# Electric Field and Potential

1. Feb 10, 2012

### btpolk

1. The problem statement, all variables and given/known data

For each of the following arrangements of two point charges, find all the points along the line passing through both charges for which the electric potential V is zero (take V = 0 infinitely far from the charges) and for which the electric field E is zero. (Use the following as necessary: Q, d. Enter 0 or ∞ if necessary.)

(a) charges +Q and +2Q separated by a distance d
V = 0: x =
E = 0: x =

(b) charges −Q and +2Q separated by a distance d
V = 0: x =
y =
E = 0: y =
2. Relevant equations

3. The attempt at a solution

(a) V=0: X=∞

2. Feb 10, 2012

### Spinnor

You got the first part of a right (well they said points, so -∞ is also an solution), take a stab at the second part of a.

For b you will need the relevant equations.

3. Feb 10, 2012

### btpolk

For the second part I tried Q+1/4d but it was wrong. I thought that at that point the positive charges would even out at a net electric field of 0.

4. Feb 10, 2012

### btpolk

What relevant equations should I refer to here?

5. Feb 11, 2012