Google News
logo
Electronics and Communication Engineering (ECE) : Signals and Systems - Quiz(MCQ)
When is a complex exponential signal sinusoidal?
A)
σ =0 and Ω = 0
B)
σ = 0 and Ω ≠ 0
C)
σ < 0 and Ω = 0
D)
σ ≠ 0 and Ω ≠ 0

Correct Answer : Option (B) :   σ = 0 and Ω ≠ 0


Explanation : A signal is sinusoidal when σ = 0 and Ω ≠ 0
⇒ x(t) = est = e(σ+jΩ)t = eσt ejΩt = ejΩt = cosΩt + jsinΩt which is sinusoidal.

Advertisement