Highest voted questions in Electromagnetics / GO Electronics

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1

GATE ECE 2024 | Question: 5
Consider a lossless transmission line terminated with a short circuit as shown in the figure below. As one moves towards the generator from the load, the normalized impedances $z_{\text {inA }}, z_{i n B}, z_{i n C}$, and $z_{i n D}$ ... $z_{i n A}=+0.4 j \Omega, z_{i n B}=\infty, z_{i n C}=-0.4 j \Omega, z_{i n D}=0$

Consider a lossless transmission line terminated with a short circuit as shown in the figure below. As one moves towards the generator from the load, the norm...

admin

46.4k points

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admin asked Feb 16

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2

GATE ECE 2024 | Question: 29
A uniform plane wave with electric field $\vec{E}(x)=A_{y} \hat{a}_{y} e^{-j \frac{2 \pi x}{3}} \mathrm{~V} / \mathrm{m}$ is travelling in the air (relative permittivity, $\epsilon_{r}=1$ and relative permeability, $\mu_{r}=1$ ) in the $+x$ direction ( $A_{y}$ is a ... air (measured from $x=0$, in metres) is $\_\_\_\_\_\_\_$. $-\frac{3}{4}$ $-\frac{3}{2}$ $-6$ $-3$

A uniform plane wave with electric field $\vec{E}(x)=A_{y} \hat{a}_{y} e^{-j \frac{2 \pi x}{3}} \mathrm{~V} / \mathrm{m}$ is travelling in the air (relative permittivity,...

admin

46.4k points

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admin asked Feb 16

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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 $(0.5, 0)$.

The impedances $Z=jX,$ for all $X$ in the range $\left ( -\infty ,\infty \right )$, map to the Smith chart asa circle of radius $1$ with centre at $(0, 0)$.a point at the...

go_editor

1.9k points

169 views

go_editor asked Feb 13, 2020

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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 __________ $\Omega$.

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 t...

go_editor

1.9k points

172 views

go_editor asked Feb 13, 2020

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5

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 $\lambda$ $0.5\lambda$ $0.25\lambda$ $0.75\lambda$

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...

go_editor

1.9k points

229 views

go_editor asked Feb 13, 2020

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6

GATE ECE 2020 | Question: 45
The magnetic field of a uniform plane wave in vacuum is given by $\overrightarrow{H}\left ( x,y,z,t \right )=(\hat{a_{x}}+2\hat{a_{y}}+b\hat{a_{z}})\cos\left ( \omega t+3x-y-z\right ).$ The value of $b$ is ___________.

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+...

go_editor

1.9k points

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go_editor asked Feb 13, 2020

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7

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 __________.

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 $10 \Omega$, i...

go_editor

1.9k points

154 views

go_editor asked Feb 13, 2020

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GATE ECE 2019 | Question: 12
In the table shown, List I and List II, respectively, contain terms appearing on the left-hand side and the right-hand side of Maxwell's equations (in their standard form). Match the left-hand side with the corresponding right-hand side. ... $1-Q,2-R,3-P,4-S$ $1-Q,2-S,3-P,4-R$ $1-R,2-Q,3-S,4-P$

In the table shown, List I and List II, respectively, contain terms appearing on the left-hand side and the right-hand side of Maxwell’s equations (in their standard fo...

Arjun

6.6k points

175 views

Arjun asked Feb 12, 2019

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9

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 ________ $\%.$

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 ...

Arjun

6.6k points

181 views

Arjun asked Feb 12, 2019

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10

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).

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_{...

Arjun

6.6k points

232 views

Arjun asked Feb 12, 2019

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11

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 $\omega_{\circ}$ ... $2 \times 10^{8}\: m/s$ $3 \times 10^{8}\: m/s$ $4.5 \times 10^{8}\: m/s$

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 sp...

Arjun

6.6k points

167 views

Arjun asked Feb 12, 2019

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12

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 loss-less Silicon dioxide layer that reflects one-fourth ... bandgap is $0.66\: eV,$ the thickness of the Germanium layer, rounded off to $3$ decimal places, is ________ $\mu m.$

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 surfa...

Arjun

6.6k points

201 views

Arjun asked Feb 12, 2019

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13

GATE ECE 2019 | Question: 51
A rectangular waveguide of width $w$ and height $h$ has cut-off 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 _______.

A rectangular waveguide of width $w$ and height $h$ has cut-off frequencies for $TE_{10}$ and $TE_{11}$ modes in the ration $1:2$ . The aspect ratio $w/h$, rounded off to...

Arjun

6.6k points

182 views

Arjun asked Feb 12, 2019

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14

GATE ECE 2016 Set 3 | Question: 24
If a right-handed circularly polarized wave is incident normally on a plane perfect conductor, then the reflected wave will be right-handed circularly polarized left-handed circularly polarized elliptically polarized with a tilt angle of $45^ \circ$ horizontally polarized

If a right-handed circularly polarized wave is incident normally on a plane perfect conductor, then the reflected wave will beright-handed circularly polarizedleft-handed...