Electronics and Communication Engineering - Signals and Systems - Discussion

Discussion Forum : Signals and Systems - Section 3 (Q.No. 2)
2.
which one is discrete time periodic signal?
sin 3pn
cos 2pn
sin 3pn
all
Answer: Option
Explanation:

In Discrete time signal irrational function cannot be periodic, frequency must be rational.

Hence only (c) is periodic.

sin 3pn = sin 3p(n + N) ⇒ for Periodic 3pN = 2Kp

.

Discussion:
3 comments Page 1 of 1.

Shurti said:   10 years ago
Option A and B are also rational.

Geethika said:   9 years ago
A and B are irrational.
(1)

RISHI NIGAM said:   3 years ago
C is right, because the time period has to be rational for periodictity but in B and C irrational terms will arise which will not make it rational.

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