Question

Three point charge -q, +q and -q are placed along straight line at equal distances (say r meter). Electric potential energy of this system of charges will be if +q charge is in the middle.

• A. $\frac{-3q^2}{4\pi {\epsilon }_{0}r}$
• B. $\frac{-8q^2}{3\pi {\epsilon }_{0}r}$
• C. $\frac{-3q^2}{8\pi {\epsilon }_{0}r}$
• D. $\frac{-q^2}{8\pi {\epsilon }_{0}r}$

Answer 1

The correct option is D $\frac{-q^2}{8\pi {\epsilon }_{0}r}$

Point charge $=-q$, $+q$, $-q$

radius $=r$

Electric potential of this system

$V=\frac{1}{4\pi {ϵ}_0}.\frac{-q^2}{2r}$