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1
GATE2020EC: 8
The components in the circuit shown below are ideal. If the opamp is in positive feedback and the input voltage $V_{i}$ is a sine wave of amplitude $1$ $\text{V}$, the output voltage $V_{o}$ is a noninverted sine wave of $2$ $\text{V}$ amplitude. an inverted sine wave ... amplitude. a square wave of $5$ $\text{V}$ amplitude. a constant of either $+5$ $\text{V}$ or $5$ $\text{V}$.
asked
Feb 13
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jothee
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gate2020ec
communications
amplitude
0
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0
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2
GATE2020EC: 33
The base of an $\text{npn BJT T1}$ has a linear doping profile $N_{B}\left ( x \right )$ as shown below. The base of another $\text{npn BJT T2}$ has a uniform doping $N_{B}$ of $10^{17}cm^{3}$. All other parameters are identical for both the devices. ... $\text{T1}$. approximately $2.5$ times that of $\text{T1}$. approximately $0.7$ times that of $\text{T1}$.
asked
Feb 13
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by
jothee
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1.4k
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gate2020ec
communications
density
doping
0
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0
answers
3
GATE2020EC: 42
For the modulated signal $x\left ( t \right )=m\left ( t \right )\cos\left ( 2\pi f_{c}t \right )$, the message signal $m\left ( t \right )=4\cos\left ( 1000\pi t \right )$ and the carrier frequency $f_{c}$ is $1\: MHz$. The signal $x(t)$ is passed through a ... $\cos\left ( 920\pi t \right )$ $\cos\left ( 1000\pi t \right )$ $\cos\left ( 540\pi t \right )$
asked
Feb 13
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by
jothee
(
1.4k
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gate2020ec
communications
modulator
demodulator
0
votes
0
answers
4
GATE2020EC: 47
$S_{PM}(t)$ and $S_{FM}(t)$ as defined below, are the phase modulated and the frequency modlated waveforms, respectively, corresponding to the message signal $m(t)$ ... of $S_{PM}(t)$ and $S_{FM}(t)$ are same, then the value of the ratio $\dfrac{K_{p}}{K_{f}}$ is ________ seconds.
asked
Feb 13
in
Others
by
jothee
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1.4k
points)
gate2020ec
numericalanswers
communications
modulatedwaveforms
0
votes
0
answers
5
GATE2019 EC: 7
A linear Hamming code is used to map $4bit$ message to $7bit$ codewords. The encoder mapping is linear. If the message $0001$ is mapped to the codeword $0000111$, and the message $0011$ is mapped to the codeword $1100110$, then the message $0010$ is mapped to $0010011$ $1100001$ $1111000$ $1111111$
asked
Feb 12, 2019
in
Others
by
Arjun
(
1.4k
points)
gate2019ec
communications
hammingcodes
0
votes
0
answers
6
GATE2019 EC: 40
In the circuits shown the threshold voltage of each $\text{nMOS}$ transistor is $0.6\:V.$ Ignoring the effect of channel length modulation and body bias. the values of $\text{Vout}1$ and $\text{Vout} 2,$ respectively, in volts, are $1.8$ and $1.2$ $2.4$ and $2.4$ $1.8$ and $2.4$ $2.4$ and $1.2$
asked
Feb 12, 2019
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by
Arjun
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1.4k
points)
gate2019ec
communications
modulation
0
votes
0
answers
7
GATE2019 EC: 45
Let a random process $Y(t)$ be described as $Y(t)=h(t) \ast X(t)+Z(t),$ where $X(t)$ is a white noise process with power spectral density $S_{x}(f)=5$W/Hz. The filter $h(t)$ has a magnitude response given by $ \mid H(f) \mid =0.5$ ... , with power spectral density as shown in the figure. The power in $Y(t),$ in watts, is equal to _________ $W$ (rounded off to two decimal places).
