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Multirate digital signal processing MCQs 1. What is the process of converting a signal from a given rate to a different rate? a) Sampling b) Normalizing c) Sampling rate conversion d) None of the mentioned 2. There is no requirement to process the various signals at different rates commensurate with the corresponding bandwidths of the signals. a) True b) False 3. The systems that employ multiple sampling rates are called multi-rate DSP systems. a) True b) False 4. Which of the following methods are used in sampling rate conversion of a digital signal? a) D/A convertor and A/D convertor b) Performing entirely in digital domain c) None of the mentioned d) D/A convertor, A/D convertor & Performing entirely in digital domain 5. Which of the following is the advantage of sampling rate conversion by converting the signal into analog signal? a) Less signal distortion b) Quantization effects c) New sampling rate can be arbitrarily selected d) None of the mentioned 6. In which of the following, sampling rate conversion are used? a) Narrow band filters b) Digital filter banks c) Quadrature mirror filters d) All of the mentioned 7. Which of the following is the disadvantage of sampling rate conversion by converting the signal into analog signal? a) Signal distortion b) Quantization effects c) New sampling rate can be arbitrarily selected d) Signal distortion & Quantization effects 8. Which of the following use quadrature mirror filters? a) Sub band coding b) Trans-multiplexer

c) Sub band coding & Trans-multiplexer d) None of the mentioned 9. The sampling rate conversion can be as shown in the figure below

a) True b) False 10. If Fx and Fy are the sampling rates of the input and output signals respectively, then what is the value of Fy/Fx? a) D/I b) I/D c) I.D d) None of the mentioned 11. What is the process of reducing the sampling rate by a factor D? a) Sampling rate conversion b) Interpolation c) Decimation d) None of the mentioned 12. What is the process of increasing the sampling rate by a factor I? a) Sampling rate conversion b) Interpolation c) Decimation d) None of the mentioned 13. What is the folding frequency for the aliased version of x(n) with sampling rate F? a) F/D b) F/4D c) F/2 d) F/2D 14. To what value should the bandwidth of x(n) has to be reduced in order to avoid aliasing? a) F/D b) F/2D c) F/4D d) None of the mentioned 15. Which process has a block diagram as shown in the figure below?

a) Sampling rate conversion b) Interpolation c) Decimation d) None of the mentioned 16. Which of the following is true about the filtering operation on x(n)? a) Linear b) Time variant c) None of the mentioned d) Linear and time invariant 17. . If HD(ω) is the frequency response of the low pass filter, then for what value of ω, HD(ω)=1? a) |ω| = π/D b) |ω| ≥ π/D c) |ω| ≤ π/D d) None of the mentioned 18. The filter eliminates the spectrum of X(ω) in the range π/D < ω < π. a) True b) False 19. If we down-sample a signal x(n), then the resulting signal will be an aliased version of x(n). a) True b) False 20. The linear filtering operation followed by down sampling on x(n) is not time invariant. a) True b) False

FIR filter Design MCQs 1. 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 2. The lower and upper limits on the convolution sum reflect the causality and finite duration characteristics of the filter. a) True b) False 3. Which of the following condition should the unit sample response of a FIR filter satisfy to have a linear phase? a) h(M-1-n) n=0,1,2…M-1 b) ±h(M-1-n) n=0,1,2…M-1 c) -h(M-1-n) n=0,1,2…M-1 d) None of the mentioned 4. If H(z) is the z-transform of the impulse response of an FIR filter, then which of the following relation is true? a) zM+1.H(z-1)=±H(z) b) z-(M+1).H(z-1)=±H(z) c) z(M-1).H(z-1)=±H(z) d) z-(M-1).H(z-1)=±H(z) 5. The roots of the polynomial H(z) are identical to the roots of the polynomial H(z-1). a) True b) False 6. The roots of the equation H(z) must occur in ________________ a) Identical b) Zero c) Reciprocal pairs d) Conjugate pairs 7. If the unit sample response h(n) of the filter is real, complex valued roots need not occur in complex conjugate pairs. a) True b) False 8. What is the value of h(M-1/2) if the unit sample response is anti-symmetric? a) 0 b) 1

