B B4B0084

Total Pages: 2
Reg No.: Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FOURTH SEMESTER B.TECH DEGREE EXAMINATION, JULY 2017

Course Code: EC202
Course Name: SIGNALS & SYSTEMS

Max. Marks: 100 Duration: 3 Hours
PARTA
Question No. 3 is compulsory. Answer question 1 or 2
1 a) Distinguish between energy and power signals. Give anexample foreach category. (4)

0) A system has input - output relation given by [9] = 77.71]. Determine whetherthe (5)

system is memoryless, causal, linear, time invariant or stable.
1 12721 (6)
0 01107150
Sketch x(3t + 2),x(2(t-—2))and x(—2r-1).
OR
2 a) Derive the condition for stability of a discrete time LTI system in terms of its (4)
impulse response.
b) Given [11] 7111] and x,[n]={1,2}. Find convolution of the sequences (5)

A signal is given by x(t) =|

graphically.
9 ForanLTIsystem, unit impulse response is given by h(t)=e““u(t), ௪0. Obtain (6)
step response of the system.
3 ஐ Whatare the three differences between discrete time sinusoids and continuous time (4)
sinusoids? Find the fundamental period of जुआ] = cosIIn, if periodic.

b) (5)

An LTI system is described by y[n]— न y[n - 1] = x[n]. Assuming initial conditions

as zero, find its impulse response
1 | °

y[n]
೨) + ணை 13|| ടം

ದ್‌ | ष्ण ‏ہہ بإ‎

Given Al{n]=u[n], h2[n]=u[n+2]—u[n]and h3[n] = d[n - 2]. Find the overall
impulse response of the given system.
PART B
Question No. 6 is compulsory. Answer question 4 or 5

4 a) Explain Dirichlets conditions for the existence of Fourier Transform of 2 (4)

continuous time signal.
b) Determine the complex exponential Fourier Series representation of the signal, (5)

x(t) = cos4t + sin6t.

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