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Recent questions tagged electromagnetics
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1
GATE ECE 2020  Question: 13
The impedances $Z=jX,$ for all $X$ in the range $\left ( \infty ,\infty \right )$, map to the Smith chart as a circle of radius $1$ with centre at $(0, 0)$. a point at the centre of the chart. a line passing through the centre of the chart. a circle of radius $0.5$ with centre at $(0.5, 0)$.
asked
Feb 13, 2020
in
Electromagnetics
by
jothee
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1.8k
points)

35
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gate2020ec
impedance
electromagnetics
0
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0
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2
GATE ECE 2020  Question: 21
A transmission line of length $3\lambda /4$ and having a characteristic impedance of $50$ $\Omega$ is terminated with a load of $400 \Omega$. The impedance (rounded off to two decimal places) seen at the input end of the transmission line is __________ $\Omega$.
asked
Feb 13, 2020
in
Electromagnetics
by
jothee
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1.8k
points)

28
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gate2020ec
numericalanswers
impedance
electromagnetics
0
votes
0
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3
GATE ECE 2020  Question: 43
For an infinitesimally small dipole in free space, the electric field $E_{\theta }$ in the far field is proportional to $e^{jkr/r}\sin\theta$, where $k=2\pi /\lambda$. A vertical infinitesimally small electric dipole $\left (\delta l \ll \lambda \right )$ ... field radiation pattern occurs at $\theta =60^{\circ}$, is $\lambda$ $0.5\lambda$ $0.25\lambda$ $0.75\lambda$
asked
Feb 13, 2020
in
Electromagnetics
by
jothee
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1.8k
points)

26
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gate2020ec
electromagnetics
radiationpattern
0
votes
0
answers
4
GATE ECE 2020  Question: 45
The magnetic field of a uniform plane wave in vacuum is given by $\overrightarrow{H}\left ( x,y,z,t \right )=(\hat{a_{x}}+2\hat{a_{y}}+b\hat{a_{z}})\cos\left ( \omega t+3xyz\right ).$ The value of $b$ is ___________.
asked
Feb 13, 2020
in
Electromagnetics
by
jothee
(
1.8k
points)

19
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gate2020ec
numericalanswers
planewavesandproperties
electromagnetics
0
votes
0
answers
5
GATE ECE 2020  Question: 46
For a $2$port network consisting of an ideal lossless transformer, the parameter $S_{21}$ (rounded off to two decimal places) for a reference impedance of $10 \Omega$, is __________.
asked
Feb 13, 2020
in
Electromagnetics
by
jothee
(
1.8k
points)

14
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gate2020ec
numericalanswers
impedance
electromagnetics
0
votes
0
answers
6
GATE ECE 2019  Question: 12
In the table shown, List I and List II, respectively, contain terms appearing on the lefthand side and the righthand side of Maxwell's equations (in their standard form). Match the lefthand side with the corresponding righthand side. ... $1Q,2R,3P,4S$ $1Q,2S,3P,4R$ $1R,2Q,3S,4P$
asked
Feb 12, 2019
in
Electromagnetics
by
Arjun
(
4.4k
points)

57
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gate2019ec
electromagnetics
maxwell'sequations
0
votes
0
answers
7
GATE ECE 2019  Question: 23
Radiation resistance of a small dipole current element of length $l$ at a frequency of $3$ GHz is $3$ ohms. If the length is changed by $1\%$, then the percentage change in the radiation resistance, rounded off to two decimal places, is ________ $\%.$
asked
Feb 12, 2019
in
Electromagnetics
by
Arjun
(
4.4k
points)

50
views
gate2019ec
numericalanswers
electromagnetics
radiationpattern
0
votes
0
answers
8
GATE ECE 2019  Question: 24
In the circuit shown, $V_{s}$ is square wave of period $T$ with maximum and minimum values of $8\: V$ and $10\: V$, respectively. Assume that the diode is ideal and $R_{1}=R_{2}=50\: \Omega.$ The average value of $V_{L}$ is _______ volts (rounded off to $1$ decimal place).
asked
Feb 12, 2019
in
Electromagnetics
by
Arjun
(
4.4k
points)

76
views
gate2019ec
numericalanswers
electromagnetics
waveequation
0
votes
0
answers
9
GATE ECE 2019  Question: 37
The dispersion equation of a waveguide, which relates the wavenumber $k$ to the frequency $\omega$ is $k(\omega)= (1/c) \sqrt{\omega^{2}\omega_{\circ}^{2}}$ where the speed of light $c= 2 \times 10^{8}\: m/s$ and $\omega_{\circ}$ ... $2 \times 10^{8}\: m/s$ $3 \times 10^{8}\: m/s$ $4.5 \times 10^{8}\: m/s$
asked
Feb 12, 2019
in
Electromagnetics
by
Arjun
(
4.4k
points)

