Given, the amplitude of the carrier wave, Ac = 250 V The amplitude of the message wave, Am = 150 V We know that, The maximum amplitude, Amax = Ac+Am Substituting the values in the above equation, we get Amax = 250 + 150 = 400 V We know that, The minimum amplitude, Amin=Ac−Am Substituting the values in the above equation, we get Amin = 250 - 150 = 100 V Thus, the ratio of the minimum amplitude to the maximumamplitude of the modulated wave is