Final answer:
The average value of a full-cycle sinusoidal voltage signal with a peak value of 4 V is zero, but the average of the rectified signal's magnitude is about 1.27 V.
Step-by-step explanation:
To find the average value of a sinusoidal wave like a voltage signal Va, which has a maximum (peak) value of 4 V, we use the mathematical definition of the average value for one full cycle of a sine wave. The average value of a full-cycle sinusoidal signal is zero since the positive half-cycle cancels out the negative half-cycle. However, in practice, when the average value of the magnitude is needed (such as in rectified signals), the average of a sinusoidal wave's absolute value over a cycle is Vpeak / π, so for a 4 V peak, the average value would be 4 V / π ≈ 1.27 V.