Question

In amplitude modulation, sinusoidal carrier frequency used is denoted by ${\omega }_c$ and the signal frequency is denoted by ${\omega }_m$. The bandwidth $(\Delta {\omega }_m)$of the signal is such that $\Delta {\omega }_m<<{\omega }_c$. Which of the following frequencies is not contained in the modulated wave ?

• A. ${\omega }_m$
• B. ${\omega }_c$
• C. ${\omega }_m+{\omega }_c$
• D. ${\omega }_c-{\omega }_m$

Answer 1

Answer: (A)

Modulated wave has frequency range
${\omega }_c\pm {\omega }_m$
$\therefore$ Since ${\omega }_c>>{\omega }_m$
$\therefore {\omega }_m$ is excluded.