JEE PYQ: Communication System Question 26
Question 26 - 2019 (12 Apr 2019 Shift 2)
In an amplitude modulator circuit, the carrier wave is given by $C(t) = 4 \sin(20000\pi t)$ while modulating signal is given by $m(t) = 2 \sin(2000\pi t)$. The values of modulation index and lower side band frequency are:
(1) 0.5 and 10 kHz
(2) 0.4 and 10 kHz
(3) 0.3 and 9 kHz
(4) 0.5 and 9 kHz
Show Answer
Answer: (4)
Solution
$\mu = \frac{2}{4} = 0.5$. $f_c = 10000$ Hz, $f_m = 1000$ Hz. LSB $= f_c - f_m = 9000$ Hz $= 9$ kHz.
BETA
