# Electronics Engineering Objective Questions { Discrete Time Signals and Systems }

1. The conclusion regarding the time invariance of the system is

2. Consider the following statements (A) If S1 and S2 are linear, then S is linear (B) If S1 and S2 are nonlinear, then S is nonlinear (C) If S1 and S2 are causal, then S is causal (D) If S1 and S2 are time invariant, then S is time invariant True statements are :

3.  Consider the following statements (A) If S and S2 are linear and time invariant, then interchanging their order does not change the system. (B) If S1 and S2 are linear and time varying, then interchanging their order does not change the system. True statements are :

4. The invertible system is

5. The transform of I'M) = e-4 u(t) is

6. f(t) is a pulse defined as f(t) = I for 0 < I = 0 otherwise. The even part of f(t) is
B. 1 for - 1
C. -2 for -1
D. 1 for - -2
7. A real signal x[nl with Fourier transform X(e) has following property I. xinl = 0 for n > 0 2. x101 > 0 3. Im {X(ein) = sin 0 - sin 20) 4. -1 7 ix(ei)12 di/ = 3 2_ The signal x(n) is

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