TS EAMCET 11-Sep-2020 Shift 1 Solved Paper

Modulating signal is given as
where, ‌‌ω1>ω2 and ω3>ω1
Standard equation of modulating signal is given as
cos(ωc+ωm)‌t ...(ii)
Clearly, ωc>ωc−ωm and ωc+ωm>ωc
Eq. (i) can also be written as,
Comparing Eq. (ii) and Eq. (iii), we get
A1=Ac
ωc=ω1
ωc−ωm=ω2...(iv)
and ‌‌ωc+ωm=ω3....(v)
Also, ‌‌‌

µAc

2

=A2⇒µ=‌

2A2

A1

...(vi)
Substracting Eq. (iv) from Eq. (v), we have
ω3−ω2=(ωc+ωm)−(ωc−ωm)
⇒‌‌2ωm=ω3−ω2
⇒‌‌ωm=‌

ω3−ω2

2

...(vii)
From Eq. (vi) and (vii), option (d) is correct.