asked
Feb 12, 2019
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by
Arjun
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1.4k
points)
gate2019ec
numericalanswers
communications
powerspectraldensity
0
votes
0
answers
8
GATE2019 EC: 46
A voice signal $m(t)$ is in the frequency range $5\:kHz$ to $15\:kHz$. The signal is amplitudemodulated to generated an AM signal $f(t)=A\left(1+m(t)\right)\cos 2\pi f_{c}t,$ where $f_{c}=600\: kHz.$ The AM signal $f(t)$ ... bits required for the encoding. The rate, in Megabits per second (rounded off to $2$ decimal places), of the resulting stream of coded bits is ________ Mbps.
asked
Feb 12, 2019
in
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by
Arjun
(
1.4k
points)
gate2019ec
numericalanswers
communications
0
votes
0
answers
9
GATE2019 EC: 55
In the circuit shown, $V_{1}=0$ and $V_{2}=V_{dd}.$ The other relevant parameters are mentioned in the figure. Ignoring the effect of channel length modulation and the body effect, the value of $I_{out}$ is _________ $mA$ (rounded off to $1$ decimal place).
asked
Feb 12, 2019
in
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by
Arjun
(
1.4k
points)
gate2019ec
numericalanswers
communications
modulations
0
votes
0
answers
10
GATE2016341
In the circuit shown in the figure , the channel length modulation of all transistors is nonzero $(\lambda\neq0)$. Also, all transistors operate in saturation and have negligible body effect .The ac small signal voltage gain ($V_o/V_{in}$ ... $g_{m1}(r_{o1}\mid\mid \left (\frac{1}{gm3}\mid\mid r_{o3})\mid\mid r_{o2} \right )$
asked
Mar 28, 2018
in
Others
by
Milicevic3306
(
15.7k
points)
gate2016ec3
communications
modulations
transistors
0
votes
0
answers
11
GATE2016342
In the circuit shown in the figure, transistor $M1$ is in saturation and has transconductance $g_m = 0.01$ siemens. Ignoring internal parasitic capacitances and assuming the channel length modulation $\lambda$ to be zero,the small signal input pole frequency (in $kHz$) is _________
asked
Mar 28, 2018
in
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by
Milicevic3306
(
15.7k
points)
gate2016ec3
numericalanswers
transconductance
modulations
communications
0
votes
0
answers
12
GATE2016249
An ideal bandpass channel $500 \: Hz –2000 \:Hz$ is deployed for communication. A modem is designed to transmit bits at the rate of $4800$ bits/s using $16QAM$. The rolloff factor of a pulse with a raised cosine spectrum that utilizes the entire frequency band is __________
asked
Mar 28, 2018
in
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by
Milicevic3306
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15.7k
points)
gate2016ec2
numericalanswers
communications
bandpassfilter
0
votes
0
answers
13
GATE2016250
Consider a random process $X\left ( t \right )=3V(t)8,$ where $V(t)$ is a zero mean stationary random process with autocorrelation $R_{v}\left ( \tau \right )=4e^{5\mid \tau \mid}.$ The power in $X(t)$ is _________
asked
Mar 28, 2018
in
Others
by
Milicevic3306
(
15.7k
points)
gate2016ec2
numericalanswers
communications
autocorrelation
0
votes
0
answers
14
GATE2016251
A binary communication system makes use of the symbols zero and one . There are channel errors. Consider the following events: ... information in bits that you obtain when you learn which symbol has been received (while you know that a zero has been transmitted) is _________
asked
Mar 28, 2018
in
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by
Milicevic3306
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15.7k
points)
gate2016ec2
numericalanswers
communications
0
votes
0
answers
15
GATE2016252
The parallelplate capacitor shown in the figure has movable plates. The capacitor is charged so that the energy stored in it is $E$ when the plate separation is $d$. The capacitor is then isolated electrically and the plate are moved such that the plate separation ... separation, what is the energy stored in the capacitor, neglecting fringing effects? $2E$ $\sqrt{2}E$ $E$ $E/2$
asked
Mar 28, 2018
in
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by
Milicevic3306
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15.7k
