A. |a|r1<|z|<|a|r2
B. |a|r1>|z|>|a|r2
C. |a|r1<|z|>|a|r2
D. |a|r1>|z|<|a|r2
Answer: Option A
Explanation:
Given ROC of X(z) is r1<|z|
Question 3
If X(z) is the z-transform of the signal x(n) then what is the z-transform of anx(n)?
A. X(az)
B. X(az-1)
C. X(a-1z)
D. None of the mentioned
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Question 4
If X(z) is the z-transform of the signal x(n), then what is the z-transform of the signal x(-n)?
A. X(-z)
B. X(z-1)
C. X-1(z)
D. None of the mentioned
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Question 5
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
View Answer
Answer: Option B
Explanation:
A sampling rate conversion by the rational factor I/D is accomplished by cascading an interpolator with a decimator.
Question 6
The Nth root of unity WN is given as _____________
A. ej2πN
B. e-j2πN
C. e-j2π/N
D. ej2π/N
View Answer
Question 7
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}
View Answer
Question 8
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
View Answer
Answer: Option A
Explanation:
We emphasize that the importance of performing the interpolation first and decimation second, is to preserve the desired spectral characteristics of x(n).
Question 9
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
View Answer
Question 10
Which of the following justifies the linearity property of z-transform?[x(n)↔X(z)].
A. x(n)+y(n) ↔ X(z)Y(z)
B. x(n)+y(n) ↔ X(z)+Y(z)
C. x(n)y(n) ↔ X(z)+Y(z)
D. x(n)y(n) ↔ X(z)Y(z)
View Answer
Answer: Option B
Explanation:
According to the linearity property of z-transform, if X(z) and Y(z) are the z-transforms of x(n) and y(n) respectively then, the z-transform of x(n)+y(n) is X(z)+Y(z).