Official PYQ · 1999Set 1 · Q1.21Continuous-time SignalsMCQ1 mark

GATE EC 1999 Set 1 Q1.21 — Continuous-time Signals

A modulated signal is given by

$s(t)=e^{-a t} \cos \left[\left(\omega_{c}+\Delta \omega\right) t\right] u(t),$

where $a, \omega_{c}$ and $\Delta \omega$ are positive constants, and $\omega_{c} \gg \Delta \omega$ .

The complex envelope of $s(t)$ is given by

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Published 10 Oct 2026

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