Question

A $500Hz$ modulating voltage fed into an $FM$ generator produces a frequency deviation of $2.25kHz$. If amplitude of the voltage is kept constant but frequency is raised to $6kHz$ then the new deviation will be

• A. $4.5kHz$
• B. $54kHz$
• C. $27kHz$
• D. $15kHz$

Answer 1

The correct option is B $54kHz$

$$\begin{array}{c}Accordingtoquestion..............\\ mf=\frac{\delta }{f_m}=\frac{2250}{500}=4.5\\ Newdeviation=2\left(m_f{f}_m\right)\\ =2\times 4.5\times 6\\ =54k{H}_Z\\ sothatthecorrectoptionisB.\end{array}$$