Correct Answer - Option 4 : 660 W

__Concept__:

The total transmitted power for an AM system is given by:

\({P_t} = {P_c}\left( {1 + \frac{{{μ^2}}}{2}} \right)\)

Pc = Carrier Power

μ = Modulation Index

__Calculation__:

With PC = 500 W and μ = 0.80, the total power in the modulated wave will be:

\({P_t} = {500}\left( {1 + \frac{{{(0.8)^2}}}{2}} \right)\)

Pt = 660 W

__Note__: The transmitted power is independent of the modulation index in the case of FM and PM.