Page 280 - Basic Electrical Engineering

cycle. If we integrate the values for a complete cycle and take its average
over one cycle, the quantity becomes equal to zero. The average value if
calculated over a complete cycle would become zero.

or,

Average value of a sinewave or any other symmetrical wave over a complete

cycle is zero

For half-wave or full-wave rectified waves we need to calculate the average
value. When we intend to calculate the average value of such waves, we

calculate the average value for one-half cycle.
The average value is calculated as

or,

Effective or RMS value

The effective value or RMS value of an alternating quantity is determined by

considering equivalent heating effect.
The effective value of an alternating quantity (say current) is that the value

of dc current which when flowing through a given circuit element (say a
resistance element) for a given time will produce the same amount of heat as

produced by the alternating current when flowing through the same circuit
element for the same time.