EC2204 SIGNAL & SYSTEM IMPORTANT QUESTION FOR NOV/DEC 2013

**THIS QUESTIONS ARE IMPORTANT QUESTIONS ONLY THIS MAY OR MAY NOT COME FOR EXAMS . WHO NEED GOOD GRADE PLEASE HAVE A LOOK OF ALL QUESTIONS


Unit 1


1. (a) For the systems represented by the following functions. Determine whether
every system is (1) stable (2) Causal (3) linear (4) Shift invariant (4)
(i) T[x(n)]= ex(n)
(ii) T[x(n)]=ax(n)+6
2. Determine whether the following systems are static or Dynamic, Linear or Nonlinear,Shift variant or Invarient, Causal or Non-causal, Stable or unstable. (4)
(i) y(t) = x(t+10) + x2(t)
(ii) dy(t)/dt + 10 y(t) = x(t)
3. Explain about the properties of continuous time fourier series. (8)
4. Find the fourier coefficients of the given signal. (4)
x(t) = 1+ sin 2_ot + 2 cos 2_ot + cos (3_ot + _/3)
5. Determine the Fourier series coefficient of exponential representation of x(t)
x(t) = 1, ItI (8)
          0, T1< ItI < T/ 2 
6. Find the exponential series of the following signal. (8) 
7. Find which of the following signal are energy or power signals. (8)
                     a) x(t)=e-3t u(t) b) x(t) = ej(2t+_/4) c) x(n)= cos(_/4n) 
8. Explain the properties of Discrete time fourier serier (8) 
9. Find the cosine fourier series of an half wave rectified sine function. (8)
10. Explain the classification of signals with examples. (8)

Unit 2

    1.    State and prove properties of Fourier transform.                                                  (16)

 2.a. State the properties of Fourier Series.                                                               (8)
b. Use the Fourier series analysis equation to calculate the coefficients ak for the
continuous-time periodic signal                                                                     (8)
1.5,  0  t 1;<
x (t ) <
1.5, 1  t  2<
with fundamental frequency ω0= It.
  3.    a. State and prove Parseval’s power theorem and Rayleigh’s energy theorem.      (8)
b. Find the cosine Fourier series of an half wave rectified sine function.               (8)
  4.    A system is described by the differential equation,
d2y(t)/dt2+3dy(t)/dt+2y(t)= dx(t)/dt if y(0) =2;dy(0)/dt = 1 and x(t)=e-t u(t)
Determine the response of the system to a unit step input applied at t=0.           (16)

   5.    Find the Fourier transform of triangular pulse x (t) = _(t/m) ={1-2|t|/m |t|

0 otherwise                                                                                         (16)
            6.    Determine the Fourier series coefficient of exponential representation of x(t) x(t) = 1, ItI

                   0, T1< ItI < T/ 2                  (16)


                          UNIT III
 1.    a. Give the properties of convolution Integral                                                      (8)
b. Determine the state Equations and Matrix representation of systems              (8)
2.      a. Describe the properties of impulse response                                                    (8)
b. Determine y(t) by convolution integral if x(t)=e at u(t) and h(t)=u(t)             (8)
3.      a. Find whether the system is causal or not?
h(t)=e-2t u(t-1)                                                                                               (8)
b. Give the summary of elementary blocks used to represent continuous time
Systems                                                                                                                (8)
 4.    Find the natural and forced response of an LTI system given by                        (16)
10dy (t)/dt+2y(t)=x(t)


Univt 4
1.      State and prove properties of DTFT.                                                                               (16)
2.      a. Find the DTFT of x(n)={1,1,1,1,1,1,0,0}.                                                                   (8)
b. Find the convolution of x1(n)={1,2,0,1} , x2(n)={2,2,1,1}                                        (8)
3.      a. State and prove the sampling theorem.                                                                        (8)
b Derive the Lowpass sampling theorem.                                                                        (8)
4.      Find the z-transform of x(n)= an u(n) and for unit impulse signal                                  (16)
5.      a. Give the relationship between z-transform and Fourier transform.                             (8)
b. Determine the inverse z transform of the following function                                      (8)
x(z)=1/(1+z-1) (1-z-1 )2 ROC : |Z>1|


Unit 5

1.      a. State and prove the properties of convolution sum.                                                    (8)
b. Determine the convolution of x(n)={1,1,2} h(n)=u(n)-u(n-6) graphically                   (8)
2.      Determine the parallel form realization of the discrete time system
y(n) -1/4y(n-1) -1/8 y(n-2) = x(n) +3x(n-1)+2x(n-2)                                                  (16)
3.      a. Determine the transposed structure for the system given by difference equation
y(n)=(1/2)y(n-1)-(1/4)y(n-2)+x(n)+x(n-1)                                                                  (8)




b. Realize H(s)=s(s+2)/(s+1)(s+3)(s+4) in cascade form                                                  (8)
4. a. Determine the recursive and nonrecursive system                                                         (8)
b. Determine the parallel form realization of the discrete time system is
y (n) -1/4y(n-1) -1/8 y (n-2) = x(n) +3x(n-1)+2x(n-2)                                                     (8)


No comments:

Post a Comment