Question

The transmission efficiency of an ordinary AM signal with a modulation percentage of 80% is:

• A. 24.24%
• B. 48.49%
• C. 20.22%
• D. 33.33%

Hint:

In AM efficiency calculations, always use $\dfrac{\mu^2}{\mu^2 + 2}$ where $\mu$ is the modulation index.

Answer 1

The Correct Option is A

Step 1: Formula.
Efficiency $\eta = \dfrac{\mu^2}{\mu^2 + 2} \times 100%$.

Step 2: Substitute $\mu = 0.8$. \[ \eta = \dfrac{0.64}{0.64 + 2} \times 100 = \dfrac{0.64}{2.64}\times 100 \approx 24.24%. \]
Final Answer: \[ \boxed{24.24%} \]