Recent questions tagged discrete-time-signals

In the figure is a linear time invariant discrete systme is shown. Blocks labelled $D$ represent unit delay elements. For $n<0$, you may assume that $x$ (n), $y_{1}(n), y...

The $z$-transform $\mathrm{F}(z)$ of the function $f(n \mathrm{T})=a^{\prime \prime T}$ is$\frac{z}{z-a^{\mathrm{T}}}$$\frac{z}{z+a^{\mathrm{T}}}$$\frac{\mathrm{z}}{\math...

The $z$-transform of a signal is given by\[C(z)=\frac{1 z^{-1}\left(1-z^{-4}\right)}{4\left(1-z^{-1}\right)^{2}}\]Its final value is$1 / 4$zero$1.0$infinity

The region of convergence of the $z$-transform of a unit step function is$|z|>1$$|z|<1$(Real part of $z)>0$( Real part of $z)<0$

If the impulse response of a discrete-time system is $h[n]=-5^{n} u[-n-1]$, then the system function $\mathrm{H}(z)$ is equal to$\frac{-z}{z-5}$ and the system is stable$...

If the variance $\sigma_{x}^{2}$ of $d(n)=x(n)-x(n-1)$ is one-tenth the variance $\sigma_{x}^{2}$ of a stationary zero-mean discrete-time signal $x(n)$, then the normaliz...

The $Z$-transform of the time function $\sum_{k=0}^{\infty} \delta(n-k)$ is$\frac{Z-1}{Z}$$\frac{Z}{Z-1}$$\frac{Z}{(Z-1)^2}$$\frac{(Z-1)^2}{Z}$

A sequence $x(n)$ with the z-transform $X(z)=z^4+z^2-2 z+2-3 z-4$ is applied as an input to a linear, time-invariant system with the impulse response $h(n)=2 \delta(n-3)$...

Let $\mathrm{P}$ be linearity, $\mathrm{Q}$ be time-invariance, $\mathrm{R}$ be causality and $\mathrm{S}$ be stability. A discrete-time system has the input-output relat...

The impulse response $h[n]$ of a linear time-invariant system is given by\[h[n]=u[n+3]+u[n-2]-2 u[n-7]\]where $u[n]$ is the unit step sequence. The above system isstable ...

The $z$-transform of a system is $H(z)=\frac{z}{z-0.2}.$ If the ROC is $|z|<0.2$, then the impulse response of the system is$(0.2)^{n} u[n]$$(0.2)^{n} u[-n-1]$$-(0.2)^{n}...

Consider the sequence $x[n]=\left[\begin{array}{lll}-4- \uparrow{j} 5 & 1+j 2 & 4\end{array}\right]$The conjugate anti-symmetric part of the sequence is$[-4-j 2.5 \quad j...

A causal $\text{LTI}$ system is described by the difference equation\[2 y[n]=\alpha y[n-2]-2 x[n]+\beta x[n-1]\]The system is stable only if$|\alpha|=2, \quad|\beta|<2$$|...

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...

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...

Let $x(n)=\left(\frac{1}{2}\right)^{n} u(n), y(n)=x^{2}(n)$ and $\mathrm{Y}\left(e^{j i e}\right)$ be the Fourier transform of $y(n)$. Then $Y\left(e^{j i e}\right)$ is$\...

Match the following and choose the correct combination.$$\begin{array}{ll} \qquad \qquad \quad \textbf{Group 1} & \quad \qquad \qquad \qquad \qquad \textbf{Group 2} \\ \t...

Statement of Linked Answer Questions 85a and 85bA sequence $x(n)$ has non-zero values as shown in the figureThe sequence $y(n)=\left\{x\left(\frac{n}{2}-1\right)\right.$ ...

If the region of convergence of $x_1[n]+x_2[n]$ is $\frac{1}{3}<|z|<\frac{2}{3}$, then the region of convergence of $x_1[n]-x_2[n]$ includes $\frac{1}{3}<|z|<3$$\frac{2}{...

A system with input $x[n]$ and output $y[n]$ is given as $y[n]=\left(\sin \frac{5}{6} \pi n\right) x(n)$.The system islinear, stable and invertiblenon-linear, stable and ...

A $5$-point sequence $x[n]$ is given as\[ x[-3]=1, \quad x[-2]=1, \quad x[-1]=0, \quad x[0]=5, \quad x =1 .\]Let $X\left(e^{j \omega}\right)$ denote the discrete-time Fou...

The $z$-transform $X[z]$ of a sequence $x[n]$ is given by $X[z]=\dfrac{0.5}{1-2 z^{-1}}$. It is given that the region of convergence of $X[z]$ includes the unit circle. T...

A discrete time linear shift-invariant system has an impulse response $h[n]$ with $h[0]=1, h =-1$, $h =2$, and zero otherwise. The system is given an input sequence $x[n]...

$\{x(n)\}$ is a real-valued periodic sequence with a period N. $x(n)$ and $X(k)$ form $\mathrm{N}$-point Discrete Fourier Transform (DFT) pairs. The DFT $Y(k)$ of the seq...

In the following network, the switch is closed at $t=0$ - and the sampling starts from $t=0$. The sampling frequency is $10 \mathrm{~Hz}$.The expression and the region of...

The $\text{ROC}$ of $\text{Z}$-transform of the discrete time sequence $\quad x(n)=\left(\dfrac{1}{3}\right)^{n} u(n)-\left(\dfrac{1}{2}\right)^{n} u(-n-1) \quad$ is$\fra...

A system with transfer function $H(z)$ has impulse response $h(\cdot)$ defined as $h(2)=1, h(3)=-1$ and $h(k)=0$ otherwise. Consider the following statements.$\qquad \qqu...

Consider the $z$-transform $X(z)=5 z^2+4 z^{-1}+3 ; 0<|z|<\infty$. The inverse $z$-transform $x[n]$ is$5\; \delta[n+2]+3\; \delta[n]+4\; \delta[n-1]$$5\; \delta[n-2]+3\; ...

For an $\mathrm{N}$-point $\mathrm{FFT}$ algorithm with $\mathrm{N}=2^{\text {m}}$, which one of the following statements is $\text{TRUE}?$It is not possible to construct...