B.TECH - Semester 6 digital signal processing Question Paper 2020 (sep)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Distinguish between energy and power of a signal.
- Explain the significance of impulse response.
- Consider the discrete time system $y(n)=n x(n)$ Determine whether the system time variant or time invariant. Defend your answer.
- Give an example each for linear and non linear system.
- State Parseval's theorem for DFT.
- State convolution theorem for $Z$ transform.
- Find the $z$-transform of the causal sequence $x(n)=[1,0,3,-1,2]$.
- Sketch the block diagram representation of the system $$ y(n)=\operatorname{box}(n)+b_{1} x(n-1)+b_{2} x(n-2) $$
- Sketch the block diagram representation of second order system.
- Name the different filter structure for IIR system. ( $\mathbf{1 0} \boldsymbol{\times} \mathbf{4} \boldsymbol{=} \mathbf{4 0}$ Marks) Answer any one questions from each Module. Each question carries 20 marks.
- When do you say a system is (a) Memory less
- When do you say a system is (b) Time invariant
- When do you say a system is (c) Linear
- When do you say a system is (d) Causal. Determine which of these properties hold and which do not hold for each of the following discrete time systems. Justify your answer
- When do you say a system is (i) $y(n)=x(n)+\frac{1}{x(n-1)}$ (ii) $y(n)=x^{2}(n)$ (iii) $y(n)=n x(n)$.
- Describe the steps for calculation of convolution sum. Calculate the convolution sum of two sequences $x(n)=\{1,2,1,1\} h(n)=\{1,-1,1,-1\}$.
- State and prove any three properties of $z$ transform.
- Find the inverse $z$ transform ofs (a) $\quad x(z)=\frac{1}{2 z^{-2}+2 z^{-1}+1}$
- Find the inverse $z$ transform ofs (b) $\quad x(z)=\frac{1+3 z^{-1}}{1+3 z^{-1}+2 z^{-2}}$.
- Explain different structures of FIR filters.
- (a) For IIR system $H(z)=\frac{z^{-1}}{1+z^{-1}+\frac{1}{z} z^{-2}}$ sketch the direct form realization.
- (b) Sketch the direct form realization of FIR system with $H(z)=\sum_{k=0}^{n-1} h(k) z^{-k}$ and $y(n)=\sum_{k=0}^{n-1} h(k) x(n-k)$. $$ (3 \times 20=60 \text { Marks }) $$