Q. 44 A sinusoid x(t ) of unknown frequency is sampled by an impulse train of period
20 ms. The resulting sample train is next applied to an ideal lowpass filter with
cutoff at 25 Hz. The filter output is seen to be a sinusoid of frequency 20 Hz. This
means that x(t )
(A) 10 Hz
(B) 60 Hz
(C) 30 Hz
(D) 90 Hz
Answer:(C)
Explanation:
Excellent