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gate2016ec2
communications
0
votes
0
answers
16
GATE2016121
Consider binary data transmission at a rate of $56$ kbps using baseband binary pulse amplitude modulation (PAM) that is designed to have a raisedcosine spectrum. The transmission bandwidth (in kHz) required for a rolloff factor of $0.25$ is ________
asked
Mar 28, 2018
in
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by
Milicevic3306
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15.7k
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gate2016ec1
numericalanswers
communications
modulation
0
votes
0
answers
17
GATE2016125
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
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by
Milicevic3306
(
15.7k
points)
gate2016ec1
communications
propagationconstant
0
votes
0
answers
18
GATE2015322
The modulation scheme commonly used for transmission from GSM mobile terminals is $4$QAM $16$PSK WalshHadamard orthogonal codes Gaussian Minimum Shift Keying (GMSK)
asked
Mar 28, 2018
in
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by
Milicevic3306
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15.7k
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gate2015ec3
communications
shiftkeying
0
votes
0
answers
19
GATE2015336
A three bit pseudo random number generator is shown. Initially the value of output $Y\equiv Y_{2} Y_{1} Y_{0}$ is set to $111.$ The value of output $Y$ after three clock cycles is $000$ $001$ $010$ $100$
asked
Mar 28, 2018
in
Others
by
Milicevic3306
(
15.7k
points)
gate2015ec3
communications
pseudorandomnumber
0
votes
0
answers
20
GATE2015150
The transmitted signal in a GSM system is of $200$ kHz bandwidth and $8$ users share a common bandwidth using TDMA. If at a given time $12$ users are talking in a cell, the total bandwidth of the signal received by the base station of the cell will be at least (in kHz) ___________.
asked
Mar 28, 2018
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by
Milicevic3306
(
15.7k
points)
gate2015ec1
numericalanswers
communications
tdma
0
votes
0
answers
21
GATE2014423
In a double sideband (DSB) full carrier AM transmission system, if the modulation index is doubled, then the ratio of total sideband power to the carrier power increases by a factor of __________.
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Mar 26, 2018
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by
Milicevic3306
(
15.7k
points)
gate2014ec4
numericalanswers
communications
amtransmission
0
votes
0
answers
22
GATE2014451
An Mlevel PSK modulation scheme is used to transmit independent binary digits over a bandpass channel with bandwidth $100$ kHz. The bit rate is $200$ kbps and the system characteristic is a raisedcosine spectrum with $100 \%$ excess bandwidth. The minimum value of M is __________
asked
Mar 26, 2018
in
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by
Milicevic3306
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15.7k
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gate2014ec4
numericalanswers
communications
frequencyshiftkeying
psk
0
votes
0
answers
23
GATE2014349
Let $X(t)$ be a wide sense stationary $(WSS)$ random process with power spectral density $S_{X}(f).$ If $Y(t)$ is the process defined as $Y(t)= X(2t1)$, the power spectral density $S_{Y}( f )$ is $S_{Y}( f )= \frac{1}{2}S_{X}\left ( \frac{f}{2} \right )e^{j\pi f}$ ... $S_{Y}( f )= \frac{1}{2}S_{X}\left ( \frac{f}{2} \right )e^{j2\pi f }$
asked
Mar 26, 2018
in
Others
by
Milicevic3306
(
15.7k
points)
gate2014ec3
randomprocess
communications
spectraldensity
0
votes
0
answers
24
GATE2014217
As FIR system is described by the system function $ H(z) = 1 + \frac{7}{2} z^{1} + \frac{3}{2}z^{2}$. The system is maximum phase minimum phase mixed phase zero phase
asked
Mar 26, 2018
in
Others
by
Milicevic3306
(
15.7k
points)
gate2014ec2
digitalcircuits
continuoustimesignals
communications
0
votes
0
answers
25
GATE2014223
Consider sinusoidal modulation in an AM system. Assuming no overmodulation, the modulation index ($\mu$) when the maximum and minimum values of the envelope, respectively, are $3$ V and $1$ V, is ___________.
