• Support PF! Buy your school textbooks, materials and every day products Here!

Finding the Potential at a specific point in this Circuit

  • Thread starter tmint
  • Start date
  • #1
6
0

Homework Statement


Here is the circuit: http://gyazo.com/1e11d9208da0aa29d10b72128844ad40
What is the Electric Potential at Point A?
Battery 1: 6.76 V
Battery 2: 11.8 V
Resistance 1: 100Ω
Resistance 2: 217Ω
Resistance 3: 312Ω



Homework Equations


Kirchhoff's Rules
V=IR


The Attempt at a Solution



I first set up my Currents so that Current 1(left)+ Current 2(down middle)= Current 3(right)

Let c be left of point a, b the point bottom of point a, d left of b, e right of point a and f right of b.


cabdc: -217(Current 1)+100(Current 2)=-6.76
=-217(Current 1)+100(Current 2)

aefba: -312(Current 3)-11.8-100(Current 2)=0
=-312(Current 3)-100(Current 2)=11.8

Let Current 2= Current 3-1

So..

-217(Current 1)+100(Current 3-1)=-6.76

-312(Current 3)-100(Current 3-1)=11.8

And I get

312(Current 3)-217(Current 1)+200(Current 3-Current 1)=-18.56

I'm stuck at this step, could use some help.

Thanks.
 

Answers and Replies

  • #2
NascentOxygen
Staff Emeritus
Science Advisor
9,244
1,072
It is difficult to spot errors (and easy to make them) when working without a diagram. But the two statements below seem to lack compatibility. Check the signs/directions you are using.

cabdc: -217(Current 1)+100(Current 2)=-6.76
Current 2= Current 3-1
 
Last edited:

Related Threads on Finding the Potential at a specific point in this Circuit

Replies
3
Views
8K
Replies
9
Views
687
Replies
1
Views
4K
Replies
10
Views
726
  • Last Post
Replies
12
Views
916
  • Last Post
Replies
6
Views
3K
Replies
10
Views
8K
Replies
1
Views
1K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
1
Views
2K
Top