Question

A signal \(x(t)\) is given below : \[ x(t)=\left(\frac{3}{2}\right)\cos(190\times10^3\pi t)+5\cos(200\times10^3\pi t)+\left(\frac{1}{2}\right)\cos(210\times10^3\pi t) \] What is the power efficiency in the AM signal?

• A. \(25.4%\)
• B. \(15.3%\)
• C. \(18.0%\)
• D. \(11.1%\)

Hint:

For standard AM: \[ \eta=\frac{\mu^2/2}{1+\mu^2/2} \] Maximum AM efficiency occurs at: \[ \mu=1 \] giving: \[ \eta_{max}=33.3% \]

Answer 1

The Correct Option is C