asked
Mar 26, 2018
in
Others
by
Milicevic3306
(
15.7k
points)
gate2014ec2
numericalanswers
communications
networksolutionmethods
0
votes
0
answers
26
GATE2014240
In the circuit shown, choose the correct timing diagram of the output (y) from the given waveforms $W1$, $W2$, $W3$ and $W4$. $W1$ $W2$ $W3$ $W4$
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Mar 26, 2018
in
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by
Milicevic3306
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15.7k
points)
gate2014ec2
communications
timingdiagram
0
votes
0
answers
27
GATE2014244
The inputoutput relationship of a causal stable LTI system is given as $y[n] = \alpha \: y[n1] + \beta \: x[n]$. If the impulse response $h[n]$ of this system satisfies the condition $\sum_{n=0}^{\infty}h[n]= 2$, the relationship between $\alpha$ and $\beta$ is $\alpha = 1\beta /2$ $\alpha = 1+\beta /2$ $\alpha = 2\beta$ $\alpha = 2\beta$
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Mar 26, 2018
in
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by
Milicevic3306
(
15.7k
points)
gate2014ec2
communications
ltisystems
0
votes
0
answers
28
GATE2014250
Coherent orthogonal binary FSK modulation is used to transmit two equiprobable symbol waveforms $s_{1}( t )= \alpha \cos 2\pi f_1 t$, and $s_2(t) = \alpha \cos 2 \pi f_2 t$ where $\alpha = 4$ ... the bit error probability for a data rate of $500$ kbps is $Q(2)$ $Q(2\sqrt{2})$ $Q(4)$ $Q(4\sqrt{2})$
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Mar 26, 2018
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Milicevic3306
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15.7k
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gate2014ec2
communications
fsk
0
votes
0
answers
29
GATE2014251
The power spectral density of a real stationary random process $X(t)$ is given by $ S_X (f) = \begin{cases} \frac{1}{W}, & \mid f \mid \leq W \\ 0, & \mid f \mid > W \end{cases}$ The value of the expectation $E \left [ \pi X(t)X\left ( t\frac{1}{4W} \right ) \right ]$ is __________.
asked
Mar 26, 2018
in
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by
Milicevic3306
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15.7k
points)
gate2014ec2
numericalanswers
communications
powerspectraldensity
0
votes
0
answers
30
GATE2014252
In the figure, $M(f)$ is the Fourier transform of the message signal $m(t)$ where $A = 100$ Hz and $B = 40$ Hz. Given $v(t)= \cos (2\pi f_{c}t)$ and $w(t)= \cos (2\pi (f_{c}+A)t)$, where $f_{c}>A$. The cutoff frequencies of both the filters are $f_{c}$. The bandwidth of the signal at the output of the modulater (in Hz) is ______.
asked
Mar 26, 2018
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by
Milicevic3306
(
15.7k
points)
gate2014ec2
numericalanswers
communications
0
votes
0
answers
31
GATE2014151
Let $Q(\sqrt{\gamma})$ be the BER of a BPSK system over an AWGN channel with twosided noise power spectral density $N_{0}/2.$ The parameter $\gamma$ is a function of bit energy and noise power spectral density. A system with two independent and identical AWGN channels with ... of both the channels. If the BER of this system is $Q( b \sqrt{\gamma})$ then the value of $b$ is _____.
