
Moving a charge along an equipotential surface requires zero work. This is due to the zero potential difference between any two points on the same equipotential line. The work done in moving a charge \( Q \) between points with potentials \( V_1 \) and \( V_2 \) is defined as \( W = Q(V_2 - V_1) \). For an equipotential surface, \( V_1 = V_2 \), resulting in \( W = 0 \).
Observing the provided figure, the greatest potential difference is encountered when a charge moves between the 25V and 10V surfaces. Path D represents this scenario. Consequently, the maximum work is performed along path D due to the largest potential difference.
Therefore, path D is identified as the correct answer, as it corresponds to the maximum potential difference and thus the maximum work done.
A point charge \(q = 1\,\mu\text{C}\) is located at a distance \(2\,\text{cm}\) from one end of a thin insulating wire of length \(10\,\text{cm}\) having a charge \(Q = 24\,\mu\text{C}\), distributed uniformly along its length, as shown in the figure. Force between \(q\) and wire is ________ N. 