Please differentiate between v(rms) and V(avg/dc) of an Ac signal . Why do we use rms and why is vrms called effective value; why is vp not so called or (v(avg))? And why we use v rms to calculate power (avg)?
The average voltage of a pure AC signal is 0V. That's not a lot of use.
Vrms is widely used because it ensures that an AC voltage produces the same heating effect in a resistor as the equivalent DC voltage. This also means it will produce the same light from an incandescent lamp.