A proton is taken from point P1 to point P2, both located in an electric field. The electric potentials at points P1 and P2 are -5 V and +5 V, respectively. Assuming that the kinetic energies of the proton at both points P1 and P2 are zero, the work done by the external agent on the proton is:

Two capacitors C1 and C2 are charged to 100 V and 120 V respectively. When connected together in parallel with opposite polarity plates joined together, the net common potential is found to be zero. Therefore, which relation holds true?

Point charges -3Q, -q, 2q, and 2Q are placed, one at each corner of a square. The relation between Q and q for which the electric potential at the centre of the square is zero is: