SRM University 2007 B.Tech Electronics and Communications Engineering BANK : Signals and Systems - Question Paper

S.R.M. Institute of Science & Technology
School of Electronics & Communication Engineering

ques. BANK
Sub. Code : EC209
Sub. Name : Signals and Systems
Year & Sem : II Year IIIrd Sem (ECE)

Unit- I

PART – A

1. Define a signal
2. Define deterministic and random signals
3. Define step
4. Define periodic and aperiodic signals
5. Define symmetric and antisymmetric signals
6. Define energy and power signals.
7. What is the period T of the signal x(t)= two Cos(t/4)
8. Define continuous-time, discrete-time and digital signals.
9. What is the value of the subsequent integral?
-? ?? x(t) ? (at-b) dt
10. What are the various kinds of representations of DT Signals?
11. Define a system
12. Define i) CT Signals ii) DT Signals
13. What are the classifications of systems?
14. Define Linear Time Invariant (LTI) System
15. Is the system
Y(t) = y (t-1) + 2ty(t-2) time-invariant?
16. Define static and dynamic system
17. Define a causal system.
18. What is a stable system?
19. List the basic operations on signals
20. What are the classifications of signals?
21. Define Even and Odd Signals.
22. Define CT and DT Signals.
23. Define causal and non-causal signals.
24. Define Lumped-parameters and distributed-parameter system.
25. Define causal and Non-Causal System
26. Define Linear and Non-Linear Systems.
27. Define Time-invariant and Time-variant system
28. Define stable and non-stable systems.
29. Define Invertible and non-Invertible system.
30. Define BIBO stable system.
31. List the transformations in independent variables of signals.
32. Find out the energy of the provided signal
X(t) = {2|t| (?=5 secs)}
= { 0, elsewhere}
33. Sketch the function x(t)= u(t)-2u(t-2) +3u(t-4) –u(t-5).
34. Find out the x(-2t-2). provided x(t)



35. Find out x(t)=2 Cos(10t+1) – Sin(4t-1) is periodic
36. Find out the energy of the provided signal x(t)m = {5. |t| < ? (?=2 secs)}
37. Sketch the function x(t) = r(-0.5t +2).
38. Find out x(-2t-2). provided x(t)




39. Find out x(t)=3 Cos(15t+1) – Sin(6t-1) is periodic.
40. Find out x(n)= three Cos [2n/3] is periodic
41. Define impulse function and state its properties.
42. Given y(t)= x(t-1) obtain out whether the system is causal.
43. Classify the subsequent signal as a) periodic or non periodic, energy or power signal
i. e?t , ? > 1
ii. e-j2?ft
44. Is a diode linear device? provide your cause.
45. A Signal x(t)= cos2?t is passed through a device whose input output is related by y(t)= x2(t), elaborate the frequency components in the output.
46. Draw the waveform x(-t) & x(2-t) of the signal
i. X(t)= { t 0 < = t <=3
1 t > 3
47. What is the total energy of DT signal x[n] which takes the values of unity at n=-1 , 0 & 1?

Earning:   Approval pending.