance of a short-circuited lossless transmission line guarter wave long is
A 50 ohm lossless transmission line has a pure reactance of (j100) ohms as its load. The VSWR in the line is :
A two - wire transmission line of characteristic impedance $$Z_0$$ is connected to a load of impedance $${Z_L}({Z_L}\, \ne \,\,{Z_0})$$. Impedance mat...
A transmission line of pure resistive characteristic impedance is terminated with an unknown load. The measured value of VSWR on the line is equal to ...

Marks 5

The three regions shown in Fig. are all lossless and non-magnetic. Find (a) Wave impedance in mediums 2 and 3. (b) d such that medium 2 acts as a q...
A $${\lambda \over 2}$$ section of a 600 $$\Omega $$ transmission line, short ciruited at one end and open circuited at the other end, is shown in Fi...

Marks 10

A 200 volt (r. m. s) generator having an internal resistance of 200 ohm is feeding a loss-less transmission line. The characteristic impedance and the...
EXAM MAP
Joint Entrance Examination
JEE MainJEE AdvancedWB JEE
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Medical
NEET