Can someone solve and explain the solutions to problems 8 and 9 on the following page: http://www.facstaff.bucknell.edu/mastascu/eLessonsHTML/Basic/Basic2i.html

Thanks in advance!

 

Q.8

300 hours.

The 1A current is drawn for ten minutes every hour. The AH drawn per hour is therefore (10/60)x1 or 1/6 AH per hour. the 50AH battery will last for

50/(1/6) = 300 hours

Q.9

50 hours.

On average the current is 1A - 50% time it is on at 2A % & 50% off.

So 1AH is consumed each hour. The 50AH battery will last for 50 hours.

 

I still don't get it. Can you explain the second one without using duty cycles? thanks

 

Do you need help understanding duty cycles? Or the formula to calculate AH?

On a test or real life, the numbers are different. In your case, understanding how the answer was attained is much more important than the actual answer.

 

I still don't get it. Can you explain the second one without using duty cycles? thanks

Half the time the battery supplies no current. The other half of the time, the battery supplies two amp. 50 AH / 2 A = 25 Hours. 25 hours is half of 50 hours. So the battery will last 50 hours.

 

I read up on duty cycles and now understand how the answer is attained. Thanks!