# Taking Source Charge As a Reference Point In Deriving Electric Potential?

Just like while calculating gravitational potential energy, we take earth's potential as zero and with respect to that we calculate potential at a point. Similarily in electrostatics why can't we take source charge's potential as zero and not infinity.

Also will the potential at a point a point $$R$$ near charge be different if we take zero Potential at source charge or at infinity?

• The potential is indeed taken to be zero when calculating the gravitational potential energy $-GMm/r$. May 8 '20 at 14:52

• @JoelRodriguez We often do take the zero at infinity for the gravitational potential, for example in the derivation of escape velocity. The only reason we take the zero to be on the floor or on the ground or on the table is for convenience. Anywhere you use $mgh$ you can also use Newton's Law of gravity with the zero of potential at infinity, You'll get the same answer (actually an imperceptibly better answer) at the expense of unnecessary math. It's definitely worth it to do the analysis both ways ($mgh$ and Newton) to see how $mgh$ is accurate near the Earth. Very educational. May 8 '20 at 16:24