D E192029 Pages:3

b) The impulse response of a system is given by h[m] = 3”u[—n]. Find whether the (4)

system is causal, stable and dynamic

PART D
Answer any two full questions, each carries 10 marks.
15 a) Determine the causal signal x[n], if the Z-transform of the signal is given by (6)

1

X@) = Gna

b) ⋅ 11 ⋅ ⋅ (4)
An LTI system has the impulse response 112] = (3) u[n]. Determine the input

n −⋅∎∎⋅
∘∱⋔⊜⊰≻∣⊱↥⊜⋯⇂∎∱⋔∁∘∐↥⊑⋯⊔∎≊⊃↾∣∏⋮∣−− 68 u[n] + (=) u[n]

ല്‍ ஐ
16 9) Find the Z-transform and ROC of x[n] =n (=) u[n] * (೬) u[—n]. Symbol * (6)

4
represents convolution
b) If a discrete time periodic signal has periodicity N, write its Fourier series (4)
representation. Write down any three differences between continuous time and
discrete time Fourier series

17 The impulse response of a discrete time system is given by (10)

212] = [മ] + 6[n—-1] + न — 2]. Find the system frequency response

H(w) and plot the magnitude and frequency spectra

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