I am trying to solve what seems like a simple problem but something is bothering me:
Imagine we have a sphere (1) with a charge $Q_1$ and at a distance $d$ we have another sphere (2) which is a perfect conductor with charge $Q_2 = 0$.
I am trying to calculate the potential that will be induced on this second sphere (2) by the first one.
We assume that the charged sphere (1) can be simplified to a point charge at the centre of the sphere (due to the charge being uniform).
I looked up the method of images in the case of a point charge in the presence of a insulated conductive sphere.
I understand that you have to combine the equations of potential of a grounded conductive sphere (2) and the equation of the potential of a point charge with $Q_3 = Q_2 - Q_1$ at the centre of the conductive sphere (2), but where should I calculate this potential so it's equal to the induced potential of the conductive sphere (2), on the surface ? At the centre?