Electrostatic Potential homework

[LonghornDude8]

Homework Statement

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

Homework Equations

V=kq/r
U=kq₁q₂/r

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

 

[kuruman]

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.

I agree.

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

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.

 

[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