Question

An oscillator is producing $FM$ waves of frequency $2kHz$ with a variation of $10kHz$. What is the modulating index?

• A. $0.20$
• B. $5.0$
• C. $0.67$
• D. $1.5$

Answer 1

Answer: (B)

The formula for modulating index is given by
$m_f=\frac{\delta }{v_m}=\frac{\text{ Frequency variation }}{\text{ Modulating frequency }}$
$=\frac{10\times 10^3}{2\times 10^3}=5$