Question:
An amplitude modulated wave is represented by the expression $v_{m}=5(1+0.6 \cos 6280 t) \sin \left(211 \times 10^{4} t\right)$ volts The minimum and maximum amplitudes of the amplitude modulated wave are, respectively :
Correct Option: , 2
Solution:
(2) From the given expression, $V_{m}=5(1+0.6 \cos 6280 t) \sin \left(211 \times 10^{4} t\right)$
Modulation index, $\mu=0.6$
$\because A_{m}=\mu A_{c}$
$\frac{A_{\max }+A_{\min }}{2}=A_{c}=5$ ...(1)
$\frac{A_{\max }-A_{\min }}{2}=A_{m}=3$ ...(2)
From equation (i) $+$ (ii),
Maximum amplitude, $A_{\max }=8$.
From equation (i) - (ii),
Minimum amplitude $A_{\min }=2$.