Necessary condition for sampling without distortion

Q2. The desired signal of maximum frequency w_m centered at frequency w=0 may be recovered if

Options:

a) The sampled signal is passed through low pass filter
b) Filter has the cut off frequency wm
c) Both a) and b)
d) None of the above

Correct Answer:

Explanation:

The original or desired signal may be recovered from the sampled signal by passing the signal through a low pass filter. The low pass filter should have the cut off frequency equal to w_m so that it allows only low frequencies up to the cut off frequency to pass through. The other higher frequencies in the sampled signal are rejected by the low pass filter.