Potential due to Electric Dipole — Prelims Strategy

Prelims Strategy

To excel in NEET questions on potential due to an electric dipole, a systematic approach is essential. First, memorize the core formula: $V = \frac{p \cos\theta}{4\pi\epsilon_0 r^2}$. Understand each term: $p$ is dipole moment, $r$ is distance from center, and $\theta$ is the angle between $\vec{p}$ and $\vec{r}$.

Second, master the special cases: Potential is $\pm \frac{p}{4\pi\epsilon_0 r^2}$ on the axial line ($\theta = 0^circ$ or $180^circ$) and zero on the equatorial line ($\theta = 90^circ$). This zero potential on the equatorial line is a frequent conceptual question.

Third, pay attention to distance dependence: Remember $V_{dipole} \propto 1/r^2$ vs. $V_{point charge} \propto 1/r$. This is a common comparison question. For numerical problems, ensure all units are consistent (SI units are preferred).

Be careful with powers of 10 and decimal calculations. For conceptual questions, always visualize the dipole's orientation and the position of the point. Avoid confusing potential (scalar) with electric field (vector); a zero potential does not mean zero field.

Practice problems involving rotation of dipoles in external fields, as these link potential energy concepts.