Digital Signal Processing Online Test

1. The effect of round off errors due to the multiplications performed in the DFT with fixed point arithmetic is known as Quantization error.

2. If the frequency response of an FIR system is given as H(z)=1-5/2z^-1-3/2z^-2, then the system is ___________

3. What is the impulse response of an S/H, when viewed as a linear filter?

4. Which of the following relation is true if the signal x(n) is real?

5. Bessel filters exhibit a linear phase response over the pass band of the filter.

6. Which of the following filters have a block diagram as shown in the figure?

7. What is the convolution x(n) of the signals x₁(n)={1,-2,1} and x₂(n)={1,1,1,1,1,1}?

8. Which of the following is true regarding the number of computations requires to compute an N-point DFT?

9. If we reverse the directions of all branch transmittances and interchange the input and output in the flow graph, then the resulting structure is called as ______________

10. What is the average power of the discrete time periodic signal x(n) with period N?

11. If a signal x(n) is passed through a system to get an output signal of y(n)=x(n+1), then the signal is said to be ____________

12. Let x₁(t) and x₂(t) be periodic signals with fundamental periods T₁ and T₂ respectively. Then the fundamental period of x(t)=x₁(t)+x₂(t) is?

13. Limit cycles in the recursive are directly attributable to which of the following?

14. If X(z) is the z-transform of the signal x(n), then what is the z-transform of x*(n)?

15. Which of the following is the right way to reduce distortion in the DM?

16. What is the partial fraction expansion of X(z)=\(\frac{1+z^{-1}}{1-z^{-1}+0.5z^{-2}}\)?

17. The error function E(ω) does not alternate in sign between two successive extremal frequencies.

18. Which of the following is a low pass-to-band stop transformation?

19. It is impossible to design an all-pass digital Hilbert transformer.

20. By impulse invariance method, the IIR filter will have a unit sample response h(n) that is the sampled version of the analog filter.

21. The choice of T_d(ω_k) for error in delay is complicated.

22. What is the zero-input response of the system described by the homogenous second order equation y(n)-3y(n-1)-4y(n-2)=0 if the initial conditions are y(-1)=5 and y(-2)=0?

23. Due to non-uniform resolution, the corresponding error in a floating point representation is proportional to the number being quantized.

24. What is the expression for system function in z-domain?

25. What is the Fourier transform of the signal x(n) which is defined as shown in the graph below?

26. Type-2 chebyshev filters consists of ______________

27. If H(z) is the z-transform of the impulse response of an FIR filter, then which of the following relation is true?

28. If x(n) produces y(m), then x(n-n₀) does imply y(n-n₀) for any value of n₀.

29. In the frequency sampling method for FIR filter design, we specify the desired frequency response Hd(ω) at a set of equally spaced frequencies.

30. What is the real part of the N point DFT XR(k) of a complex valued sequence x(n)?

31. What is the z-transform of the signal x(n)=aⁿ(sinω₀n)u(n)?

32. What is the quantity ax(n-1) is called?

33. In Parks-McClellan program, an array of maximum size 10 that specifies the weight function in each band is denoted by?

34. Which of the following filter we use in least square design methods?

35. Every fourfold increase in the size N of the DFT requires an additional bit in computational precision to offset the additional quantization errors.

36. If H(s)=\(\frac{1}{s^2+s+1}\) represent the transfer function of a low pass filter (not Butterworth) with a pass band of 1 rad/sec, then what is the system function of a band pass filter with a pass band of 10 rad/sec and a center frequency of 100 rad/sec?

37. The equation x(t)=\(\sum_{k=-\infty}^{\infty}c_k e^{j2πkF_0 t}\) is known as analysis equation.

38. Which bit coder is required to code a signal with 16 levels?

39. An ideal filter should have zero gain in their stop band.

40. In Nth order differential equation, the characteristics of bilinear transformation, let z=re^jw,s=o+jΩ Then for s = \(\frac{2}{T}(\frac{1-z^{-1}}{1+z^{-1}})\), the values of Ω, ℴ are

41. If g(n) is a real valued sequence of 2N points and x₁(n)=g(2n) and x₂(n)=g(2n+1), then what is the value of G(k), k=0,1,2...N-1?

42. An analog high pass filter can be mapped to a digital high pass filter.

43. What is the equation for magnitude frequency response |H(jΩ)| of a low pass chebyshev-I filter?

44. What is the transform that is suitable for evaluating the z-transform of a set of data on a variety of contours in the z-plane?

45. The impulse invariance method and mapping of derivatives are inappropriate to use in the designing of high pass and band pass filters due to aliasing problem.

46. What is the stop band gain of a low pass filter with δ_S as the pass band attenuation?

47. What is the system function of all-zero filter or comb filter?

48. All energy signals will have an average power of ___________

49. The selection of the sampling rate F_s=1/T, where T is the sampling interval, not only determines the highest frequency (F_s/2) that is preserved in the analog signal but also serves as a scale factor that influences the design specifications for digital filters.

50. In the absence of an S/H, the input signal must change by more than one-half of the quantization step during the conversion, which may be an impractical constraint.