In an amplitude modulator circuit, the carrier wave is given by, C(t) = 4 sin (20000 π t) while modulating signal is given by, m(t) = 2 sin (200 π t). The values of modulation index and lower side band frequency are :

Question

In an amplitude modulator circuit, the carrier wave is given by, C(t) = 4 sin (20000 π t) while modulating signal is given by, m(t) = 2 sin (200 π t). The values of modulation index and lower side band frequency are : (A) 0.5 and 9 kHz (B) 0.5 and 10 kHz (C) 0.3 and 9 kHz (D) 0.4 and 10 kHz

Tardigrade Admin · Accepted Answer

Modulation index is given by m = (Am/Ac) = (2/4) = 0.5 (a) carrier wave frequency is given by = 2 π fc = 2 × 104 π (b) modulating wave frequency (fm) 2 π fm = 2000 π ⇒ fm = 1 kHz lower side band frequency ⇒ fc - fm ⇒ 10 kHz - 1 kHz = 9 kHz

Q. In an amplitude modulator circuit, the carrier wave is given by, C(t)=4 sin (20000πt) while modulating signal is given by, m(t)=2 sin (200πt). The values of modulation index and lower side band frequency are :

0.5 and 9 kHz

0.5 and 10 kHz

0.3 and 9 kHz

0.4 and 10 kHz

Modulation index is given by m=Ac​Am​​=42​=0.5 & (a) carrier wave frequency is given by =2πfc​=2×104π (b) modulating wave frequency (fm​) 2πfm​=2000π ⇒fm​=1kHz lower side band frequency ⇒fc​−fm​ ⇒10kHz−1kHz=9kHz

Q. In an amplitude modulator circuit, the carrier wave is given by, $C (t) = 4$ sin ( $20000 π t$ ) while modulating signal is given by, $m (t) = 2$ sin $(200 π t$ ). The values of modulation index and lower side band frequency are :