22. The auto eorelation function of white noise is
23. The spectral density of white noise is
24. The probability density function of the envelope of narrow band noise is
25. The Fourier transform of a Gaussian time pulse is 1 z2 ? z
26. The z-transform of a system is H(z)= z- 0.2 If the ROC is VI < 0.2, then impulse response of the system is
27. A causal LTI system is described by the difference equation 2yin] = ay[n -21- 2x[nl + 13x In -II The system is stable only if
28. The region of convergence of the z-transform of a unit step function is
