B B4B082 Pages: 4

Reg. No. Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FOURTH SEMESTER B.TECH DEGREE EXAMINATION, MAY 2017

Course Code: EC202
Course Name: SIGNALS & SYSTEMS

Max. Marks: 100 Duration: 3 Hours

PART A
Question No. 3 is compulsory.

1. a) Plot the signal x(t) = u(t + 1) + 2u(t) - u(t - 3) - 2u(t - 5) (4)

b) Check the periodicity of given signals. Find the fundamental period if periodic

i) x(t) =10sin 25 mt + cos 10 mt

00 717೬ ⋅ ⊺∏↧ 777೩ 7೯
ii)x(n)=cos —-—sin -- + 3 605 (= + 3 (4)
2 8 4 3
c) Determine whether the following system is time invarient, linear and causal.

1
x(n-1)

y(n) =x(n) + (5)

d) Evaluate the following integral ine cos (mt) 6(21- 10)dt (2)
OR

2. a) What is the output sequence of a LTI system with impulse response h(n)=[3 , 2] to the
input x(n)=[1, 2,3, 3]? (5)
b) Compute the auto correlation of the signal x(n) = a"u(n) for 0> 8 < 1 (6)
c) Check the causality and stability of the systems whose impulse responses are given
1) h(t) = e“u(t)ii) ട 2"u(—n) (4)
(a<0)
3. a) Find the output of an LTI system whose impulse response is h(t) to the input x(t).

A(t) = u(t) - u(t - 1)

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