"Invisible" charge? HI all, 1. The problem statement, all variables and given/known data https://www.physicsforums.com/showthread.php?t=427862 See attached picture. q1 is at equal distance from A or B. k = coulomb's constant 2. Relevant equations VA = (k q1 / r) VB = (k q1 / r) 3. The attempt at a solution VAB = VA - VB = 0 V It seems that the charge becomes invisible in that case, right?