63
views
gate2019ec
electromagnetics
waveguides
0
votes
0
answers
10
GATE ECE 2019  Question: 48
A Germanium sample of dimensions $1\: cm \times 1\: cm$ is illuminated with a $20\:mW,$ $600\: nm$ laser light source as shown in the figure. The illuminated sample surface has a $100\: nm$ of lossless Silicon dioxide layer that reflects onefourth ... bandgap is $0.66\: eV,$ the thickness of the Germanium layer, rounded off to $3$ decimal places, is ________ $\mu m.$
asked
Feb 12, 2019
in
Electromagnetics
by
Arjun
(
4.4k
points)

65
views
gate2019ec
numericalanswers
electromagnetics
0
votes
0
answers
11
GATE ECE 2019  Question: 51
A rectangular waveguide of width $w$ and height $h$ has cutoff frequencies for $TE_{10}$ and $TE_{11}$ modes in the ration $1:2$ . The aspect ratio $w/h$, rounded off to two decimal places , is _______.
asked
Feb 12, 2019
in
Electromagnetics
by
Arjun
(
4.4k
points)

35
views
gate2019ec
numericalanswers
electromagnetics
waveguides
0
votes
0
answers
12
GATE ECE 2016 Set 3  Question: 24
If a righthanded circularly polarized wave is incident normally on a plane perfect conductor, then the reflected wave will be righthanded circularly polarized lefthanded circularly polarized elliptically polarized with a tilt angle of $45^ \circ$ horizontally polarized
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

22
views
gate2016ec3
electromagnetics
polarization
0
votes
0
answers
13
GATE ECE 2016 Set 3  Question: 25
Faraday's law of electromagnetic induction is mathematically described by which one of the following equations? $\nabla\ \bullet \overrightarrow{B} = 0$ $\nabla\ \bullet \overrightarrow{D} = \rho_V$ ...
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

21
views
gate2016ec3
electromagnetics
0
votes
0
answers
14
GATE ECE 2016 Set 3  Question: 52
Consider an airfilled rectangular waveguide with dimensions $a=2.286\:cm$ and $b=1.016\:cm$. At $10 \:GHz$ operating frequency, the value of the propagation constant (per meter) of the corresponding propagation mode is _______
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

8
views
gate2016ec3
numericalanswers
electromagnetics
waveguides
0
votes
0
answers
15
GATE ECE 2016 Set 3  Question: 53
Consider an airfilled rectangular waveguide with dimensions $a=2.286\:cm$ and $b=1.016\:cm$. The increasing order of the cutoff frequencies for different modes is $TE_{01}<TE_{10}<TE_{11}<TE_{20}$ $TE_{20}<TE_{11}<TE_{10}<TE_{01}$ $TE_{10}<TE_{20}<TE_{01}<TE_{11}$ $TE_{10}<TE_{11}<TE_{20}<TE_{01}$
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

8
views
gate2016ec3
electromagnetics
waveguides
0
votes
0
answers
16
GATE ECE 2016 Set 3  Question: 54
A radar operating at $5\:GHz$ uses a common antenna for transmission and reception. The antenna has a gain of $150$ and is aligned for maximum directional radiation and reception to a target $1\:km$ away having radar crosssection of $3\:m^2$. If it transmits $100\:kW$, then the received power (in $\mu W)$ is _______
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

11
views
gate2016ec3
numericalanswers
electromagnetics
antennas
0
votes
0
answers
17
GATE ECE 2016 Set 3  Question: 55
Consider the charge profile shown in the figure. The resultant potential distribution is best described by
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

9
views
gate2016ec3
electromagnetics
0
votes
0
answers
18
GATE ECE 2016 Set 2  Question: 23
A uniform and constant magnetic field $\textbf{B}=\hat{z}B$ exists in the $\hat{z}$ direction in vacuum. A particle of mass $m$ with a small charge $q$ ... . Circular motion in the $xy$ plane. Linear motion in the $\hat{z}$ direction. Linear motion in the $\hat{x}$ direction.
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

25
views
gate2016ec2
electromagnetics
0
votes
0
answers
19
GATE ECE 2016 Set 2  Question: 24
Let the electric field vector of a plane electromagnetic wave propagating in a homogeneous medium be expressed as $\textbf{E}=\hat{x}E_{x}e^{j(\omega t\beta z)},$ where the propogation constant $\beta$ ... of the wave. The group velocity of the wave. The phase velocity of the wave. The power flux through the $z=0$ plane.
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

