Consider the amplitude modulated (AM) signal Ac cos ωct + 2 cos ωmt cos ωct For demodulating the signal using envelope detector, the minimum value of Ac should be-A-2B-1C-0.5D-0-A-2

A 2 AC cos ωct + 2 cos ωmt cos ωct AC cosωct for envelope detection μ < 1 ⇒ < 1 ⇒ Ac should be at least 2.