Andhra University 2007 B.E fluid mechanics - Question Paper

. a. What is meant by signal? Contrast the differences ranging from

energy and power signal. 3

b) discuss operations on signals 3

c) How can we represent a signal by orthogonal set of functions

in time? 3

d) discuss various kinds of signals 3

e) How many various kinds of signal transformations are there

and discuss with example. 3

2. a) describe Z-transform and its properties. 8

b) obtain the Z-Transform of x(n)=-anu(-n-1). And provide

the region of convergence. 7

3. a) describe Fourier transform and its properties 10

b) obtain the Fourier tranform of x(n)=e-at cos (wt+F) . 5

4. a) State and Prove Sampling Theorem. 8

b) What is the effect of aliasing discuss with example. 7

5. a) How do you represent a discrete time signal as sum of infinite

impulses? 8

b) describe inverse Z-transform and methods of deducing it. 7

II Year B.E./B.Tech Degree exam

SIGNALS AND SYSTEMS

Electronics & Communication Engineering

Time : 3 hours Maximum : 75 Marks

ques. one is compulsory

ans any 4 from ques. two to 8

All ques. carry equal marks

21

6. a) discuss auto-correlation and cross-correlation of signals by

taking necessary examples 6

b) discuss Basic operation that can be performed on the signals

9

7. a) discuss discrete Time Decimation and Interpolation 5

b) describe trigonometric Fourier Series and provide the formulae

for the Fourier coefficients. 10

8. Write a note on 15

a) Causality

b) Stability

c) Linearity

Earning:   Approval pending.