-
A DSB-SC wave is generated with fc = 1 MHz, V0 = a0Vi + a1Vi3
where, Vi = A′c cos (ω′ct) m(t) then f ′c′is—
-
- 1 MHz
- 0·33 MHz
- 0·5 MHz
- 3 MHz
- 1 MHz
Correct Option: C
Given that,
V0 = a0Vi/sub>+a1Vi3
= a0[A'ccosω'ct+m(t)]+a1[A'ccosω'ct+m(t)3]
= a0A'ccosω'ct+a0m(t)+a1[A'c3cos3ω'ct+m3(t)+3A'ccosω'ct m(t){A'ccosω'ct+m(t)}
Here we are interested in m(t) cos ω′c t component as it is DSB-SC wave.
V0 = 3(A'c)2a1cos2ω'ct m(t)
neglecting all the termsV0 = [1+cos'2ω'ct] 2
On comparing, we get
2ωc = ωc
or 2f';c = fc = 1
or f'c = = 0.5 MHz 2
Hence alternative (C) is the correct choice.
