Physics Question from JEE Main 2026 · 23 January, Shift 2

Two charges $7 \, \mu C$ and $-2 \, \mu C$ are placed at $(-9, 0, 0)$ cm and $(9, 0, 0)$ cm respectively in an external field $E = \frac{A}{r^2}\hat{r}$, where $A = 9 \times 10^5 \, \text{N/C.m}^2$. Considering the potential at infinity is $0$, the electrostatic energy of the configuration is _____ J.