GO Electrical
0 votes

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 a cutoff at $25$ $Hz$. The filter output is seen to be a sinusoid of frequency $20$ $Hz$. This means that $x(t)$ has a frequency of

  1. $10$ $Hz$
  2. $60$ $Hz$
  3. $30$ $Hz$
  4. $90$ $Hz$
in Signals and Systems by (9.2k points)
recategorized by

Please log in or register to answer this question.

Welcome to GATE Overflow, Electrical, where you can ask questions and receive answers from other members of the community.

846 questions
36 answers
25,893 users