Q119 / 120 · VITEEE 2010 · Physics
An AM wave has $1800 \mathrm{~W}$ of total power content. For $100 \%$ modulation the carrier should have power content equal to
- A$1000 \mathrm{~W}$
- Correct answerB$1200 \mathrm{~W}$
- C$1500 \mathrm{~W}$
- D$1600 \mathrm{~W}$
Solution
Total power $P_{t}=P_{c}\left[1+\frac{m a^{2}}{2}\right] \because m a^{2}=1$
$$
\therefore 1800=P_{c}\left[1+\frac{1}{2}\right] \Rightarrow P_{c}=1200 \mathrm{~W}
$$
Hence, the correct answer is option: 'B'.