Recent questions without answers

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961
A causal system having the transfer function $\mathrm{H}(s)=\frac{1}{s+2}$ is excited with $10 u(t)$. The time at which the output reaches $99 \%$ of its steady state val...
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962
The impulse response $h|n|$ of a linear time invariant system is given as\[h[n]=\left\{\begin{array}{cc}-2 \sqrt{2} & n=1,-1 \\4 \sqrt{2} & n=2,-2 \\0, & \text { otherwis...
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963
Let $x(t)$ and $y(t)$ (with Fourier transforms $X(f)$ and $Y(f)$ respectively) be related as shown in the given figure.Then $Y(f)$ is$-\frac{1}{2} X(f / 2) e^{-j 2 \pi f}...
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964
A system has poles at $0.01 \mathrm{~Hz}, 1 \mathrm{~Hz}$ and $80 \mathrm{~Hz}$; zeros at $5 \mathrm{~Hz}, 100 \mathrm{~Hz}$ and $200 \mathrm{~Hz}$. The approximate phase...
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965
Consider the signal flow graph shown in the figure below. The gain $\frac{x_{5}}{x_{1}}$ is$\frac{1-\left(b e+c f+d g\right)}{a b c}$$\frac{b e d g}{1-(b e+c f+d g)}$$\fr...
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966
If $A=\left[\begin{array}{cc}-2 & 2 \\ 1 & -3\end{array}\right]$, then $\sin A t$ is$\frac{1}{3}\left[\begin{array}{cc}\sin (-4 t)+2 \sin (-t) & -2 \sin (-4 t)+2 \sin (-t...
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967
The open-loop transfer function of a unity feedback system is $G(s)=\frac{K}{s\left(s^{2}+s+2\right)(s+3)}$The range of $\mathrm{K}$ for which the system is stable is$\fr...
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968
For the polynomial $P(s)=s^{5}+s^{4}+2 s^{3}+2 s^{2}+3 s+15$, the number of roots which lie in the right half of the s-plane is$4$$2$$3$$1$
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969
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970
Given $A=\left[\begin{array}{ll}1 & 0 \\ 0 & 1\end{array}\right]$, the state transition matrix $e^{A t}$ is given by$\left[\begin{array}{cc}0 & e^{-t} \\ e^{-t} & 0\end{a...
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973
A $100 \; \mathrm{MHz}$ carrier of $1 \mathrm{~V}$ amplitude and a $1 \; \mathrm{MHz}$ modulating signal of $1 \mathrm{~V}$ amplitude are fed to a balanced modulator. The...
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974
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976
A random variable $\mathrm{X}$ with uniform density in the interval $0$ to $1$ is quantized as follows:$\begin{array}{ll} \qquad \text{If 0 < X < 0.3,} & \text{x}_{4} = 0...
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977
Choose the correct one from among the alternatives $\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D}$ after matching an item from Group $1$ with the most appropriate item i...
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980
A parallel plate air-filled capacitor has plate area of $10^{-1} \mathrm{~m}^{2}$ and plate separation of $10^{-3} \mathrm{~m}$. It is connected to a $0.5 \mathrm{~V}, 3....
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983
In a microwave test bench, why is the microwave signal amplitude modulated at $1 \; \mathrm{kHz}$?To increase the sensitivity of measurementTo transmit the signal to a fa...
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985
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987
A lossless transmission line is terminated in a load which reflects a part of the incident power. The measured VSWR is $2.$ The percentage of the power that is reflected ...
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988
(A) $\text{AM}$ system(B) $\text{DSB-SC}$ system(C) $\text{PAM}$ systemCoherent detectionEnvelope detectionCorrelation detection$\text{PLL}$$\text{LPF}$
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989
The following differential equation has\[3 \frac{d^{2} y}{d t^{2}}+4\left(\frac{d y}{d t}\right)^{3}+y^{2}+2=x\]degree $=2$, order $=1$degree $=3$, order $=2$degree $=4$,...
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990
Choose the function $f(t); – \infty < 1 < \infty,$ for which a Fourier series cannot be defined.$3 \sin (25 t)$$4 \cos (20 t+3)+2 \sin (710 t)$$\exp (-|t|) \sin (25 t)$...
1 votes
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991
A fair dice is rolled twice. The probability that an odd number will follow an even number is$\frac{1}{2}$$\frac{1}{6}$$\frac{1}{3}$$\frac{1}{4}$
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992
A solution of the following differential equation is given by\[\frac{d^{2} y}{d x^{2}}-5 \frac{d y}{d x}+6 y=0\]$y=e^{2 x}+e^{-3 x}$$y=e^{2 x}+e^{3 x}$$y=e^{-2 x}+e^{3 x}...
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993
The function $x(t)$ is shown in the figure. Even and odd parts of a unit-step function $u(t)$ are respectively,$\frac{1}{2}, \frac{1}{2} x(t)$$-\frac{1}{2}, \frac{1}{2} x...
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994
The region of convergence of $Z$-transform of the sequence$\left(\frac{5}{6}\right)^{n} u(n)-\left(\frac{6}{5}\right)^{n} u(-n-1)$ must be$|z|<\frac{5}{6}$$|z|>\frac{6}{5...
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996
The $\text{ABCD}$ parameters of an ideal $n: 1$ transformer shown in the figure are $\left[\begin{array}{ll}n & 0 \\ 0 & \mathrm{X}\end{array}\right]$. The value of $X$ w...
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997
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998
The maximum power that can be transferred to the load resistor $R_{L}$ from the voltage source in the figure is$1 \mathrm{~W}$$10 \mathrm{~W}$$0.25 \mathrm{~W}$$0.5 \math...
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999
The bandgap of Silicon at room temperature is$1.3 \; \mathrm{eV}$$0.7 \; \mathrm{eV}$$1.1 \; \mathrm{eV}$$1.4 \; \mathrm{eV}$
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1000