# Find the potential Difference

1. May 9, 2008

### looi76

1. The problem statement, all variables and given/known data
http://img241.imageshack.us/img241/1087/09052008hf9.png [Broken]
What is the potential difference across (i) AB (ii) BC.
2. Relevant equations
??
3. The attempt at a solution
(i) $$\frac{200}{400} \times 6 = 3V$$

Is this right?

Last edited by a moderator: May 3, 2017
2. May 9, 2008

### BishopUser

I think the easiest way to do this would be to use equivalent resistances to find the current. After that it is very easy

3. May 9, 2008

### looi76

I didn't understand...

4. May 10, 2008

### alphysicist

Hi looi76,

We know the total resistance between A and B is 200 ohms. What is the total resistance between B and C?

5. May 10, 2008

### looi76

The total resistance between B and C is 100 because they are connected in parallel. So, $$\frac{200}{(100 + 200)} \times 3 = 2V$$

Is this correct?

6. May 10, 2008

### Defennder

No, that is not the total resistance between B and C. They are both in parallel. What is the formula for resistance connected in parallel?