Correct Answer - Option 3 : Increased by 50 percent.
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
Analysis:
When μ = 0, the transmitted power will be:
\({P_t} = {P_c}\left( {1 + \frac{{{0^2}}}{2}} \right)=P_c\)
When μ = 1, the transmitted power will be:
\({P_t} = {P_c}\left( {1 + \frac{{{1^2}}}{2}} \right)=\frac{3}{2}P_c\)
The % increase in the modulated signal power is given by:
\(=\rm \frac{{\frac{3}{2}{P_C} - {P_C}}}{{{P_C}}} \times 100\%\)
\(\rm = \frac{{\frac{1}{2}{P_C}}}{{{P_C}}} \times 100 = 50\%\)