20
views
gate2016ec2
electromagnetics
0
votes
0
answers
20
GATE ECE 2016 Set 2  Question: 25
Light from free space is incident at an angle $\theta _{i}$ to the normal of the facet of a stepindex large core optical fibre. The core and cladding refractive indices are $n _{1}=1.5$ and $n _{2}=1.4$, respectively. The maximum value of $\theta _{i}$ (in degrees) for which the incident light will be guided in the core of the fibre is _________
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

10
views
gate2016ec2
numericalanswers
electromagnetics
opticalfiber
0
votes
0
answers
21
GATE ECE 2016 Set 2  Question: 53
A lossless microstrip transmission line consists of a trace of width $w$. It is drawn over a pratically 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 ... $Z_{0}< \sqrt{\frac{Lt}{\varepsilon _{0}\varepsilon _{\gamma}t}}$
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

30
views
gate2016ec2
electromagnetics
0
votes
0
answers
22
GATE ECE 2016 Set 2  Question: 54
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 reflection coefficient $\Gamma$ as a function of frequency $f$. The phase velocity of the signal in the transmission lines is $2\times 10^{8}$ $m/s$. The length $L$ (in meters) of $T_{2}$ is _________
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

11
views
gate2016ec2
numericalanswers
electromagnetics
transmissionlines
0
votes
0
answers
23
GATE ECE 2016 Set 1  Question: 25
The propagation constant of a lossy transmission line is $(2+j5) m^{1}$ and its characteristic impedance is $(50+j0) \Omega$ at $\omega = 10^6 rad \: s^{1}$ ... $L = 250 \: \mu H/m, C = 0.2 \: \mu F/m, R=50 \: \Omega /m, \: G=0.04 \: S/m$
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

28
views
gate2016ec1
impedance
electromagnetics
0
votes
0
answers
24
GATE ECE 2016 Set 1  Question: 52
An antenna pointing in a certain direction has a noise temperature of $50 \: K$. The ambient temperature is $290 \: K$. The antenna is connected to a preamplifier that has a noise figure of $2$ dB and an available gain of $40$ dB over an effective bandwidth of $12$ MHz. ... $T_e = 160.62\thinspace K$ and $P_{a0} = 4.6\times 10^{10}W$
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

9
views
gate2016ec1
electromagnetics
antennas
0
votes
0
answers
25
GATE ECE 2016 Set 1  Question: 53
Two lossless Xband horn antennas are separated by a distance of $200 \lambda$. The amplitude reflection coefficients at the terminals of the transmitting and receiving antennas are $0.15$ and $0.18$,respectively. The maximum directives of ... are perfectly aligned and polarization matched, the power ( in mW) delivered to the load at the receiver is _________
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

17
views
gate2016ec1
numericalanswers
electromagnetics
antennas
0
votes
0
answers
26
GATE ECE 2016 Set 1  Question: 54
The electric field of a uniform plane wave traveling along the negative $z$ direction is given by the following equation: ${\overrightarrow {E}^i_w= ( \hat {a}_x+ j\hat {a}_y)E_0e^{jkz}}$ This wave is incident upon a receiving antenna placed ... $5$dB Circular(clockwise), Linear, $3$dB Circular(anti clockwise), Linear, $3$dB
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

18
views
gate2016ec1
planewavesandproperties
electromagnetics
0
votes
0
answers
27
GATE ECE 2016 Set 1  Question: 55
The farzone power density radiated by a helical antenna is approximated as: ${\overrightarrow W_{rad}= \overrightarrow W_{average} \approx \hat {a_r}C_0\frac{1}{r^2}\cos^4\theta}$ The radiated power density is symmetrical with respect to $\phi$ ... maximum directivity of the antenna, respectively, are $1.5C_0,10dB$ $1.256C_0,10dB$ $1.256C_0,12dB$ $1.5C_0,12dB$
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

17
views
gate2016ec1
electromagnetics
antennas
0
votes
0
answers
28
GATE ECE 2015 Set 3  Question: 24
The directivity of an antenna array can be increased by adding more antenna elements, as a larger number of elements improves the radiation efficiency increases the effective area of the antenna results in a better impedance matching allows more power to be transmitted by the antenna
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

12
views
gate2015ec3
electromagnetics
antennas
0
votes
0
answers
29
GATE ECE 2015 Set 3  Question: 25
A coaxial cable is made of two brass conductors. The spacing between the conductors is filled with Teflon $(\varepsilon_{r} = 2.1, \tan \delta = 0).$ Which one of the following circuits can represent the lumped element model of a small piece of this cable having length $\Delta z$?
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

