Question

Draw a plot of the variation of amplitude versus ω for an amplitude modulated wave. Define modulation index. State its importance for effective amplitude modulation.

Answer 1

Plot of variation of amplitude versus ω  for amplitude modulated wave is shown in fig

Modulation Index: The ratio of amplitude of modulating signal to the amplitude of carrier wave is called modulation index i.e.,

m_a = E_m/E_c

For effective amplitude modulation the modulation index determines the distortions, so its value is kept ≤1 for avoiding distortions.