Question

The peak value of a sine wave is equal to 240 vac. Whats the average value of the waveform?

A. 114.14V
B. 152.64V
C. 169.68V
D. 120.74V

Answer 1

B. 152.64

Step-by-step explanation:

The average value of a sinusoidal waveform taken over half cycle is given by

`V_(avg)=(2)/(\pi ) V_(peak)`

or simplifying it further results in;

`V_(avg)=0.637 V_(peak)`

We are given
`V_(peak)=240`

`V_(avg)=(2)/(\pi )(240)`

`V_(avg)=152.7V`

Hence option B is the right answer

Please note:

The average value of a pure sinusoidal wave over a full cycle (0 to 360°) is always zero since the positive and negative half cancel out each other due to being symmetric.

This is why we always take average over half cycle (0 to 180°).