Question

If a point lies at a distance ${}^{\prime }{x}^{\prime }$ from the mid point of the dipole along its axis, the electric potential at this point is proportional to :

• A. $\frac{1}{x^2}$
• B. $\frac{1}{x^3}$
• C. $\frac{1}{x^4}$
• D. $\frac{1}{x^{3/2}}$

Answer 1

Answer: (A)

$\frac{1}{x^2}$

The electric potential of dipole is given by: $V=\frac{pcos\theta }{4\pi {ϵ}_0{r}^2}$
where $r$ is position vector with respect to mid point of dipole and $\theta$ is angle between $r$ and $p$ (dipole moment).
Therefore, electric potential at a point which lies at a distance ′x′′x′ from the mid point of the dipole will be proportional to $\frac{1}{x^2}$.