Q. What is the potential energy of the equal positive point charges of $1\mu C$ each held $1\ m$ apart in air
A) $9 \times 10^{- 3}\ J$
B) $9 \times 10^{- 3}eV$
C) $2eV/m$
D) Zero
Explanation
(a) By using $U = 9 \times 10^{9}\frac{Q_{1}Q_{2}}{r}$
$\Rightarrow U = 9 \times 10^{9} \times \frac{10^{- 6} \times 10^{- 6}}{1} = 9 \times 10^{- 3}\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.