amplitude modulation

Question

In AM, carrier amplitude varies proportional to:

RankGuru · Accepted Answer

In Amplitude Modulation (AM), the instantaneous amplitude of the carrier wave is varied in accordance with the instantaneous amplitude of the modulating (message) signal. 
If the carrier is $C(t) = A_c \sin(\omega_c t)$ and message is $m(t)$, the AM wave is:
$x_{AM}(t) = [A_c + m(t)] \sin(\omega_c t)$.
The 'envelope' of the resulting wave follows the shape of the modulating signal.

Rank Guru

amplitude modulation

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