Question

On the axial line of a dipole (θ = 0°), the electric potential is:

Options

• 0

• \[\frac{2p}{4\pi\varepsilon_0 r^2}\]

• \[+\frac{p}{4\pi\varepsilon_0 r^2}\]

• \[\pm\frac{p}{4\pi\varepsilon_0 r^2}\]

Answer 1

On the axial line, θ = 0° at the positive charge end and θ = 180° at the negative charge end. Using \[V = \frac{p\cos\theta}{4\pi\varepsilon_0 r^2}\], we get \[V = +\frac{p}{4\pi\varepsilon_0 r^2}\] on one end and \[-\frac{p}{4\pi\varepsilon_0 r^2}\] on the other, hence the ± notation.