It varies depending on how strong you want the signal to come through on the receiving end.
Modulation Index is the ratio of the maximum deviation frequency to the frequency of modulation. In other words it is the ratio of the spread in frequency spectrum to the frequency that was used to...
Themodulation index of a modulation scheme describes by how much the modulated variable of the carrier signal varies around its unmodulated level
ya, it can be negative because as m=Vm/Vc , the value of Vm if taken in negative then modulation index can be naegative
ζδΈη₯ι-look it up