Question

A signal of $5kHz$ frequency is amplitude modulated on a carrier wave of frequency $2MHz$. Frequencies of the resultant signal is/are

• A. $2MHz$ only
• B. $2005kHz$ and $1995kHz$
• C. $2005kHz$, $2000kHz$ and $1995kHz$
• D. $2000kHz$ and $1995kHz$

Answer 1

The correct option is C $2005kHz$, $2000kHz$ and $1995kHz$

$f_c=2MHz=2000KHz$
$f_m=5KHz$
The resultant frequencies are: $f_c-f_m$, $f_c$, $f_c+f_m$
Thus, the frequencies are $1995$, $2000$ and $2005KHz$.