Invisible Charge: Solving for Equal Distance in Coulomb's Law

[somasimple]

"Invisible" charge?

HI all,

Homework Statement

https://www.physicsforums.com/showthread.php?t=427862
See attached picture. q₁ is at equal distance from A or B.
k = coulomb's constant

Homework Equations

V_A = (k q₁ / r)
V_B = (k q₁ / r)

The Attempt at a Solution

V_AB = V_A - V_B = 0 V

It seems that the charge becomes invisible in that case, right?

 

[mfb]

The charge is not invisible.

We have (roughly) the same gravitational potential everywhere on the surface of earth. Is Earth invisible? Do you float freely in space?

 

[somasimple]

That's right but its effect on voltage difference is the same as if there was no charge.

 

[voko]

Any charge configuration admits equipotential surfaces. The potential difference between any two points on such a surface is zero. Which does not mean there is no charge.

 

[Nickie]

Yes, in this scenario, the charge appears to be "invisible" as there is no potential difference between points A and B. However, this does not mean that the charge is physically invisible. It simply means that the forces exerted by the charge at points A and B cancel each other out, resulting in no net potential difference. This can occur when the charge distribution is symmetric or when the distance from the charge is equal at both points. It is important to remember that Coulomb's Law describes the relationship between the force exerted by a charge and the distance between that charge and another point, and does not necessarily imply that the charge itself is invisible.