Question:
The modulation frequency of an AM radio station is 250 $\mathrm{kHz}$, which is $10 \%$ of the carrier wave. If another AM station approaches you for license what broadcast frequency will you allot?
Correct Option: , 4
Solution:
(4) According to question, modulation frequency, $250 \mathrm{~Hz}$ is $10 \%$ of carrier wave
$\mathrm{f}_{\text {carricr }}=\frac{250}{0.1}=2500 \mathrm{KHZ}$
$\therefore$ Range of signal $2500 \pm 250 \mathrm{KHz}=2250 \mathrm{~Hz}$ to $2750 \mathrm{~Hz}$ For $2000 \mathrm{KHZ}$
$\mathrm{f}_{\text {mod }}=200 \mathrm{~Hz}$
$\therefore$ Range $=1800 \mathrm{KHZ}$ to $2200 \mathrm{KHZ}$