Solution:
Under Modulation:
According to the Modulation Index which is:
µ = Am/Ac or µ = (Amax – Amin)/(Amax + Amin)
If ‘µ’ is < 1, for example, the modulation index is 0.5 then modulated output would look similar to the following figure. It is named Under Modulation and such type of wave is called Under Modulated Wave.
Explanation:
In the shown figure the value of µ<1, so it means there are even some points where our modulated wave or signal (or we also named as Amplitude Modulated Signal) is not correct (as the point is Vmin).
Therefore due to this our message signal or wave is not accurately retrieved which we named Demodulated Signal.
Over Modulation:
If the value of Modulation index µ>1 for example, it’s 1.5 so that the wave or signal will be Over Modulated Wave which is displayed in the following figure:
Explanation:
As we notice in the figure above; increasing or we can say µ>1 then the unknown wave created in modulated signal (which is not essential of modulated signal/wave) and because of this over demodulated signal/wave also generates.
Total Modulation:
If the µ=1 then we named it as Total Modulation. Total Modulation is 100% perfect modulation for Amplitude Modulation and we can even name a Perfect Modulation.
Explanation:
The total modulation displayed in the above figure is perfect modulation for Amplitude Modulated Wave or Signal and due to this, we can efficiently retrieve over message signal/wave again.
