Q. A $500\ Hz$ modulating voltage fed into an FM generator produces a frequency deviation of $2.25\ kHz$. If amplitude of the voltage is kept constant but frequency is raised to $6\ kHz$ then the new deviation will be
A) $4.5\ kHz$
B) 54 $kHz$
C) 27 $kHz$
D) 15 $kHz$
Explanation
(b) $m_{f} = \frac{\delta}{f_{m}} = \frac{2250}{500} = 4.5$
$\therefore$ New deviation $= 2\left( m_{f}\ f_{m} \right) = 2 \times 4.5 \times 6 = 54\ kHz$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.