 # ECE Objective Questions { Discrete Time Signals and Systems }

8. The difference equation for this system relating any input x[n] and the corresponding output yin] is

9.  Which one of the following is the region of convergence (ROC) for the sequence In] = b" u(n) + b-n u(-n-1); Ibl < 1?

10. The system described by the difference equation y(n)-2y (n-1)+y(n-2)= x(n)-x(n-1) has y(n)= 0 and n<0. If x(n) = 8(n), then y(2) will be

11. Given that F(z) and G(z) are the one-sided Z transforms of discrete time functions f(nT) and g(nT), the Z transform of Ef(kT) g(nT - kT) is given by

12. Which one of the following represents the impulse response of a system defined by H(z) = z-1"?

13. If the function I-11(z) = (1 + 1.5 z-l-z-2) and H2(Z) = Z2 + 1.5 z-I, then

14. Consider the following statements regarding a linear discrete-time system Z2 +H(z) -(z + 0.5)(z - 0.5) 1. The system is stable. 2. The initial value h(0) of the impulse response is -4. 3. The steady-state output is zero for a sinusoidal discrete-time input of frequency equal to one-fourth the sampling frequency? Which of the statements are correct?

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