Analog Filter Characteristics

Digital Communications Systems

This set of Digital Signal Processing aptitude tests focuses on “Characteristics of Commonly Used Analog Filters”.

1. Low pass Butterworth filters are also called as _____________
a) All-zero filter
b) All-pole filter
c) Pole-zero filter
d) None of the mentioned

2. What is the equation for magnitude square response of a low pass Butterworth filter?
a) 11+(ΩΩC)2N√
b) 1+(ΩΩC)2N
c) 1+(ΩΩC)2N−−−−−−−−−√
d) None of the mentioned

3. What is the transfer function of magnitude squared frequency response of the normalized low pass Butterworth filter?
a) 11+(s/j)−2N
b) 1+(sj)−2N
c) 1+(sj)2N
d) 11+(sj)2N

4. Which of the following is the band edge value of |H(Ω)|2?
a) (1+ε2)
b) (1-ε2)
c) 1/(1+ε2)
d) 1/(1-ε2)

5. The magnitude square response shown in the below figure is for which of the following given filters?

a) Butterworth
b) Chebyshev
c) Elliptical
d) None of the mentioned

6. What is the order of a low pass Butterworth filter that has a -3dB bandwidth of 500Hz and an attenuation of 40dB at 1000Hz?
a) 4
b) 5
c) 6
d) 7
.

7. Which of the following is true about type-1 chebyshev filter?
a) Equi-ripple behavior in pass band
b) Monotonic characteristic in stop band
c) Equi-ripple behavior in pass band & Monotonic characteristic in stop band
d) None of the mentioned

8. Type-2 chebyshev filters consists of ______________
a) Only poles
b) Both poles and zeros
c) Only zeros
d) Cannot be determined

9. Which of the following is false about the type-2 chebyshev filters?
a) Monotonic behavior in the pass band
b) Equi-ripple behavior in the stop band
c) Zero behavior
d) Monotonic behavior in the stop band
band.

10. The zeros of type-2 class of chebyshev filters lies on ___________
a) Imaginary axis
b) Real axis
c) Zero
d) Cannot be determined

11. Which of the following defines a chebyshev polynomial of order N, TN(x)?
a) cos(Ncos-1x) for all x
b) cosh(Ncosh-1x) for all x
c)

cos(Ncos-1x), |x|≤1
cosh(Ncosh-1x), |x|>1

d) None of the mentioned

12. The frequency response shown in the figure below belongs to which of the following filters?

a) Type-1 chebyshev
b) Type-2 chebyshev
c) Butterworth
d) Elliptical

13. What is the order of the type-2 chebyshev filter whose magnitude square response is as shown in the following figure?

a) 2
b) 4
c) 6
d) 3

14. Which of the following is true about the magnitude square response of an elliptical filter?
a) Equi-ripple in pass band
b) Equi-ripple in stop band
c) Equi-ripple in pass band and stop band
d) None of the mentioned

15. Bessel filters exhibit a linear phase response over the pass band of the filter.
a) True
b) False

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