Question

If minimum voltage in an AM wave was found to be $2V$ and maximum voltage $10V$. The $\%$ of modulation index is :

• A. $80\%$
• B. $66.67\%$
• C. $64.25\%$
• D. $76.25\%$

Answer 1

The correct option is B $66.67\%$

$m_a=\frac{E_{max}-E_{max}}{E_{max}+E_{max}}=\frac{10-2}{10+2}=\frac{8}{12}=0.66667$

$m_a=66.67\%$