The center of an electric dipole is placed at the origin, with the axis of the dipole along the x-axis. The dipole moment of the system is , the distance between the two charges is 2a and each charge has magnitude q. The electric potential due to the dipole at a point P, r distance away from the origin, having position vector r depends only on: (given r >> a)

CONCEPT:

• Electric potential is equal to the amount of work done per unit charge by an external force to move the charge q from infinity to a specific point in an electric field.

• Potential due to a single charged particle Q at a distance r from it is given by:

Where, 

ϵ0 is the permittivity of free space and has a value of 8.85 × 10-12 F/m in SI units

EXPLANATION:

• Potential due to a dipole with dipole moment  at a point P(r,θ) having position vector  with respect to the dipole moment orientation is given by (if r >> a):

• Therefore the potential can be calculated if p and r are known.

Therefore option 3 is correct.