Question

Sinusoidal carrier voltage of frequency $1.5\, MHz$ and amplitude $50\, V$ is amplitude modulated by sinusoidal voltage of frequency $10\, kHz$ producing $50 \%$ modulation. The lower and upper side-band frequencies in $kHz$ are

• A. 1490, 1510
• B. 15101490
• C. $\frac{1}{1490}, \frac{1}{1510}$
• D. $\frac{1}{1510}, \frac{1}{1490}$

Answer 1

Answer: (A)

1490, 1510

Answer 2

Here $f_{c}=1.5\, MHz =1500\, kHz ,\, f_{m}=10\, kHz$
$\therefore$ Low side-hand frequency
$=f_{c}-f_{m} =1500\, kHz -10\, kHz$
$=1490\, kHz$
Upper side-band frequency
$=f_{c}+f_{m} =1500\, kHz +10\, kHz$
$=1510\, kHz$