# Electrostatic Potential

1. Feb 14, 2010

### LonghornDude8

1. The problem statement, all variables and given/known data
A test charge +q is brought to a point A a distance r from the center of a sphere having a net charge +Q. Next, a test charge +2q is brought to a point B a distance 2r from the center of the sphere.
Compared with the electrostatic potential at A, the electrostatic potential at B is
A. smaller
B. the same
C. greater

2. Relevant equations
V=kq/r
U=kq1q2/r

3. The attempt at a solution
Because you are solving for electric potential I assume that you forget about the charge of the test charges and therefore you would get A. smaller. But if you use the charge of the test charges, you get b. the same. I'm just looking for someone to agree or disagree with me

2. Feb 14, 2010

### kuruman

I agree.
I disagree. As you said, the electric potential set up by the charged sphere is the same at all points in space regardless of how much additional charge you bring in.

3. Feb 14, 2010

### LonghornDude8

Ya, what I said first was right. I just got a little confused because they gave extra info... I hate when that happens.

"I know one thing - that I know no thing." - lol, paradox