An amplitude modulated wave is modulated to 50%. What is the saving in power if carrier as well as one of the side bands are suppressed
Answer & explanation
Correct answer: option 3
$P_{sb}=P_c(\frac{m_a}{2})^2=P_c\frac{(0.5)^2}{4}=0.0625P_c$
Also $P=P_c(1+\frac{m_a^2}{2})=P_c(1+\frac{(0.5)^2}{2})=1.125P_c$
∴ % saving = $\frac{1.125P_c-0.0625P_c}{1.125P_c}×100=94.4\%$