An AM wave has \(1800 \mathrm{~W}\) of total power content for \(100 \%\) modulation the carrier should have…

An AM wave has \(1800 \mathrm{~W}\) of total power content for \(100 \%\) modulation the carrier should have power content equal to
  1. \(1000 \mathrm{~W}\)
  2. \(1200 \mathrm{~W}\)
  3. \(1500 \mathrm{~W}\)
  4. \(1600 \mathrm{~W}\)

Solution

Total power of AM wave, \(P_t=1800 \mathrm{~W}\) For \(100 \%\) modulation, depth of modulation, \(m=1\) If \(P_c\) be the carrier power, then we know that, \(\begin{aligned} & & P_t=P_c\left(1+\frac{m^2}{2}\right) \\ \Rightarrow & P_t & =P_c\left(1+\frac{1}{2}\right) \Rightarrow P_t=\frac{3}{2} P_c \\ \Rightarrow & P_c & =\frac{2}{3} P_t \quad=\frac{2}{3} \times 1800=1200 \mathrm{~W} \end{aligned}\)

Asked in: AP EAMCET 2020 (18 Sep Shift 1)

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