Question

What is the virtual value or effective value of a.c. ?

Answer 1

Alternating current:

1. Root Mean Square (R.M.S.) or A.C. Virtual Value or A.C. Effective Value is the fact that alternating current produces the same amount of heat as steady current when passed through resistance for the same amount of time.
2. Most AC voltmeters will display the effective or RMS value when used.
3. The effective value is less than the maximum value, being equal to $0.707$ times the maximum value.
4. $R.M.Svoltage{V_{rms}}^2=\frac{1}{T}{\int }_0^T{v}^2.dt$, where $v$ is the instantaneous voltage and $T$ is the time period.