17
views
gate2015ec3
electromagnetics
0
votes
0
answers
30
GATE ECE 2015 Set 3  Question: 53
Consider the $3\:m$ long lossless airfilled 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 $(Z_{in})?$ Open Short Inductive Capacitive
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

17
views
gate2015ec3
electromagnetics
impedance
0
votes
0
answers
31
GATE ECE 2015 Set 2  Question: 24
In a source free region in vacuum, if the electrostatic potential $\varphi = 2x^{2} + y^{2} + cz^{2},$ the value of constant ܿ$c$ must be _______.
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

20
views
gate2015ec2
numericalanswers
electromagnetics
0
votes
0
answers
32
GATE ECE 2015 Set 2  Question: 25
The electric field of a uniform plane electromagnetic wave is $\overrightarrow{E} = \left(\overrightarrow{a}_{x} + j 4 \overrightarrow{a}_{y}\right) \text{exp }[j(2\pi \times 10^{7}t – 0.2z)].$ The polarization of the wave is right handed circular right handed elliptical left handed circular left handed elliptical
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

16
views
gate2015ec2
electromagnetics
0
votes
0
answers
33
GATE ECE 2015 Set 2  Question: 53
An airfilled rectangular waveguide of internal dimensions $a\: cm \times b\: cm\:(a>b)$ has a cutoff frequency of $6\:GHz$ for the dominant $TE_{10}$ mode. For the same waveguide, if the cutoff frequency of the $TM_{11}$mode is $15\: GHz,$ the cutoff frequency of the $TE_{01}$ mode in $GHz$ is __________.
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

13
views
gate2015ec2
numericalanswers
electromagnetics
waveguides
0
votes
0
answers
34
GATE ECE 2015 Set 2  Question: 55
The electric field of a plane wave propagating in a lossless nonmagnetic medium is given by the following expression ... The type of the polarization is Right Hand Circular Left Hand Elliptical Right Hand Elliptical Linear
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

19
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gate2015ec2
electromagnetics
propagation
0
votes
0
answers
35
GATE ECE 2015 Set 1  Question: 21
The polar plot of the transfer function $G(s) = \frac{10(s+1)}{s+10}$ for $0 \leq \omega < \infty$ will be in the first quadrant second quadrant third quadrant fourth quadrant
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

7
views
gate2015ec1
electromagnetics
polarization
0
votes
0
answers
36
GATE ECE 2015 Set 1  Question: 25
The electric field component of a plane wave traveling in a lossless dielectric medium is given by $\overrightarrow{E}(z,t) = \hat{a}_y 2 \cos \bigg( 10^st\frac{z}{\sqrt{2}} \bigg) \: V/m$. The wavelength (in m) for the wave is ___________.
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

19
views
gate2015ec1
numericalanswers
planewavesandproperties
electromagnetics
0
votes
0
answers
37
GATE ECE 2015 Set 1  Question: 37
All the logic gates shown in the figure have a propagation delay of $20$ ns. Let $A=C=0$ and $B=1$ until time $t=0$. At $t=0$, all the inputs flip (i.e., $A=C=1$ and $B=0$) and remain in that state. For $t>0$, output $Z=1$ for a duration (in ns) of ________.
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

16
views
gate2015ec1
numericalanswers
electromagnetics
propagation
0
votes
0
answers
38
GATE ECE 2015 Set 1  Question: 53
The longitudinal component of the magnetic field inside an airfilled rectangular waveguide made of a perfect electric conductor is given by the following expression ... and $b=0.033 \: m$. The mode of propagation inside the waveguide is $TM_{12}$ $TM_{21}$ $TE_{21}$ $TE_{12}$
asked
Mar 28, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

17
views
gate2015ec1
electromagnetics
propagation
0
votes
0
answers
39
GATE ECE 2014 Set 4  Question: 8
At $T=300 \:K$, the band gap and the intrinsic carrier concentration of GaAs are $1.42$ eV and $10^6 \: cm^{3}$, respectively. In order to generate electron hole pairs in GaAs, which one of the wavelength $(\lambda_C)$ ranges of incident radiation, is most suitable? (Given ... $1.62 \: \mu m < \lambda _C < 6.62 \: \mu m$
asked
Mar 26, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

9
views
gate2014ec4
electromagnetics
plank'sconstant
0
votes
0
answers
40
GATE ECE 2014 Set 4  Question: 11
If the emitter resistance in a commonemitter voltage amplifier is not bypassed, it will reduce both the voltage gain and the input impedance reduce the voltage gain and increase the input impedance increase the voltage gain and reduce the input impedance reduce both the voltage gain and the input impedance
asked
Mar 26, 2018
in
Electromagnetics
by
Milicevic3306
(
15.8k
points)

10
views
gate2014ec4
electromagnetics
impedance
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