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Recent questions tagged analog-communications

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GATE ECE 2005 | Question: 71
A signal as shown in the figure is applied to a matched filter. Which of the following does represent the output of this matched filter?
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GATE ECE 2005 | Question: 73
A carrier is phase modulated (PM) with frequency deviation of $10 \; \mathrm{kHz}$ by a single tone frequency of $1 \; \mathrm{kHz}$. If the single tone frequency is incr...
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GATE ECE 1995 | Question 1.36
The image (second) channel selectivity of a super beterodync communication receiver is determined byantenna and preselectorthe preselector and $\text{RF}$ amplifierthe pr...
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GATE ECE 1995 | Question 1.37
For a narrow band noise with Gaussian Gradrature components, the probability density function of its envelope will beuniformGaussianexponentialRayleigh
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GATE ECE 1995 | Question 1.38
If the number of bits per sample in a $\text{PCM}$ system is increased from improvement in signal-to quantisation noise ratio will be$3 \mathrm{~d B}$$6 \mathrm{~d B}$$2...
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GATE ECE 1995 | Question 1.39
A $\text{PLL}$ can be used to demodulate$\text{PAM}$ signals$\text{PCM}$ signals$\text{FM}$ signals$\text{DSB-SC}$ signals
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GATE ECE 1995 | Question 1.40
A $\text{PAM}$ signal can be detected by usingan $\text{ADC}$an integratora band pass filtera high pass filter
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GATE ECE 1995 | Question 1.41
A $1.0 \; \mathrm{kHz}$ signal is flat-top sampled at the rate of $1800$ samples sec and the samples are applied to an ideal rectangular $\text{LPF}$ with cat-off frequen...
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GATE ECE 1995 | Question 3.9
(A) $\text{AM}$ system(B) SSB system(C) PCM ( $n$ bit) system$2 B$ (Band width of the modulating signal)$2 \mathrm{~B}$Between $\text{B}$ and $\text{2B}$$2 n \mathrm{~B}$...
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GATE ECE 1996 | Question 1.17
The image channel rejection in a superheterodyne receiver comes from$\text{IF}$ stages only$\text{RF}$ stages onlydetector and $\text{RF}$ stages onlydetector $\text{RF}$...
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GATE ECE 1996 | Question 2.15
The number of bits in a binary $\mathrm{PCM}$ system is increased from $n$ to $n+1$. As a result, the signal to quantization noise ratio will improve by a factor$\frac{n+...
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GATE ECE 1996 | Question 2.17
An $\text{FM}$ signal with a modulation index $9$ is applied to a frequency tripler. The modulation index in the output signal will be$0$$3$$9$$27$
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GATE ECE 1996 | Question 2.18
The critical frequency of an ionospheric layer is $10 \; \mathrm{MHz}$. What is the maximum launching angle from the horizon for which $20 \; \mathrm{MHz}$ wave will be r...
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GATE ECE 1996 | Question 2.19
A $1 \mathrm{~km}$ long microwave link uses two antennas each having $30 \mathrm{~dB}$ gain. If the power transmitted by one antenna is $1 \mathrm{~W}$ at $3 \; \mathrm{G...
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GATE ECE 1996 | Question 3.4
(a) Capture effect is (b) Granular noise(c) Guard band isan $\text{AM}$ system a characteristics ofan $\text{FM}$ system occurs ina $\text{DM}$ system required ina $\text...
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GATE ECE 1996 | Question 3.5
(a) SSB Modulation(b) $\nabla \cdot \overline{\mathrm{B}}=0$(c) Model dispersionTransmission lineHilbert transformFaraday's lawAbsence of magnetic monopolesWaveguidesPhas...
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GATE ECE 2006 | Question: 20
A transmission line is feeding $1 \mathrm{Watt}$ of power to a horn antenna having a gain of $10 \mathrm{~dB}$. The antenna is matched to the transmission line. The total...
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GATE ECE 2006 | Question: 50
A signal $m(t)$ with bandwidth $500 \mathrm{~Hz}$ is first multiplied by a signal $g(t)$ where\[ g(t)=\sum_{\mathrm{R}=-\infty}^{\infty}(-1)^{k} \delta\left(t-0.5 \times ...
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GATE ECE 2006 | Question: 60
The minimum step-size required for a Delta-Modulator operating at $32 \mathrm{~K}$ samples/ $\mathrm{sec}$ to track the signal (here $u(t)$ is the unit-step function)$\be...
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GATE ECE 2006 | Question: 61
A zero- mean white Gaussian noise is passed through an ideal lowpass filter of ban width $10 \; \mathrm{kHz}$. The output is the uniformly sampled with sampling period $t...
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GATE ECE 2006 | Question: 63
The diagonal clipping in Amplitude Demodulation (using envelope detector) can be avoided if RC time-constant of the envelope detector satisfies the following condition, (...
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GATE ECE 2006 | Question: 65
A message signal with bandwidth $10 \; \mathrm{kHz}$ is Lower-Side Band SSB modulated with carrier frequency $f_{c 1}=10^{6} \mathrm{~Hz}$. The resulting signal is then p...
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GATE ECE 2006 | Question: 68
When a plane wave travelling in free-space is incident normally on a medium having $\varepsilon_{t}=4.0$, then fraction of power transmitted into the medium is given by$\...
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GATE ECE 2006 | Question: 75
Common Data for Questions 74, 75:Let $g(t)=p(t)^{*} p(t)$, where * denotes convolution and $p(t)=u(t)-u(t-1)$ with $u(t)$ being the unit step function An Amplitude Modul...
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GATE ECE 2006 | Question: 80
Statement for Linked Answer Questions 80 and 81Consider the following Amplitude Modulated (AM) signal, where $f_{m}<\mathrm{B}$\[x_{\mathrm{AM}}(t)=10\left(1+0.5 \sin 2 \...
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GATE ECE 2006 | Question: 81
Statement for Linked Answer Questions 80 and 81Consider the following Amplitude Modulated (AM) signal, where $f_{m}<\mathrm{B}$\[x_{\mathrm{AM}}(t)=10\left(1+0.5 \sin 2 \...
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GATE ECE 1994 | Question 1.14
$v(t)=5[\cos (106 \; \pi t)-\sin (103 \; \pi t) \times \sin (106 \; \pi t)$ represents$\text{DSB}$ suppressed carrier signal$\text{AM}$ signal$\text{SSB}$ upper sideband ...
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GATE ECE 1994 | Question 1.15
Increased pulse-width in the flat-top sampling, leads toattenuation of high frequencies in reproductionattenuation of low frequencies in reproductiongreater aliasing erro...
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GATE ECE 1994 | Question 1.16
Medium wave radio signals may be received at far off distances at night becauseradio waves travel faster at nightground wave attenuation is low at nightthe sky wave is st...
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GATE ECE 1994 | Question 1.17
For a short wave radio link between two stations via the ionosphere, the ratio of the maximum usable frequency to the critical frequencyis always less than $1$is always g...
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