DEFINITIONS

Voltage
	time

The properties of a sinusoidally varying current have the same names as those for other waves.

• The peak value is the maximum voltage in the cycle.
• The root mean squared (R.M.S) value is the square root of the average squared voltage, for a sinusoidally varing quantity this is equal to the maximum volatge V₀ over root 2. V_rms = ^V0 / _{SQR( 2 )}

WHY R.M.S
The power dissipated in a electric circuit is given by ¹/₂ I² R or putting V = I R in P = ¹/₂ V²/ _R, hence the R.M.S value of a AC circuit gives a value for the DC circuit voltage that would be needed to deliver the same power.