Question

How does the electric potential due to a dipole vary with distance compared to that of a point charge?

Options

• Dipole potential falls as 1/r², point charge as 1/r

• Dipole potential falls as 1/r³, point charge as 1/r²

• Both fall off as 1/r

• Both fall off as 1/r²

Answer 1

The electric potential due to a point charge is \[V = \frac{kQ}{r}\], falling as 1/r. For a dipole, the potential is \[V = \frac{p\cos\theta}{4\pi\varepsilon_0 r^2}\], falling as 1/r². This difference arises because a dipole has zero net charge; the potential decays faster with distance than for a net charge.