The modulation index is:
A) top envelope divided by center frequency
B) VCO voltage divided by center frequency
C) deviation divided by intelligence frequency
D) all of the above

Question

Quizplus · Accepted Answer

The modulation index, especially in frequency modulation (FM) and phase modulation (PM), is defined as the ratio of the frequency deviation (how much the carrier frequency varies) to the modulating signal frequency (intelligence frequency). This is why option C is correct.

The Modulation Index Is