In an amplitude modulation, a modulating signal having amplitude of X V is superimposed with a carrier signal of amplitude Y V in first case. Then, in second case, the same modulating signal is superimposed with different carrier signal of amplitude 2Y V. The ratio of modulation index in the two case respectively will be:
(1) 1 : 2
(2) 1 : 1
(3) 2 : 1
(4) 4 : 1
