Question

Two protons are in a straight line separated by a distance of 4.30 X 10 ^-6m. Charge of a proton = + 1.602 X 10 ^-19 Coulomb. Calculate the potential due to both protons at a point 1.50 X 10 ^-6 m from one of the protons.

Answer 1

The positions of the two protons are shown in the above figure. We want to calculate electric potential due to the two protons at point P. We know that the potential of a point charge q at distance r away from the charge is

where

The potential at point P is the sum of the potential due to the two protons at the point.

where and are the distances between point P and the first and second proton respectively.

Substituting we get