Question

If $E_{c}$ and $E_{m}$ are peak values of carrier and modulating signals, respectively then for $100 \%$ modulation,

• A. $E_{c}=\frac{E_{m}}{2}$
• B. $\frac{E_{c}^{2}}{2}=E_{m}^{2}$
• C. $E_{c}=E_{m}$
• D. $E_{c}=2 E_{m}$

Answer 1

Answer: (C)

Modulation index of a modulated signal is
$\mu=\frac{E_{m}}{E_{c}}$
Where, $E_{m}$ and $E_{c}$ are peak values of modulating signal and carrier signal.
For $100 \%$ modulation, modulation index should be unity.
Hence, $ \mu=1=\frac{E_{m}}{E_{c}}$
$\Rightarrow \,E_{m}=E_{c}$