Physics - Electrostatics Question with Solution | TestHub

Two charge $q_1$ and $q_2$ are placed $30\mathrm{cm}$ apart, as shown in the figure. A third charge $q_3$ is moved along the are of a circle of radius $40\mathrm{cm}$ from $\mathrm{C}$ to $\mathrm{D}$. The change in the potential energy of the system is $\frac{q_{3}k}{4\pi {\in }_0}$, where $k$ is:
NEET 2005