Question

An amplitude modulated wave is as shown in figure. Calculate (i) the percentage modulation, (ii) peak carrier voltage and , (iii) peak value of information voltage.

A. 30V,20V
B. 10V,15V
C. 15V,30V
D. 20V,35V

Answer 1

Correct Answer - A

From figure.
`V_("max")=(100)/(2)=50VrArrV_("min")=(20)/(2)=10V`
Peak carrier voltage,
`V _(c)=(V_(max")+V_("min"))/(2)=(50+10)/(2)=30V`
Modulation index,
`mu=(V_("max"))/(V_("min"))(-V_("min"))/(+V_("min"))=(50-10)/( 50+10)=(40)/(60)=(2)/(3)`
Peak information voltage, `v_(m)=muV_(c)=(2)/(3)xx30=20V `