Signal Processing - Study Mode
[#151] A discrete LTI system is non-causal if its impulse response is
Correct Answer
(D) a n U(n + 2)
[#152] The linear constant coefficient difference equation $$yleft( n
ight) - frac{1}{2}yleft( {n - 1}
ight) = xleft( n
ight) + frac{1}{3}xleft( {n - 1}
ight)$$ xa0 xa0 xa0 xa0lead to
Correct Answer
(D) $$frac{{Yleft( Z
ight)}}{{Xleft( Z
ight)}} = frac{{1 + frac{1}{3}{Z^{ - 1}}}}{{1 - frac{1}{2}{Z^{ - 1}}}}$$
[#153] If the lower limit of Region of Convergence (ROC) is greater than the upper limit of ROC, the series $$Xleft( z
ight) = sum
olimits_{n = - infty }^infty {xleft( n
ight){z^{ - n}}} $$
Correct Answer
(C) Does not converge
[#154] A rectangular pulse train s(t) as shown in the figure is convolved with the signal cos 2 (4π × 10 3 t). The convolved signal will be a
Correct Answer
(A) DC
(E) DC
[#155] Two discrete time systems with impulse responses h 1 [n] = δ[n - 1] and h 2 [n] = δ[n - 2] are connected in cascade. The overall impulse response of the cascaded system is
Correct Answer
(C) δ[n - 3]