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

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) 1510,1490 (C) (1/1490), (1/1510) (D) (1/1510), (1/1490)

Tardigrade Admin · Accepted Answer

Here, fc=1.5 MHz =1500 kHz , fm=10 kHz ∴ Low side band frequency =fc-fm=1500 kHz -10 kHz =1490 kHz Upper side band frequency =fc+fm=1500 kHz +10 kHz =1510 kHz

Q. Sinusoidal carrier voltage of frequency $1.5 M Hz$ and amplitude $50 V$ is amplitude modulated by sinusoidal voltage of frequency $10 k Hz$ producing $50%$ modulation. The lower and upper side-band frequencies in $k Hz$ are

1490,1510

1510,1490

$\frac{1}{1490}, \frac{1}{1510}$

$\frac{1}{1510}, \frac{1}{1490}$

Here, $f_{c} = 1.5 M Hz = 1500 k Hz, f_{m} = 10 k Hz$
$∴$ Low side band frequency
$= f_{c} - f_{m} = 1500 k Hz - 10 k Hz = 1490 k Hz$
Upper side band frequency
$= f_{c} + f_{m} = 1500 k Hz + 10 k Hz = 1510 k Hz$

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

1490,1510

1510,1490

14901​,15101​

15101​,14901​

Here, fc​=1.5MHz=1500kHz,fm​=10kHz ∴ Low side band frequency =fc​−fm​=1500kHz−10kHz=1490kHz Upper side band frequency =fc​+fm​=1500kHz+10kHz=1510kHz

Q. Sinusoidal carrier voltage of frequency $1.5 M Hz$ and amplitude $50 V$ is amplitude modulated by sinusoidal voltage of frequency $10 k Hz$ producing $50%$ modulation. The lower and upper side-band frequencies in $k Hz$ are

$\frac{1}{1490}, \frac{1}{1510}$

$\frac{1}{1510}, \frac{1}{1490}$

Here, $f_{c} = 1.5 M Hz = 1500 k Hz, f_{m} = 10 k Hz$
$∴$ Low side band frequency
$= f_{c} - f_{m} = 1500 k Hz - 10 k Hz = 1490 k Hz$
Upper side band frequency
$= f_{c} + f_{m} = 1500 k Hz + 10 k Hz = 1510 k Hz$