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  1. A sinusoidal 10 cos ωct, ωc = 106 rad/sec is amplitude modulated using another sinusoidal Am cos ωmt, ωm = 103 with 100% modulation, then the expression for AM modulated wave is expressed as—
    1. 10 (1 + 0·1 cos 103t) cos 106t
    2. 1·(1 cos 103t) cos 106t
    3. 10(10 + 0·1 cos 103t) cos 106t
    4. 10(1 + 1·cos 103t) cos 106t
Correct Option: D

AM modulated wave is expressed as
δ(t) = Ac[1 + μ cos ωmt] cos ωct
given,
Ac = 10

μ =
Am
=
Am
= 1
Ac10

(∴ 100% modulation)
or
Am = 10
ωm = 103 rad/sec
ωc = 106 rad/sec
Hence, s(t) = 10[1 + 1.cos 103t] cos 106t



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