In an equilateral triangle, the centroid is equidistant from all vertices. Since all three charges are equal and positive, the electric field vectors at the centroid due to each charge are equal in magnitude and symmetrically placed at \(120^\circ\) to one another.
Due to this symmetry, the vector sum of the electric fields cancels out.
Thus, the net electric field at the centroid is zero.
Two condensers \( C_1 \) & \( C_2 \) in a circuit are joined as shown in the figure. The potential of point A is \( V_1 \) and that of point B is \( V_2 \). The potential at point D will be:
