An electric dipole consists of two charges +q and -q separated by a distance of 2 cm . What is the work done by an external agent in moving a test charge +Q slowly from a point on the equatorial plane (at a distance of 5 cm from the center of the dipole) to a point on the axial line at a distance of 3 cm from the center (on the side of the positive charge)? (Take K = 1 4 ₀ )

Step-by-step solution

The work done by an external agent in moving a charge +Q is given by W = Q(V_f - V_i) , where V_i and V_f are the initial and final electric potentials respectively. The initial point is on the equatorial plane of the dipole. The electric potential at any point on the equatorial plane of a dipole is zero, so V_i = 0 . The final point is on the axial line at a distance r = 3 cm from the center, on the side of the positive charge. The length of the dipole is 2a = 2 cm , so a = 1 cm . The exact electric potential at a