CI 2-22. (Older Version)

[iahim]

The problem asks for the average value of the following waveform:

From 0 to1/180 ... 75V

From 1/180 to 1/120 ...120V

From 1/120 to 1/60 ... 95V

The CI solution states the durations are the same, so they divide the sum of the 3 voltages by 3 and get the result 97V.

I think the first interval is 1/3, the second 1/6 and the last interval 1/2. So the correct solution should be:

75/3 + 120/6 + 95/2 = 92.5V

If the middle interval would have been 1/90 (in lieu of 1/120), their solution would be right.

Am I wrong?

 

[EEpowerOK]

If it is the problem I remember, the center is not the center of the readings, look at the Y axis above and below the center. I viewed them as 1/3 each. Just a straight average.

 

[iahim]

EEpowerOK,

The intervals are drawn equal in the graph, but the values on the time axis are not. If you don't mind check your copy of the CI exam to see if the values are the same. Like I said, my version is not the latest.

 

[EEpowerOK]

I have the exact problem in CI 2-7, answer is 97, their all based on 60 hz intervals multiples, so 1/90 is not correct.