Noise constitutes a pure stochastic signal and is therefore "totally non-periodic"
(a) Examine the amplitude and phase spectra of noise. Is the spectrum continuous? Do amplitude and phase spectra display stochastic behaviour?
(b) Examine the amplitude and phase spectrum of lowpass filtered noise (e.g. cutoff frequency 50 Hz, BUTTERWORTH filter 6th order). Do both exhibit stochastic behaviour? Is the filtered noise also "completely non-periodic"?