Q 12-08-227JEE MainJEE Main 2017 (8 Apr)Easy
A signal of frequency $20$ kHz and peak voltage of $5$ volt is used to modulate a carrier wave of frequency $1.2$ MHz and peak voltage $25$ volts. Choose the correct statement.
Answer: (C) Modulation index $= 0.2$, side frequency bands are at $1220$ kHz and $1180$ kHz.
$$\mu = \frac{A_m}{A_c} = \frac{5}{25} = 0.2$$
Side bands: $f_c\pm f_m = 1200\pm20$ kHz, i.e. $1220$ kHz and $1180$ kHz.
Solution by Sreeraj P, M.Sc Physics