Hazim Hassan

This set of Digital Signal Processing Multiple Choice Questions & Answers (MCQs) focuses on “Sampling Rate Conversion”.

1. The N^th root of unity W_N is given as _____________
a) e^j2πN
b) e^-j2πN
c) e^-j2π/N
d) e^j2π/N

2. Which of the following is true?
a) W∗N=1NWN−1
b) WN−1=1NWN∗
c) WN−1=WN∗
d) None of the mentioned

3. What is the DFT of the four point sequence x(n)={0,1,2,3}?
a) {6,-2+2j-2,-2-2j}
b) {6,-2-2j,2,-2+2j}
c) {6,-2-2j,-2,-2+2j}
d) {6,-2+2j,-2,-2-2j}

4. If X(k) is the N point DFT of a sequence whose Fourier series coefficients is given by c_k, then which of the following is true?
a) X(k)=Nc_k
b) X(k)=c_k/N
c) X(k)=N/c_k
d) None of the mentioned

5. Which of the following is true regarding the number of computations requires to compute an N-point DFT?
a) N² complex multiplications and N(N-1) complex additions
b) N² complex additions and N(N-1) complex multiplications
c) N² complex multiplications and N(N+1) complex additions
d) N² complex additions and N(N+1) complex multiplications

6. If W₄¹⁰⁰=W_x²⁰⁰, then what is the value of x?
a) 2
b) 4
c) 8
d) 16

7. Which of the following operation is performed by the blocks given the figure below?

a) Sampling rate conversion by a factor I
b) Sampling rate conversion by a factor D
c) Sampling rate conversion by a factor D/I
d) Sampling rate conversion by a factor I/D

8. Sampling rate conversion by the rational factor I/D is accomplished by what connection of interpolator and decimator?
a) Parallel
b) Cascade
c) Convolution
d) None of the mentioned

9. What is the DFT of the four point sequence x(n)={0,1,2,3}?
a) {6,-2+2j-2,-2-2j}
b) {6,-2-2j,2,-2+2j}
c) {6,-2+2j,-2,-2-2j}
d) {6,-2-2j,-2,-2+2j}

10. Which of the following has to be performed in sampling rate conversion by rational factor?
a) Interpolation
b) Decimation
c) Either interpolation or decimation
d) None of the mentioned