Q. Identify the WRONG statement
A) The electrical potential energy of a system of two protons shall increase if the separation between the two is decreased
B) The electrical potential energy of a proton electron system will increase if the separation between the two is decreased
C) The electrical potential energy of a proton electron system will increase if the separation between the two is increased
D) The electrical potential energy of a system of two electrons shall increase if the separation between the two is decreased
Explanation
(c) Potential energy as well as force are positive if there is repulsion between the particles and negative if there is attraction.
We take of only the magnitude of values when discussing decrease or increase of energy.
As $P.E. = \frac{Q_{1}Q_{2}}{4\pi\varepsilon_{0}r},$
Plus or minus, i.e., whether both are of the same sign or different, if $r$ decreases, the value increase, Therefore (c) is wrong
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.