Question

Two charges +q and -q are palced fixed on the corner of a massless rigid rod of length 2L. Calculate the potential energy of the dipole thus formed.

• A. $\frac{1}{4\pi {ϵ}_0}\frac{q^2}{4L^2}$
• B. $\frac{1}{4\pi {ϵ}_0}\frac{q^2}{2L^2}$
• C. $\frac{1}{2\pi {ϵ}_0}\frac{q^2}{2L^2}$
• D. None of these

Answer 1

The correct option is B

$\frac{1}{4\pi {ϵ}_0}\frac{q^2}{2L^2}$

$PE=\frac{KqV}{r}=\frac{1}{4\pi {ϵ}_0}\frac{q^2}{2L}$