This set of Digital Signal Processing Multiple Choice Questions & Answers (MCQs) focuses on “Design of IIR Filters from Analog Filters”.

1. What is the duration of the unit sample response of a digital filter?

a) Finite**b) Infinite**

c) Impulse(very small)

d) Zero

2. Which of the following methods are used to convert analog filter into digital filter?

a) Approximation of Derivatives

b) Bilinear transformation

c) Impulse invariance**d) All of the mentioned**

3. Which of the following is the difference equation of the FIR filter of length M, input x(n) and output y(n)?

a) y(n)=∑M+1k=0bkx(n+k)

b) y(n)=∑M+1k=0bkx(n−k)**c) y(n)=∑M−1k=0bkx(n−k)**

d) None of the mentioned

4. What is the relation between h(t) and H_{a}(s)?**a) H _{a}(s)=∫∞−∞h(t)e−stdt**

b) H

_{a}(s)=∫∞0h(t)estdt

c) H

_{a}(s)=∫∞−∞h(t)estdt

d) None of the mentioned

5. Which of the following is a representation of system function?

a) Normal system function

b) Laplace transform

c) Rational system function**d) All of the mentioned**

6. For an analog LTI system to be stable, where should the poles of system function H(s) lie?

a) Right half of s-plane**b) Left half of s-plane**

c) On the imaginary axis

d) At origin

7. If the conversion technique is to be effective, the jΩ axis in the s-plane should map into the unit circle in the z-plane.**a) True**

b) False

**c) Inside unit circle**

8. If the conversion technique is to be effective, then the LHP of s-plane should be mapped into _____________

a) Outside of unit circle

b) Unit circle**c) Inside unit circle**

d) Does not matter

9. Physically realizable and stable IIR filters cannot have linear phase.**a) True**

b) False

10. What is the condition on the system function of a linear phase filter?

a) H(z)=z−NH(z−1)

b) H(z)=zNH(z−1)

c) H(z)=±zNH(z−1)**d) H(z)=±z−NH(z−1)**

11. If the filter is in linear phase, then filter would have a mirror-image pole outside the unit circle for every pole inside the unit circle.**a) True**

b) False

12. What is the order of operations to be performed in order to realize linear phase IIR filter?

(i) Passing x(-n) through a digital filter H(z)

(ii) Time reversing the output of H(z)

(iii) Time reversal of the input signal x(n)

(iv) Passing the result through H(z)

a) (i),(ii),(iii),(iv)**b) (iii),(i),(ii),(iv)**

c) (ii),(iii),(iv),(i)

d) (i),(iii),(iv),(ii)

13. When an application requires a linear phase filter, it should be an FIR filter.**a) True**

b) False