asked
Mar 26, 2018
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Milicevic3306
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15.7k
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gate2014ec1
numericalanswers
communications
digitalmodulation
0
votes
0
answers
32
GATE201239
The signal $m(t)$ as shown is applied both to a phase modulator (with $k_p$ as the phase constant) and a frequency modulator (with $k_f$ as the frequency constant) having the same carrier frequency. The ratio $\frac{k_p}{k_f}$ (in $rad/Hz$) for the same maximum phase deviation is $8\pi$ $4\pi$ $2\pi$ $\pi$
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Mar 25, 2018
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Others
by
Milicevic3306
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15.7k
points)
gate2012ec
communications
0
votes
0
answers
33
GATE201227
A BPSK scheme operating over an AWGN channel with noise power spectral density of $\frac{N_o}{2}$, uses equiprobable signals $s_1(t)=\sqrt{\frac{2E}{T}}\sin(\omega_ct)$ and $s_2(t)=\sqrt{\frac{2E}{T}}\sin(\omega_ct)$ over the symbol interval $(0,T)$. If the local oscillator in a ... $Q(\sqrt{\frac{E}{N_o}})$ $Q(\sqrt{\frac{E}{2N_o}})$ $Q(\sqrt{\frac{E}{4N_o}})$
asked
Mar 25, 2018
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Others
by
Milicevic3306
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15.7k
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gate2012ec
communications
0
votes
0
answers
34
GATE20122
The power spectral density of a real process $X(t)$ for positive frequencies is shown below. The values of $E[X^2(t)]$ and $ \mid E[X(t)] \mid$, respectively, are $\frac{6000}{\pi}\:,\:0$ $\frac{6400}{\pi}\:,\:0$ $\frac{6400}{\pi}\:,\:\frac{20}{(\pi\sqrt2)}$ $\frac{6000}{\pi}\:,\:\frac{20}{(\pi\sqrt2)}$
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Mar 25, 2018
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by
Milicevic3306
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15.7k
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gate2012ec
communications
spectraldensity
0
votes
0
answers
35
GATE201828
Consider a white Gaussian noise process $\text{N(t)}$ with twosided power spectral density $S_{N}\left ( f \right )=0.5\:W/Hz$ as input to a filter with impulse response $0.5e^{t^{2}/2}$ (where $t$ is in seconds) resulting in output $Y(t)$. The power in $Y(t)$ in watts is $0.11$ $0.22$ $0.33$ $0.44$
asked
Feb 19, 2018
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by
gatecse
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1.4k
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gate2018ec
gaussiannoise
powerspectraldensity
communications
0
votes
0
answers
36
GATE201827
Let $c\left ( t \right )=A_{c} \cos \left ( 2\pi f_{c}t\right )$ and $m\left ( t \right )=\cos \left ( 2\pi f_{m}t\right )$. It is given that $f_{c}>> 5f_{m}.$ The signal $c\left ( t \right )+m\left ( t \right )$ is applied to the input of a ... (AM) wave. If it is desired to have the sideband power of the AM wave to be half of the carrier power, then $a/b$ is $0.25$ $0.5$ $1$ $2$
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Feb 19, 2018
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gate2018ec
communications
amwave
0
votes
0
answers
37
GATE201816
Consider a binary channel code in which each codeword has a fixed length of $5\: bits$. The Hamming distance between any pair of distinct codewords in this code is at least $2$. The maximum number of codewords such a code can contain is __________.
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Feb 19, 2018
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gatecse
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1.4k
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gate2018ec
numericalanswers
communications
hammingdistance
0
votes
0
answers
38
GATE2017 EC2: 52
Consider a binary memoryless channel characterized by the transition probability diagram shown in the figure. The channel is lossless noiseless useless deterministic
asked
Nov 25, 2017
in
Communications
by
admin
(
2.8k
points)
gate2017ec2
informationtheory
communications
0
votes
0
answers
39
GATE2017 EC2: 51
A modulating signal given by $x(t)=5\sin (4\pi 10^3t 10\pi \cos 2\pi 10^3t)V$ is fed to a phase modulator with phase deviation constant $k_p=5$ rad/V. If the carrier frequency is $20$ kHz, the instantaneous frequency(in kHz) at $t=0.5$ ms is ____________
asked
Nov 25, 2017
in
Communications
by
admin
(
2.8k
points)
gate2017ec2
analogcommunications
numericalanswers
communications
0
votes
0
answers
40
GATE2017 EC2: 50
The unmodulated carrier power in an AM transmitter is $5$ kW. This carrier is modulated by a sinusoidal modulating signal. The maximum percentage of modulation is $50 \%$. If it is reduced to $40 \%$, then the maximum unmodulated carrier power (in kW) that can be used without overloading the transmitter is _________
asked
Nov 25, 2017
in
Communications
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admin
(
2.8k
points)
gate2017ec2
ammodulation
numericalanswers
communications
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