Physics Help Forum Quantifying electrical currents through inquiry

 Electricity and Magnetism Electricity and Magnetism Physics Help Forum

Apr 16th 2011, 07:10 PM   #1
Junior Member

Join Date: Apr 2011
Posts: 24
Quantifying electrical currents through inquiry

Hello again-

It's me Ray again with some more questions about electrical currents. I have attached two problems that I have answers for, but I am not sure if my answers and reasonings are correct.

for 5.3 i know that the total current = i and that

A = 3B

C = 2B

then if I say that B = i/6 this means that

B = i/6
A = 3i/6
C = 2i/6

and since i/6 + 3i/6 + 2i/6 = 6i/6 this must be correct

I am still working on 5.4
Attached Files
 Scan_Doc0034.pdf (246.4 KB, 3 views)

Apr 16th 2011, 07:27 PM   #2

Join Date: Apr 2008
Location: On the dance floor, baby!
Posts: 2,494
 Originally Posted by Ray3Ray3 for 5.3 i know that the total current = i and that A = 3B C = 2B then if I say that B = i/6 this means that B = i/6 A = 3i/6 C = 2i/6 and since i/6 + 3i/6 + 2i/6 = 6i/6 this must be correct
You are correct, but I think a better presentation would be to say that
i = A + B + C = 3B + B + 2B = 6B

Thus B = i/6, etc.

-Dan
__________________
Do not meddle in the affairs of dragons for you are crunchy and taste good with ketchup.

See the forum rules here.

 Apr 16th 2011, 07:34 PM #3 Junior Member   Join Date: Apr 2011 Posts: 24 Thanks Dan- That does make more sense to present it that way. Is 5.4 really simple and I am making it too hard? Here is what I thought when I first looked: Since A and C are in series they are both getting .4A through them. So this means that B must have .8A running through it, then the .4A and .8A join up as 1.2A to go through D and back to the battery.
Apr 17th 2011, 08:56 AM   #4

Join Date: Apr 2008
Location: On the dance floor, baby!
Posts: 2,494
 Originally Posted by Ray3Ray3 Thanks Dan- That does make more sense to present it that way. Is 5.4 really simple and I am making it too hard? Here is what I thought when I first looked: Since A and C are in series they are both getting .4A through them. So this means that B must have .8A running through it, then the .4A and .8A join up as 1.2A to go through D and back to the battery.
Your analysis looks good to me.

-Dan
__________________
Do not meddle in the affairs of dragons for you are crunchy and taste good with ketchup.

See the forum rules here.

 Tags currents, electrical, inquiry, quantifying

 Thread Tools Display Modes Linear Mode

 Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post Strontium90 Electricity and Magnetism 6 Jan 14th 2013 09:36 PM Ray3Ray3 Electricity and Magnetism 5 Apr 26th 2011 11:50 AM Ray3Ray3 Electricity and Magnetism 2 Apr 25th 2011 08:37 PM missyc8 Electricity and Magnetism 1 Aug 20th 2010 01:39 PM jhbguy Electricity and Magnetism 8 Aug 3rd 2009 10:39 AM