Question

A carrier wave $V_c\left(t\right)=160\sin (2\pi \times {10}^{6}t)\text{V}$ is made to vary between $V_{max}=200\text{V}$ and $V_{min}=120\text{V}$ by a message signal $V_m\left(t\right)=A_m\sin (2\pi \times {10}^{3}t)\text{V}$. The peak voltage $A_m$ of the modulating signal is _______$\text{V}$.

• A. 40
• B. 40.0
• C. 40.00

Answer 1

Answer: (A), (B), (C)

Maximum amplitude,

$A_{max}=A_m+A_c$

$\Rightarrow V_{max}=V_m+V_c$

$\Rightarrow 200=V_m+160$

$\Rightarrow V_m=40\text{V}$

$\therefore$ Peak voltage of modulating signal is, $A_m=40\text{V}$