Browse Questions

# An audio signal given by $20\sin(2\pi \times 4000t)$ is used for modulating carrier wave given by $40\sin (2\pi\times 400000t)$.The frequency spectrum of modulated wave

$\begin{array}{1 1}(a)\;\text{430-460KHz}\\(b)\; \text{396-404KHz}\\(c)\;\text{400-404KHz}\\(d)\;\text{396-400KHz}\end{array}$

Can you answer this question?

Lower band is $400000-4000=396$KHz
Upper band is $400000+4000=404$KHz
Hence (b) is the correct answer.
answered Mar 17, 2014