# In amplitude modulation,the band width is

$\begin{array}{1 1}(a)\;\text{Equal to signal frequency}\\(b)\; \text{Twice the signal frequency}\\(c)\;\text{Three times the signal frequency}\\(d)\;\text{Four times the signal frequency}\end{array}$

Band width is equal to twice the frequency of modulating signal.
Hence (b) is the correct answer.