c) -1 d) None of the mentioned 9. What is the number of filter coefficients that specify the frequency response for h(n) symmetric? a) (M-1)/2 when M is odd and M/2 when M is even b) (M-1)/2 when M is even and M/2 when M is odd c) (M+1)/2 when M is even and M/2 when M is odd d) (M+1)/2 when M is odd and M/2 when M is even 10. What is the number of filter coefficients that specify the frequency response for h(n) anti-symmetric? a) (M-1)/2 when M is even and M/2 when M is odd b) (M-1)/2 when M is odd and M/2 when M is even c) (M+1)/2 when M is even and M/2 when M is odd d) (M+1)/2 when M is odd and M/2 when M is even 11. Which of the following is not suitable either as low pass or a high pass filter? a) h(n) symmetric and M odd b) h(n) symmetric and M even c) h(n) anti-symmetric and M odd d) h(n) anti-symmetric and M even 12. The anti-symmetric condition with M even is not used in the design of which of the following linear-phase FIR filter? a) Low pass b) High pass c) Band pass d) Bans stop 13. The anti-symmetric condition is not used in the design of low pass linear phase FIR filter. a) True b) False 14. Which of the following defines the rectangular window function of length M-1? a) w(n)=1, n=0,1,2...M-1 =0,elsewhere b) w(n)=1, n=0,1,2...M-1 =-1,elsewhere c) w(n)=0, n=0,1,2...M-1 =1, else where d) None of the mentioned 15. The multiplication of the window function w(n) with h(n) is equivalent to the multiplication of H(w) and W(w). a) True b) False

16. What is the Fourier transform of the rectangular window of length M-1?

ans 17. What is the magnitude response |W(ω)| of a rectangular window function? a) |sin(ωM/2)|/|sin(ω/2)| b) |sin(ω/2)|/|sin(ωM/2)| c) |cos(ωM/2)|/|sin(ω/2)| d) None of the mentioned 18. What is the width of the main lobe of the frequency response of a rectangular window of length M-1? a) π/M b) 2π/M c) 4π/M d) 8π/M 19. The width of each side lobes decreases with an increase in M. a) True b) False 20. With an increase in the value of M, the height of each side lobe ____ a) Do not vary b) Does not depend on value of M c) Decreases d) Increases 21. As M is increased, W(ω) becomes wider and the smoothening produced by the W(ω) is increased. a) True b) False 22. Which of the following windows has a time domain sequence h(n)=1− M −1 ] 2 M −1 a) Bartlett window b) Blackman window 2 [n−

c) Hanning window d) Hamming window 23. The width of each side lobes decreases with an decrease in M. a) True b) False 24. What is the approximate transition width of main lobe of a Hamming window? a) 4π/M b) 8π/M c) 12π/M d) 2π/M 25. What is the peak side lobe (in dB) for a rectangular window? a) -13 b) -27 c) -32 d) -58 26. What is the peak side lobe (in dB) for a Hanning window? a) -13 b) -27 c) -32 d) -58 27. How does the frequency of oscillations in the pass band of a low pass filter varies with the value of M? a) Decrease with increase in M b) Increase with increase in M c) Remains constant with increase in M d) None of the mentioned 28. The oscillatory behavior near the band edge of the low pass filter is known as Gibbs phenomenon. a) True b) False 29. Which of the following window is used in the design of a low pass filter to have a frequency response as shown in the figure?

a) Hamming window b) Hanning window

c) Kaiser window d) Blackman window 30. Which of the following window is used in the design of a low pass filter to have a frequency response as shown in the figure?

a) Hamming window b) Hanning window c) Kaiser window d) Blackman window 31. What is the approximate transition width of main lobe of a Blackman window? a) 4π/M b) 8π/M c) 12π/M d) 2π/M 32. If the value of M increases then the main lobe in the frequency response of the rectangular window becomes broader. a) True b) False 33. The large side lobes of W(ω) results in which of the following undesirable effects? a) Circling effects b) Broadening effects c) Ringing effects d) None of the mentioned

34. Which of the following windows has a time domain sequence h(n)=0.5(1−cos2πn/M−1)? a) Bartlett window b) Blackman window c) Hamming window d) Hanning window...