Question:
Two equal charges, $2.0^{\times 10^{-7}}$ C each, are held fixed at a separation of $20 \mathrm{~cm}$. A third charge of equal magnitude is placed midway between the two charges. It is now moved to a point $20 \mathrm{~cm}$ from both the charges. How much work is done by the electric field during the process?
Solution:
