Question

The electrostatic potential due to an electric dipole at a distance \( r \) varies as:

• A. \(\frac{1}{r}\)
• B. \(\frac{1}{r^3}\)
• C. \(\frac{1}{r^2}\)
• D. \(r\)

Answer 1

The Correct Option is C

The electrostatic potential V at a point along the axial line of an electric dipole (aligned along the x-axis) is given by:

\( V = \frac{kp \cos \theta}{r^2} \)

where: k is Coulomb's constant, p is the dipole moment (\( p = q \times d \), where q is the charge and d is the separation distance), r is the distance from the dipole to the point where the potential is being calculated, and θ is the angle between the dipole axis and the line connecting the dipole to the point.

Since the potential V is inversely proportional to r², we conclude that the electrostatic potential due to a dipole varies as:

\( V \propto \frac{1}{r^2} \)